Building A Resin Kit

by Forrest Cox & Scratchbuilders

Scratchbuilders gets regular inquiries regarding building differences between our kits and injection molded kits. This section provides some insight into building a resin kit; however, there is no substitute for experience. Hopefully this new section will help those who have not tried a resin kit to understand the level of difficulty and modeling enjoyment one might expect.

For our kits the level of detail is only slightly above what is offered in injection molded kits. They do offer an excellent opportunity for super detail modelers to do their stuff on unusual subjects not available elsewhere.

What's the difference between this and an injection molded kit? The biggest differences are the fit, the glue, the weight and the clear parts. I'm sure other differences exist but these are the most prevalent. Here are some tips on how to successfully accomplish these modeling tasks.

Fit:

The biggest challenge for most modelers will be fitting. Our kits don't come with alignment pins or attachment slots. This means that during the construction the kit it must be aligned and fitted together. Wings to fuselage and tail planes to fuselage are the biggest challenges. Wing thickness, canopy attachment and landing gear installations are not quite as hard, some simple techniques can assist you in construction.

Test fit and align each assembly or piece before you glue. This is critical to success. Test fit one piece to the next. Look for slag, or high spots where the parts are touching. Sanding on the inside or end of the part, remove any high spots with sandpaper. Don't sand too much, sand a little and test fit again.

For instance, when matching the wing surfaces together sand any high spots off the internal supporting structure of the wing, not by thinning the upper surface. Match the trailing edge of the wings by thinning the wing surfaces on the inside. Don't sand too much, sand a little and test fit again.

Create sub-assemblies to reduce the possibility of changes causing fit problems. For instance, fit the main wing as a unit, the fuselage as a unit, the tail as a unit. You don't want the addition of cockpit parts to widen the fuselage and cause a fit issue with the upper wing, especially after the wing is glued together.

What you want to carefully consider is things like: Matching upper and lower wing halves and not considering the match between the upper wing and fuselage. Matching the tail to the fuselage without considering the fit of the wing to the fuselage.

A two steps forward and one step back approach will assist you. For example, when you get the wing surfaces matched, tape them into place with masking tape and fit the fuselage assembly. When the fuselage is fitted then remove it, take a step back and glue the wing surfaces together. Then tape the fuselage to the wing, align the tail, remove the tail and glue the fuselage. I'm sure you get the idea.

Resin parts can be heated in water and straightened just like injected molded parts. If you don't want to hassle with that our replacement policy will replace any part free of charge.

Every kit is different but the same challenges are faced in all of them. If you are new to resin, the P-40 kit is a great way to start. It's simple, comparatively inexpensive and has a number of challenges to practice these skills. Not only that, it makes a great looking early version P-40.

Glue:

As with any resin kit instant glue or epoxy is needed for assembling resin and white metal parts. All clear parts are made of Zivac, epoxy or white glue are recommended, instant glue may cause clouding of clear parts as it dries. Roughing the mating surfaces will help the glue to bond.

Weight:

Our kits are hollow cast so the weight is held to a minimum. This is traditionally a problem with resin kits in that solid castings are very heavy. Our landing gear struts are white metal with steel inserts when needed. We recommend displaying your kit on a rough surface such as paper or cardboard. Polished flat surfaces such as glass place a high side load on the landing gear because the tire can't grip the surface.

Clear parts:

Clear parts are all vacuform pieces. The biggest challenge here is fitting the parts. Single piece cockpits can be fitted with a cylinder of fuselage size wrapped with sandpaper. In some kits, such as the Me109 B/C/D the canopy has flat contact surfaces with the fuselage and can be fitted with a flat sanding board. The Me410 kit has a split canopy that must be glued together along canopy seams. This canopy can be aligned by drilling small holes at corner joints and temporarily inserting guide pins. We don't supply extra canopies in the kits but don't be concerned, replacements are available free of charge.

On occasion instant glue can be used successfully in very small amounts to tack a canopy in place in three or four places. Then add the white glue mixed with water to finish off the seams.

© Scratchbuilders 2002