Why do resin parts need washing?

Resin parts are cast in silicone moulds coated with release agent. This oily residue prevents paint and glue from adhering properly. Soak parts in warm water with washing-up liquid for 15-30 minutes, then scrub gently with an old toothbrush.

What is pinning and why is it needed?

Pinning means drilling holes in mating surfaces and inserting short lengths of brass or steel rod to create a mechanical joint. Resin is heavier than plastic and CA glue alone may not hold. Pinning adds structural strength to the bond.

What diameter brass rod should I use for pinning?

For 1:48 and larger parts, use 0.8-1.0mm brass rod. For 1:72 and smaller, use 0.5-0.7mm. The rod should be about 4mm deep in each part. Use a pin vise with a matching drill bit to make the holes.

Can I use poly cement on resin parts?

No. Poly cement only works on styrene plastic — it dissolves the surface to create a weld. Resin is a different material and poly cement will not bond it. Always use CA (superglue) for resin. Medium viscosity CA is best for most resin joints.

ModelCalcs

Resin Parts Calculator — Aftermarket Prep Planning

Plan resin aftermarket part preparation including washing, pinning and glue quantities.

Number of Resin Parts

Average Part Size

Pinning Required

How We Calculate This

Calculates preparation time, glue and pinning materials needed for resin aftermarket parts.

Formula

Wash time = 15 minutes (standard soak)
Prep time = Parts x Time per part (by size)
Pins needed = Parts x Pinning factor
Brass rod = Pins x 8mm per pin
Total time = Wash + Prep + (Pins x 5 mins per pin)

Frequently Asked Questions

Related Calculators

Parts Count Estimator

Estimate total parts count for a kit based on scale, subject type and complexity.

Glue Amount Calculator

Calculate how much plastic cement or CA glue you need for your kit build.

Filler Calculator

Estimate putty or filler needed for seam lines, gaps and corrections.

Decal Calculator

Plan decal application with setting solution and softener quantities.

Rigging Calculator

Calculate rigging line lengths for biplanes, ships and other rigged models.

Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.