Alpha Model Tech Share Series · 2026 · All Scales
Good weathering is not about making the model look old — it is about realism. Restraint, gradation and logical placement are everything. Here is a complete guide to weathering, filtering and chipped paint.

01 · Weathering – Core Concept

The essence of weathering is realism, not simply making the model look "old." Focus on:

• Subtlety
• Restraint
• Gradients
• Logical placement (based on real-world wear and usage)

02 · Weathering Powders / Pastels

Recommended Colors

• Very light grey
• Off-white
• Brown
• Earth yellow
• Dark grey / black

Basic Technique

• Use a dry brush to apply lightly.
• Lighter in the center, slightly darker on the edges.
• Build up gradually — do not apply too much at once.

Body Weathering Logic

(1) Lower Body Dust Accumulation

Areas: lower body panels, wheel arches, lower door edges.

Method:

• Use brown / earth yellow powders.
• Apply from bottom to top.
• Create a gradient (darker at the bottom, lighter upward).
• Avoid hard edges or visible lines.

(2) Wheel Weathering (Brake Dust)

• Lighter center, darker recesses.
• Use dark grey / black powder.
• Tip: apply panel liner first to enhance details, then add powder for a more natural effect.

(3) Tire Oxidation

• Use light grey-black powder.
• Gently brush on the sidewalls.
• Do not paint the entire tire black (it avoids a toy-like look).

(4) Chassis Dirt Effect

• Use brown-grey texture mud or diorama soil.
• Apply locally.
• Simulate real road dirt accumulation.

03 · Chipped Paint Effect

Materials

• Sponge (torn into an irregular shape).
• Paint: silver, red oxide (common primer color).

Steps

1. Dip the sponge lightly into paint.
2. Dab off excess paint on paper or your hand.
3. Gently tap it on the model surface.

Key Areas

• Edges.
• Raised details.
• Frequently worn areas.

Notes

• Avoid large flat surfaces.
• Civilian cars do not have heavy chipping.
• Keep it subtle, random, and minimal.
• Use primer color (e.g., red oxide) for realism.

04 · Filtering Technique

Materials

• Tamiya enamel / oil paint.
• Zippo lighter fluid / enamel thinner (lighter fluid is cost-effective and recommended).
• Flat soft brush.
• Lint-free tissue.

Mixing Ratio

Small amount of paint + large amount of thinner. Dilute to a very transparent, tea-like consistency.

Steps

1. Apply a thin coat from top to bottom across the whole body (simulates rain streaks).
2. Do not wait for it to dry.
3. Immediately use a clean tissue or a slightly damp soft brush to gently wipe the surface.

Desired Effect

• Color remains in panel lines, gaps, and edges.
• Flat surfaces should be mostly clean.
• Let it dry naturally for about 10 minutes.

Alternative: panel liner can also be used to achieve a similar filtering effect.

Color Suggestions

• White body: light grey / light blue.
• Black / dark body: dark grey / light brown.
• Red / blue bright colors: a slightly darker tone of the same color.

05 · Advanced Techniques

(1) Color Variation

• Use very subtle filters in different tones.
• Apply slight variation across panels.
• Simulate sun fading and aging.

(2) Streaking

• Apply small dots of paint on upper areas.
• Pull downward with a clean brush.
• Creates natural rain marks.

(3) Scratches

• Use a very fine brush to draw thin lines.
• Light inside, darker edges.
• Optional silver highlight.

(4) Edge Highlighting (Metal Exposure)

• Dry brush a very small amount of silver.
• Only on the most exposed edges.

06 · Common Mistakes

• Over-weathering (looks dirty rather than realistic).
• Harsh transitions (no smooth gradient).
• Chipping on large flat areas.
• Tires painted solid black.
• Filter too heavy (loses transparency).

07 · Summary

Good weathering is not about adding more, but about controlling effects. Remember three key principles:

• Restraint
• Realism
• Gradation

If it looks like natural wear instead of intentional aging, you have done it right.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · All Scales
Getting a clear part to sit cleanly in the body opening takes patience and the right technique. Here is the complete windshield installation workflow, including curved-glass handling and Alpha Model's practical tips.

01 · Tools Required

• Hobby knife
• Tweezers
• Cotton swabs
• Masking tape
• Clear-parts adhesive / windshield glue
• Fine sandpaper (2000–3000 grit)
• Polishing compound
• Soft cloth

02 · Surface Preparation (Critical)

Before installing the windshield, ensure both the body opening and the clear part are clean and free of dust and oil:

• Lightly sand the opening edges with 2000–3000 grit sandpaper to remove burrs.
• Clean the clear part with isopropyl alcohol for proper adhesion.
• Always test fit before applying any adhesive.

03 · Handling Curved Glass

• Use tweezers to avoid fingerprints and scratches.
• Do NOT apply excessive force to prevent cracking.
• For large curvature, perform pre-forming (see Step 06).

04 · Adhesive Selection

• Clear-part dedicated adhesives are preferred.
• General-purpose option: TAMIYA CRAFT BOND (water-based) — dries clear, low risk of fogging, suitable for transparent parts.
• Apply adhesive in a thin layer to avoid overflow.

05 · Installation Steps

1. Apply a thin, even layer of adhesive around the windshield opening.
2. Hold the part with tweezers and position it carefully.
3. Press gently from one side and work across.
4. Remove excess glue with a damp cotton swab.
5. Let it cure for about 1 hour before handling.

06 · Complex Curvature Methods

Method A — Warm Water

• Soak in 40–50°C water for 30–60 seconds.
• Work quickly after removal.
• Fix in sections using masking tape.

Method B — Heat Gun

• Use low heat at a 10–15cm distance.
• Keep moving to avoid overheating.
• Shape gradually while heating.
• A hairdryer can be used as an alternative.

07 · Alpha Model Practical Techniques (Key Section)

Protective Film Strategy

• Do NOT remove the protective film before installation.
• After applying adhesive, fix all edges with masking tape.
• Apply gentle heat with a heat gun.
• Let it sit for 12 hours to fully cure.
• Remove the film only after curing.

Curvature Pre-Forming Technique

• Place the clear part onto a soda can or beer bottle.
• Fix with masking tape.
• Leave for 24 hours to form a natural curve.
• Choose the container diameter based on the required curvature.
• No need for perfect conformity — slight curvature is sufficient.
• This helps prevent edge lifting during installation.

Strong Bonding Option

• If bonding is difficult, use Bond G17 quick adhesive.
• Strong adhesion, but apply carefully in small amounts.

08 · Polishing & Transparency Enhancement (Advanced)

Method A — Pledge Floor Wax Dip

• Use a floor polish (e.g., Pledge).
• Pour it into a paper cup.
• Dip the clear part and remove it with tweezers.
• Place it on a support to air dry.
• Put paper underneath to catch drips.
• Result: significantly improved clarity and gloss.

Method B — Modeling Wax

• Use TAMIYA Modeling Wax.
• Enhances gloss and transparency.
• Better suited for fine model finishing.

09 · Finishing

• Lightly polish with a soft cloth and compound if needed.
• Clean any adhesive residue with alcohol.
• Inspect from multiple angles to ensure a proper fit.

10 · Common Mistakes to Avoid

• Using too much adhesive.
• Handling before full curing.
• Applying excessive pressure.
• Skipping the test fit.
• Overheating causing deformation.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · 1/24, 1/43 Scale
Resin engine parts are softer and easier to carve than injection plastic, giving you room to add realistic pipes and surface detail. Here is the full modification workflow.

01 · Understanding Resin Part Properties

• Resin is brittle — work gently when sanding.
• Fully cured resin can be carved using sandpaper and modeling knives.
• Small gaps and details can be filled with A-B clay or glue.

02 · Basic Steps for Pipe Replication

1. Study Reference Photos

Before modifying, gather photos of real engines as reference. Pay attention to pipe routing, diameter changes, and connection methods.

2. Creating Pipes

Choose materials based on the scale of your model:

• Copper wire: ideal for thicker pipes, can be bent into natural curves.
• Nylon tubing: soft and flexible, great for curved intake pipes.
• Plastic rod drawing: heat with a hot air gun and pull into thin tubes for small fuel lines.
• Model-specific tubing: professional materials with various diameter specifications.
• Medical tubing: soft texture, good for curved effects.
• PE etched sheets: perfect for flat-shaped intake pipes.

3. Drilling Mounting Points

Gently drill holes at the corresponding mounting points on the engine part, matching the routing of real engine pipes.

4. Adhesive Installation

Secure the pipes to the parts using 502 glue (CA adhesive) or A-B epoxy. Be careful not to use too much glue to avoid overflow affecting the appearance.

03 · Filling and Refinement

This is the key step to achieving a perfect finish:

• Use putty to fill gaps, dents, and imperfections.
• Refine pipe curves for smooth transitions.
• Shape joints to match real pipe routing.
• Sand smooth for a clean, even surface.

04 · Texturing Techniques

1. Sandpaper sanding — progress through different grits (from 400 to 2000) to simulate the smooth surface of real metal.
2. Surface texturing — lightly sand the pipe surface to create a matte finish, mimicking real metal texture.
3. Engraving details — use scribing tools or fine awls to engrave panel lines and rivet positions for added realism.
4. Adding fine details — add small details like wiring wraps and clamps to restore the texture of real engine pipes.
5. Panel lining — use panel lining fluid or thinned paint to outline detail lines, adding depth and dimension to the engine surface.

05 · Painting Suggestions

• Metallic spray paint: apply thin multiple coats to avoid paint build-up.
• Weathering effects: add rust, oil stains, dust, and other effects based on your desired style.
• Gloss finish: use gloss varnish on engine block areas to simulate metallic reflections.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · Resin Kits, All Scales
In resin model building, assembly fitment refers to how well parts fit together. Because resin shrinks more than plastic injection, part interfaces can develop gaps that are too large or too tight — here is how to adjust them for a perfect fit.

01 · What is Assembly Fitment?

Assembly fitment describes how well parts fit together when joined. Resin material has a higher shrinkage rate, so interfaces may develop gaps that need adjusting to achieve a perfect fit.

Common Issues:

• Uneven gaps between parts.
• Clips failing to engage properly.
• Parts requiring excessive pressure to install.

02 · Body Shell Alignment Techniques

The body shell is the most visible part of the model — misalignment will directly affect the overall appearance.

Adjustment Steps

1. Dry Fitting — before applying any adhesive, place the body shell on the chassis and check that the left and right clearances are even.
2. Positioning Marks — use a pencil to lightly mark the corresponding positions on the chassis to ensure consistent placement every time.

Fine-Tuning Methods

Gaps too large: use putty filler.

• First pass: use 800-grit putty for initial leveling.
• After confirming the shape is correct, finish with 2000-grit putty for a smooth, paint-ready surface.

Gaps too tight: lightly sand the body shell edges with sandpaper.

Adhesive Fixing

Once alignment is confirmed, use CYANON 400 Instant Adhesive combined with Activator for fast, strong bonding. For lower odor and more even curing, consider using the Low-Odor DW Curing Agent.

03 · Aftermarket Parts Guide

Aftermarket parts are third-party upgrade components used to enhance model detail or replace original parts.

Common Types:

• Metal etched parts (PE).
• Resin modified body shells.
• Metal chassis reinforcement parts.
• Independent headlight optical lenses.

Recommended Brand: Hobby Design

As the sister brand of Alpha Model, Hobby Design specializes in providing high-quality upgrade parts for automotive model enthusiasts.

Hobby Design Product Highlights:

• Precision Metal Etched Parts: premium stainless steel, sharp details, resistant to deformation.
• Resin Modified Body Shells: designed for modifying and enhancing Tamiya and Aoshima original body shells, filling in missing factory details and improving the overall finish.
• Independent Headlight Optical Lenses: high-transparency PMMA material that recreates realistic headlight effects.
• Chassis and Engine Detail Sets: greatly enhance model visual appeal.

Why Choose Hobby Design?

1. Extensive Selection: a comprehensive range of model-specific upgrade parts — whatever upgrade you need, you will almost certainly find the right option.
2. Perfect Compatibility: Alpha Model kits are already highly complete, requiring minimal modification. Hobby Design is primarily designed for Tamiya and Aoshima plastic kits, filling the detail gaps left by those manufacturers' original parts.
3. Quality Assurance: the same production and quality-control standards as Alpha Model.
4. Limited Production: some parts are produced in limited quantities, offering collectible value.

Installation Notes

1. Compatibility check — confirm the parts suit your model brand and scale before purchasing.
2. Pre-assembly test (mock fit) — all aftermarket parts must be mock-fitted before permanent adhesion. Pay special attention to curved parts like air ducts — remove and fine-tune them during the mock fit.
3. Fine adjustment — for curved etched parts (air ducts, spoilers, etc.), gently bend them to adjust the curve. If the curve is difficult to shape, use a heat gun to lightly warm the part before bending — be careful not to overheat and deform it.
4. Surface treatment — metal parts may require polishing or painting to match the model's overall finish.
5. Precision handling — handle small etched parts with pointed tweezers, avoiding bare hands to prevent oil marks.

04 · Recommended Tools

05 · Frequently Asked Questions

Q: What if the body shell gap is too large?
A: Use 800-grit putty for the first fill to level the surface. After confirming the shape, apply 2000-grit putty for a fine finish, then sand smooth and apply paint.

Q: The etched part won't stick?
A: Make sure the surface is clean and free of oil. Wipe with alcohol before adhesion. For curved parts, gently heat with a heat gun before bending to adjust.

Q: A resin part is too hard to remove?
A: Never force it out — gradually sand and adjust, or contact the manufacturer for a replacement.

Q: The adhesive smell is too strong?
A: Use a low-odor DW Curing Agent, work in a well-ventilated area, and use an activator to speed up curing.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · Resin Kits, All Scales
In resin model building, assembly fitment refers to how well parts fit together. Because resin shrinks more than plastic injection, part interfaces can develop gaps that are too large or too tight — here is how to adjust them for a perfect fit.

01 · What is Assembly Fitment?

Assembly fitment describes how well parts fit together when joined. Resin material has a higher shrinkage rate, so interfaces may develop gaps that need adjusting to achieve a perfect fit.

Common Issues:

• Uneven gaps between parts.
• Clips failing to engage properly.
• Parts requiring excessive pressure to install.

02 · Body Shell Alignment Techniques

The body shell is the most visible part of the model — misalignment will directly affect the overall appearance.

Adjustment Steps

1. Dry Fitting — before applying any adhesive, place the body shell on the chassis and check that the left and right clearances are even.
2. Positioning Marks — use a pencil to lightly mark the corresponding positions on the chassis to ensure consistent placement every time.

Fine-Tuning Methods

Gaps too large: use putty filler.

• First pass: use 800-grit putty for initial leveling.
• After confirming the shape is correct, finish with 2000-grit putty for a smooth, paint-ready surface.

Gaps too tight: lightly sand the body shell edges with sandpaper.

Adhesive Fixing

Once alignment is confirmed, use CYANON 400 Instant Adhesive combined with Activator for fast, strong bonding. For lower odor and more even curing, consider using the Low-Odor DW Curing Agent.

03 · Aftermarket Parts Guide

Aftermarket parts are third-party upgrade components used to enhance model detail or replace original parts.

Common Types:

• Metal etched parts (PE).
• Resin modified body shells.
• Metal chassis reinforcement parts.
• Independent headlight optical lenses.

Recommended Brand: Hobby Design

As the sister brand of Alpha Model, Hobby Design specializes in providing high-quality upgrade parts for automotive model enthusiasts.

Hobby Design Product Highlights:

• Precision Metal Etched Parts: premium stainless steel, sharp details, resistant to deformation.
• Resin Modified Body Shells: designed for modifying and enhancing Tamiya and Aoshima original body shells, filling in missing factory details and improving the overall finish.
• Independent Headlight Optical Lenses: high-transparency PMMA material that recreates realistic headlight effects.
• Chassis and Engine Detail Sets: greatly enhance model visual appeal.

Why Choose Hobby Design?

1. Extensive Selection: a comprehensive range of model-specific upgrade parts — whatever upgrade you need, you will almost certainly find the right option.
2. Perfect Compatibility: Alpha Model kits are already highly complete, requiring minimal modification. Hobby Design is primarily designed for Tamiya and Aoshima plastic kits, filling the detail gaps left by those manufacturers' original parts.
3. Quality Assurance: the same production and quality-control standards as Alpha Model.
4. Limited Production: some parts are produced in limited quantities, offering collectible value.

Installation Notes

1. Compatibility check — confirm the parts suit your model brand and scale before purchasing.
2. Pre-assembly test (mock fit) — all aftermarket parts must be mock-fitted before permanent adhesion. Pay special attention to curved parts like air ducts — remove and fine-tune them during the mock fit.
3. Fine adjustment — for curved etched parts (air ducts, spoilers, etc.), gently bend them to adjust the curve. If the curve is difficult to shape, use a heat gun to lightly warm the part before bending — be careful not to overheat and deform it.
4. Surface treatment — metal parts may require polishing or painting to match the model's overall finish.
5. Precision handling — handle small etched parts with pointed tweezers, avoiding bare hands to prevent oil marks.

04 · Recommended Tools

05 · Frequently Asked Questions

Q: What if the body shell gap is too large?
A: Use 800-grit putty for the first fill to level the surface. After confirming the shape, apply 2000-grit putty for a fine finish, then sand smooth and apply paint.

Q: The etched part won't stick?
A: Make sure the surface is clean and free of oil. Wipe with alcohol before adhesion. For curved parts, gently heat with a heat gun before bending to adjust.

Q: A resin part is too hard to remove?
A: Never force it out — gradually sand and adjust, or contact the manufacturer for a replacement.

Q: The adhesive smell is too strong?
A: Use a low-odor DW Curing Agent, work in a well-ventilated area, and use an activator to speed up curing.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · All Scales
Paint defects are among the most common frustrations in model building. The good news is — most of them can be fixed. Here are solutions for the most common paint issues.

01 · Orange Peel

Appearance: bumpy, textured surface resembling an orange peel.
Cause: spraying too far away, applying too thick coats, high air pressure, or fast-evaporating thinner.

Solution:

• Sand gently with 2000–3000 grit sandpaper using a GodHand sanding block (GH-KS10).
• Polish with compound and finish with a clear coat for protection.
• When respraying: keep an 8–13cm distance, apply thin coats, and control air pressure.

02 · Runs & Sags

Appearance: paint drips or sags forming tears or streaks.
Cause: applying too much paint at once, moving the airbrush too slowly, or pausing on edges.

Solution:

• If wet: blot up excess paint with a brush or absorbent paper.
• If dry: sand smooth with the GodHand block and respray.
• Edge technique: flick your wrist quickly at sharp edges — never pause there.
• Prevention: thin coats, 5-minute intervals between coats, 2–3 coats total, never spray heavy in one pass.

03 · Paint Build-Up & Pooling in Recesses

Appearance: excessive paint accumulates in grooves and corners with uneven thickness.
Cause: improper spray angle causes paint to flow and pool in low areas.

Solution:

• Use the GodHand sanding block to carefully flatten overbuilt areas.
• Cross-coat method: first pass horizontal, second pass vertical to avoid dead spots.
• Maintain consistent speed — start moving before pulling the trigger, release after finishing the pass.

04 · Dust & Particles

Appearance: dust or fibers embedded in the paint surface.
Cause: unclean spraying environment or dusty workbench.

Solution:

• Small particles: once dry, sand lightly with 2000 grit, polish and clear coat.
• Large particles: sand down to base and respray the entire panel.
• Prevention: clean the body with a tack cloth before spraying, strain paint through a filter.

05 · Uneven Coverage

Appearance: base color showing through or uneven color distribution.
Cause: not enough coats, dirty primer, incorrect thinner ratio.

Solution:

• Ensure the primer coat is flat, clean, and free of oil.
• Apply more coats, keeping each one thin.
• Check the thinner ratio (typically paint:thinner = 1:1 to 1:2).
• Some colors like yellow and red need more coats for full coverage.

06 · Blistering

Appearance: small bubbles or blister-like bumps appearing on the paint surface.
Cause: paint drying too fast, primer not fully cured, or moisture intrusion.

Solution:

• Sand off the blistered area.
• Confirm the base is completely dry before respraying.
• When humidity > 70%: use retarder thinner to prevent blushing.
• When temperature < 15°C: increase the thinner ratio, use fast-dry thinner.
• Check if the paint is expired or degraded.

07 · Metallic Flaking / Flotation

Appearance: metallic flakes distributed unevenly, looking cloudy or whitish.
Cause: unstable spray pressure, wrong thinner type, or spraying too close.

Solution:

• Minor issues can be fixed with polishing.
• Severe cases require sanding and respraying.
• Use dedicated metallic paint thinner, maintain steady pressure and an 8–13cm distance.
• Never touch up metallic paint with a brush.

08 · About Paint Stripper

If you need to start over, simply soak the part in Yoshikawa paint stripper.

• After soaking, filter with filter paper and save the stripper for reuse.
• Paint stripper can be reused — no need to replace it frequently.
• To redo a single panel: strip the entire panel down to bare plastic, never spot-repair panel by panel.

09 · About Drying Time

After spraying, allow at least 24 hours of drying time at room temperature before applying the clear coat. Applying the clear coat too soon will cause bubbling and cracking.

10 · Recommended Tools

11 · Spraying Golden Rules

1. Distance: keep the airbrush 8–13cm from the workpiece.
2. Movement: consistent speed — start moving BEFORE pulling the trigger, release AFTER finishing the pass.
3. Coats: 5-minute intervals, 2–3 thin coats only.
4. Pattern: cross-coat method (horizontal, then vertical).
5. Edges: quick wrist flick at sharp corners, never pause.
6. Drying: wait a minimum of 24 hours before clear coat.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · 1/24, 1/43 Scale
A well-fitted chassis and clean suspension are the foundation of any great build. Here is the full process from parts prep to suspension, drivetrain, wheels and underbody details.

01 · Chassis Parts Preparation

Cleaning Steps

1. Soak the parts in warm detergent water (40–50°C) for 15–20 minutes.
2. Gently brush grooves and holes with a soft-bristled brush.
3. Rinse with clean water and air dry.

Note: do not use hot water — it may cause resin deformation.

Removing Flash

• Use side cutters to remove large gate material.
• Gently shave off remaining residue with a hobby knife held flush against the part surface.
• File flat and finish with 2000-grit sandpaper.

Filling Sink Marks

1. Sand around the air bubble with 800-grit sandpaper.
2. Press Tamiya putty into the void.
3. After fully drying, flatten with 800-grit, then refine with 2000-grit.

02 · Chassis Assembly

Trial Fit (Required Step)

1. Place the parts without applying glue.
2. Confirm left-right symmetry and front-back alignment.
3. Check that the clearance is sufficient.
4. Adjust promptly if issues are found.

Bonding Sequence

1. Bond the chassis main body first (if multi-part).
2. Install the engine mount and align the front edge.
3. Centre and bond the drivetrain channel strips.

03 · Suspension Fabrication

Control Arm Installation

• Bond the upper and lower control arms into the chassis mounting holes.
• Ball joint shapes face outward.
• Angles must be symmetrical on both sides.
• Tip: use Blu-Tack for temporary hold and confirm angles before gluing.

Shock Springs

• Mask connecting areas before painting.
• Spring colors: red / yellow / gold.
• Slightly compress during installation, glue once the fit is confirmed.

Anti-Roll Bar

• Use photo-etch or 0.5mm copper wire.
• Connect to the left-right control arm mounting holes at both ends.
• Confirm free movement before gluing.

04 · Drivetrain System

Engine Assembly

1. Bond engine and transmission together first.
2. Install the entire assembly to the chassis mount.
3. Align front-rear position and ensure the driveshaft can connect.

Differential

• Align with the chassis slots or mounting holes.
• The crown gear faces the correct direction.
• Secure all sides with glue after fully curing.

Driveshaft Fabrication

1. Cut a 0.8–1.0mm brass rod to match the available length.
2. Flatten or grind both ends into universal joint shapes.
3. Give the driveshaft a slight arc.

Driveshaft Installation

1. Insert one end into the differential output flange first.
2. Adjust the angle to align with the front wheel hub position.
3. Trial fit to confirm length, then glue once the fit is confirmed.

05 · Wheel Assembly

Brake Discs

• Install brake discs to the wheel hub carrier first.
• For two-piece units, bond the bell first, then fit the brake disc over it.
• Confirm the bolt holes are aligned.

Brake Calipers

Painting: mask the mounting surfaces, then spray the brand color.

Installation: align with the wheel hub mount, press in, and lightly glue to secure.

Wheel Hubs

1. Install the brake disc and caliper first.
2. Centre the wheel hub with the carrier.
3. The logo on the centre cap faces the correct direction.

Tires

• Stretch the rubber ring onto the wheel hub.
• Important: before installing, check the tire tread direction against the instructions to ensure correct pattern orientation.
• If too loose, apply a small amount of rubber glue to secure.
• Do not glue the entire circumference — leave some flexibility.

06 · Chassis Underbody Details

Exhaust Pipe Fabrication

1. Bend a 0.8–1.0mm brass rod.
2. Draw the routing path on paper first, then gradually bend.
3. Spray Gunze Super Silver HSM01.
4. Scrape the inside of the pipe tip to create a heat-blue color.

Brake Lines

• Use 0.3mm plastic tubing or copper wire.
• Extend from the main reservoir to the front and rear wheels.
• Add slight arcs to convey softness.

Diffuser

• Aerodynamic component under the rear chassis.
• Bond multiple photo-etch sheets in sequence.
• The fin angles flare outward.
• Handle carefully with tweezers.

07 · Painting Process

08 · Common Problems and Solutions

09 · Tool List

• Side cutters, hobby knife (#11), files, sanding sticks (2000 grit).
• 502-style instant glue, Blu-Tack, PVA white glue.
• Gunze primer B-001, paints, clear coat B-502/B-503.
• Needle-nose pliers, flat-nose pliers, tweezers.
• Brass rod (0.8–1.0mm), plastic tubing (0.3mm).

10 · Aftermarket Brands

Hobby Design / Studio27 / Metal York / Reed Holly / Master Model

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · 1/24, 1/43 Scale
GT3 interiors are dense with detail — roll cages, dashboards, bucket seats and bundled wiring. Here is how to assemble the interior cleanly and add believable wiring and detail.

01 · Interior Parts Preparation

Unboxing Inspection

• Cross-reference the instructions to verify all components: dashboard, seats, steering wheel, roll cage, pedals, etc.
• Check for flash, missing material or breakage.
• Inspect thin-walled parts (dashboard edges, steering column) for damage.
• Confirm photo-etched (PE) parts are not curled or missing.

Cleaning Parts

1. Soak in warm detergent water (40–50°C) for 15 minutes.
2. Gently brush with a soft-bristled brush, especially dashboard vents and seat gaps.
3. Rinse with clean water and blot dry.
4. Air-dry completely in a ventilated area (at least 1 hour).

Note: do not use hot water — it may cause resin deformation.

Removing Flash

• Use a sharp hobby knife (#11) for fine areas like dashboard edges and seat corners; fine files for larger areas; sanding sticks (2000 grit) for final finishing.
• Work the blade flush and shallow, especially on thin walls — use the blade tip for light touch-ups.

Filling Sink Marks and Air Bubbles

1. Sand around the bubble with 800-grit to roughen.
2. Press putty into the void and smooth.
3. Flatten with 800-grit when dry, refine with 2000-grit.
4. For large areas, apply in layers to avoid filling too thick at once.

Note: putty on dashboard surfaces should be very thin — fill only the depression without affecting flatness.

02 · Interior Assembly

Roll Cage

PE roll cage: bend each tube with needle-nose pliers (main hoop first, then door crossbars), sand intersections if too thick, hold temporarily with Blu-Tack and fix with CA once aligned.

Resin roll cage: check the crossbar slots are cleanly cut, insert crossbars in sequence, apply small CA dots at connections.

Install to chassis: align mounting holes, temporarily fix with Blu-Tack, confirm vertical alignment, then glue from top to bottom.

Dashboard

1. Dry fit into the front chassis section — confirm the bottom protrusions fit the slots, sides do not exceed the body contour, and the steering column aligns with the wheel.
2. Apply small CA dots to the bonding surfaces, press in, use Blu-Tack for support while curing, then check flatness.

Steering Wheel and Column

Glue the column to the back of the dashboard first (vertical, not tilted), then align the wheel's centre hole with the column top. If loose, secure with a small CA or epoxy dot.

Seats

Bucket-style seats install at the chassis centre: clear flash from the seatbelt holes, optionally carve texture into the seat creases, align with the two mounting slots, confirm vertical and left-right symmetry, then fix with small CA dots.

Centre Console

The console sits in a very tight space between dashboard and seats: confirm the gear shifter position and path, align the console, align the shifter base with the shift mechanism, temporarily fix from below with Blu-Tack, and confirm buttons/switches are not tilted.

03 · Wiring Harness Fabrication and Routing

The wiring harness is a decorative detail that simulates a real race car's dense wiring. You do not need to replicate the complete real path — just detailed representation in key areas.

Material Selection

Engine Bay Harness

(most complex) Thread 0.2–0.3mm stretched sprue or fine copper wire from the firewall forward, splitting into a few thin bundles routed separately to the airflow sensor, coolant temperature sensor and throttle position sensor. Add tiny glue dots at each wire end and bend gently for natural curves.

Optional color coding: red = positive (+), black = negative (−), yellow = signal, blue = auxiliary.

Dashboard Harness

Run fine sprue or copper wire from the firewall rearward to behind the dashboard, splitting into thinner wires to the gauge cluster, switch panel and steering column switches. Use 0.1–0.2mm stretched sprue — these wires are very fine — and secure with tiny Blu-Tack dots rather than much glue.

Taillight Harness

Use 0.2mm copper wire from inside the chassis (near the fuel tank area) rearward, route along the inner wall, branch left and right to the taillights, and slightly flare the wire ends to simulate connectors.

Securing Tips

• CA glue dots — very small amounts every 2–3mm.
• Blu-Tack dots — for areas needing adjustment.
• Plastic clips — PE clips or homemade clips.
• Harness should have natural curves, never pull too straight.
• Leave some play when passing through holes; keep wiring close to the body surface, not suspended.

04 · Interior Detail Work

Seatbelts

PE seatbelt kits (recommended): Studio27 and Hobby Design offer dedicated sets — fold belt shapes per instructions, bend buckles with tweezers, install to seat sides and roll cage.

DIY seatbelts: cut 0.1mm plastic sheet or Tamiya masking tape into 2–3mm strips, glue one end to the seatbelt hole, loop the other around a roll cage crossbar, carve webbing texture with a fine knife. Black webbing is most common; also grey or team-livery red, with silver or gunmetal buckles.

Dashboard Details

• Gauge faces: use white sticker paper and hand-draw scales for extra detail; pointers in black or red.
• Stickers: clean surface first, press gently with Blu-Tack to avoid bubbles; prick bubbles with a needle tip to release.

Pedal Set

Pedals (throttle, brake, clutch) sit at the front of the chassis: insert the pedal shaft into the front mounting holes, hang the three pedals on the shaft, confirm the arms slightly pivot (for appearance only), and secure the shaft ends with Blu-Tack.

Photo-Etch Details

Common PE parts: vent grilles, dashboard trim, button panels and seatbelt buckles. Grip the part edge with tweezers, temporarily fix with Blu-Tack, then secure with a minimal amount of CA — PE parts are very thin.

05 · Interior Painting Process

Masking Before Painting

Mask dashboard and seat bonding surfaces, roll cage connections, ball joints and mounting holes, and wheel hub centres. Use Blu-Tack for irregular curves, masking paper for flat surfaces, and solvent-resistant tape for fine edges.

Primer

Spray 2–3 thin coats of grey primer; allow 5 minutes between coats, then dry 24 hours before topcoat.

Topcoat Colors

• Interior body — semi-gloss black or matte black (some GT3 interiors are dark grey).
• Gauge faces — black + white sticker scales; vents — black inner walls, silver blades; switch buttons — red (horn), green (lights), black (others).
• Steering wheel — matte black tire, silver or carbon spokes.
• Seats — matte black with dry-brushed webbing texture.
• Roll cage — silver/brass or graphite black.

Weathering (Optional)

Race-used cars show light grime: dry-brush light grey on the steering wheel at 3 and 9 o'clock, sweep brown on seat creases, brush black on pedal surfaces. At 1/43, keep weathering very subtle — overdoing it looks unrealistic.

Clear Coat

After primer and topcoat fully dry (at least 24 hours), spray a thin coat of clear coat and allow to dry before assembly.

06 · Interior Assembly Sequence

1. Roll cage — glue to the chassis position, confirm vertical and symmetric, let cure.
2. Wiring pre-routing — route engine bay, dashboard and taillight harnesses, confirm natural routing, secure temporarily.
3. Dashboard — align with the front chassis, bond, check the gap with the front crossbar.
4. Steering column and wheel — glue to the dashboard rear, install the wheel, confirm angle.
5. Centre console — align between dashboard and chassis, align the shifter, fix with Blu-Tack.
6. Seat installation — align with the centre mount, bond from bottom or side.
7. Seatbelt installation — glue one end to the seat, loop the other around the crossbar, adjust tension.
8. Pedal set — insert the shaft, hang the pedals, confirm pivoting.
9. Photo-etch details — vent grilles, dashboard trim, button panels; work top to bottom, inside to outside.
10. Final inspection — check all bonds secure, components centred and symmetric, excess glue cleaned, nothing missed.

07 · Common Problems and Solutions

08 · Recommended Aftermarket Brands

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · All Scales
During mould making and casting, resin parts can suffer shrinkage, air bubbles and warpage. Here is how to diagnose each defect and repair it to a clean, level finish.

01 · Understanding Resin Casting Defects

• Shrinkage — the part shrinks in volume after cooling, causing undersized dimensions, sink marks on edges and increased fitting gaps.
• Air bubbles — air not expelled during pouring forms voids on the surface or inside the part.
• Warpage — after demolding, parts warp or twist from internal stress release and no longer sit flat.

02 · Fixing Shrinkage Issues

Common Signs of Shrinkage

• Sink marks appearing on part edges.
• Noticeably increased gaps at fitting surfaces.
• Screw holes shifted or reduced in diameter.

Repair Methods

Minor sink marks:

1. Lightly sand the area with 800-grit paper.
2. Fill the depression with a paste of 502 glue (cyanoacrylate) mixed with baby powder.
3. When fully dry, flatten with 800-grit, then finish with 2000-grit for a smooth surface.

Larger dimensional deviations:

1. Measure the original design dimensions and the actual deviation.
2. Apply thin coats of epoxy putty where buildup is needed, and sand to shape after curing.
3. For oversized fitting gaps, insert 0.1–0.2mm shims (plastic or paper) as compensation.

03 · Fixing Air Bubble Issues

Common Locations of Air Bubbles

Small pits on the part surface (pop bubbles) · internal voids in thick sections · fine detail areas and corners.

Repair Methods

Surface micro-bubbles:

1. Poke open the bubble hole with a toothpick or fine needle.
2. Fill with the 502 glue + baby powder mixture.
3. Sand smooth after drying.

Deeper voids:

1. Thin down the surrounding area with 800-grit to expose a clean surface.
2. Spray a thin coat of surface primer to reveal hidden bubbles underneath.
3. If found, continue filling and sanding; if not, fill flat with epoxy putty, then sand.

Internal large bubbles (affecting structural strength):

1. Saw or grind open the part to expose the bubble.
2. Fill with two-part epoxy resin (5-minute epoxy).
3. Clamp tight, allow to cure, then sand and polish to restore shape.

04 · Fixing Warpage Issues

Common Causes of Warpage

• Demolding too early, before the resin is fully cured.
• Uneven cooling at thick-thin junctions.
• External force during curing, or the mould not placed level.

Correction Methods

Minor warpage (slight edge lifting):

1. Soak the part in hot water (60–70°C) for 1–2 minutes to soften the resin.
2. While hot, press the part flat on a glass plate or flat board.
3. Place a weight on top and let it cool to room temperature before removing.

Moderate warpage (obvious twist but recoverable):

1. Prepare a flat board matching the part size.
2. Sand the concave side rough to improve bonding.
3. Apply a thin layer of epoxy or 502 glue and attach a 0.5–1mm reinforcement plate (plastic or carbon fiber).
4. Clamp tight and allow to fully cure.

Severe warpage (beyond correction): recommend re-casting — it cannot be restored to acceptable quality through repair.

05 · Chassis and Body Shell Reaming

Body shell chassis mounting holes and screw holes usually need reaming before installation. Alpha Model body shells have small original holes; directly driving screws may not fit or tighten properly.

1. Ream holes to 2.1mm so screws pass through smoothly and secure firmly.
2. First, use a small drill bit matching the original hole to remove burrs and chamfers.
3. Then step up gradually (1.5mm, 1.8mm, 2.1mm), reaming step by step.
4. Keep the drill perpendicular to the chassis plane to avoid tilted holes.
5. Test fit with a 2.1mm screw to confirm smooth insertion.

Note: confirm screw specifications before reaming. 2.1mm is the standard hole size for Alpha Model chassis.

06 · Tools and Materials Checklist

07 · Practical Tips

• Never fill too thick in one pass — apply in thin layers, letting each dry fully to avoid creating new bubbles and shrinkage.
• Always test sand after filling — hold the part sideways under a light to see high and low spots clearly.
• Internal bubbles are hardest to fix — tap lightly and listen; hollow areas sound duller.
• Warpage correction must be done while hot — once the part softens, press flat immediately; it will not work once cooled.
• When reaming chassis holes, do not skip steps — ream gradually to avoid the bit binding or hole-wall chipping.

Build. Detail. Inspire. — Alpha Model Technical Team

Alpha Model Tech Share Series · 2026 · All Scales
Vacuum-formed lenses are thin and easy to trim unevenly. Here is a careful, step-by-step approach to trimming headlight, taillight and instrument lenses so they fit cleanly into the body shell.

01 · Understanding Vacuum-Formed Lenses

Vacuum-formed lenses are transparent or semi-transparent plastic sheets formed by vacuum adsorption, commonly used for headlight lenses, taillight lenses, turn signal lenses and instrument cluster covers. They are relatively thin (usually 0.3–0.8mm), and the excess material around the edges must be trimmed before the lens installs onto the body shell.

02 · Preparation Before Trimming

Identifying the Lens Edge Line

After vacuum forming, flash (excess material) remains around the edges as an irregular, thick border:

1. Place the lens flat on the table.
2. Gently press around the lens edge to feel the flash location and thickness.
3. Flash is typically 2–3× thicker than the lens body and is easy to identify.

Securing the Lens

• Place a layer of felt or silicone pad underneath the lens to increase friction.
• Temporarily adhere the lens with Blu-Tack or double-sided tape.
• For larger sections, use binder clips on the four corners.

Tool Selection

03 · Trimming Methods

Removing Large Areas of Flash

1. Hold the hobby knife like a pen, blade at about 30° to the surface, and cut along the inside of the flash (closer to the lens body) at a steady pace.
2. Never cut deeper than 0.5mm per pass — do not try to cut through in one stroke.
3. For straight edges, use a steel ruler as a guide.
4. Work gradually, pausing after each cut to check the line.
5. For softer material, sharp-pointed scissors work directly along the boundary with better control.

Note: start cutting at the boundary between flash and lens body to preserve the complete lens edge — never cut at the centre of the lens.

Fine Trimming

1. Flip the lens over and check the cut edge is even.
2. Lightly sand with 2000-grit paper using single-direction strokes (do not scrub back and forth).
3. Drip a small amount of water while sanding to cool and reduce static that attracts dust.
4. Run a fingernail along the edge — any roughness means flash remains.

Handling Curves and Corners

• Large curves: use sharp-pointed scissors, trim no more than 1mm at a time, compare fit after each cut, and keep the scissors perpendicular to the lens plane to avoid beveling the edge thin.
• Sharp corners: score an initial notch with the hobby knife to set the corner, then round it with 2000-grit paper — rounding reduces cracking risk.
• Tight gaps: wrap fine sandpaper around a toothpick to sand inside narrow gaps, or use 502 glue + baby powder to fill height differences, then sand smooth.

04 · Pre-Installation Checks

• Dry fit test — place the lens in the body shell position and check the edge aligns with the body lines.
• Check for interference — confirm the lens edge will not obstruct other parts such as wiper arms or hood latches.
• Light transmission check — shine a flashlight from inside to confirm no thick flash affects clarity.
• Flatness check — watch for warping after placement; light sanding may be needed.

05 · Common Problems and Solutions

06 · Tools and Materials Checklist

Build. Detail. Inspire. — Alpha Model Technical Team