By Gerhard van Vuuren.
Resin kits, a word some of you might know and some not, so I will give a short intro on them. Resin kits are model kits not made from the normal injection moulded Polystyrene by mainstream plastic model companies like Revell, but kits cast by hand in Polyurethane resin in rubber moulds, mostly by aftermarket companies operated by one or more model enthusiasts, mostly on a part time basis. These kits are of subjects not available in plastic and are mostly some of the less popular, more obscure or custom subjects. In resin you will be able to get a 4 door 1967 Impala or station wagon where in plastic you only get the top line 2 door 1967 Impala SS Sport Coupe. Resin kit can be divided into two main groups namely:
- Complete kits – All parts needed to finish the model included.
- Conversion kits – Where the necessary body and other parts to build the specific model is included, but you need a donor plastic kit for parts like chassis, wheels, tyres etc.
In this article I’m going to use a conversion to ease you into the resin scene as it is fairly simple and basic. The kit I’m using is the 1961 Ford Falcon Courier (Sedan delivery) by Jimmy Flintstone Studios in the USA. There are only 3 resin parts namely a body, interior tub and load bay floor insert (Fig 1).
The donor kit for this build is the AMT 1961 Ranchero (Fig 2), which donates the chassis, dashboard, steering wheel and column, windscreen glass, front bumper and grille, rear bumper, rear lights and small interior parts like the shifter (Fig 3). As the resin body’s hood is moulded closed, I will build it as a curb side (no engine) model.
Preparation of the resin parts
This is the most important step in a resin build. The reason being that a mould release agent is applied in the moulds before casting, and the finished parts are covered by a thin film of this greasy stuff. If it is not removed properly, your paint won’t stick and you will get fisheyes and lifting and peeling paint all over the show. First, I wiped down all surfaces of the resin parts with a cotton (old T Shirt) rag soaked with Industrial Alcohol. After that, I soaked all the parts in some engine cleaner for 30 minutes and rinsed them with running tap water. Finally, I scrubbed the parts with a toothbrush and a 50/50 mix of Handy Andy and Sunlight Liquid, rinsing with running tap water afterwards. I put the parts outside and left them to air dry. Do not leave the resin parts in direct sunlight as the resin can soften and warp out of shape when exposed to excessive heat.
Prepping for paint
After the parts have dried completely, I gave everything a few coats of Tamiya fine grey primer which enabled me to detect any flaws or damage in the surface that had to be fixed. There were a few scratches in the resin which I filled with correcting fluid (Tippex) and then sanded smooth. You will notice that the window openings are filled with “skins” of resin. I leave them in place until I’m happy that the prep work on the body is finalised before they are removed as they help to reinforce fragile parts like the quarter window posts. Fig 4 shows the paint prepped body sanded smooth with all imperfections filled. Now we can start removing the unwanted webbing in the window openings using a sharp fresh blade in a model knife (Fig 5). After all the unwanted resin is removed from the openings, you can finish the openings to obtain a smooth even sedge with a emery board or similar tool (Fig 6). The body I was using had some heavy flash on the edges of the rear fender openings. This happens when the moulds get worn out and resin oozes in between the mould halves which used to seal against each other but don’t do so anymore.
I cut away the bulk of the flash away carefully with a side cutter after which I carefully and slowly trimmed away the rest with my hobby knife (Fig 7). After the fenders were cleaned up, I finessed the edges with some 1000 grit sandpaper, ending with the clean and correct shaped fender edges as can be seen in Fig 8. The body was now in ship shape condition and ready for the paint process as seen in Fig 9.
Test fitting the chassis
I slipped the chassis under the body and surprise surprise, the wheels both front and rear sat too far forward in the wheel arches and not in the centres as it’s supposed to. I trimmed off the locating pegs on the chassis that fit in corresponding holes in the rear of the body in order to move the chassis a bit back to get the wheels to centre in the wheel arches, but they were still sitting too far forward. Luckily this is not a real car and a hobby knife and a motor tool with a grinding bit can do wonders. I cut away 2mm’s at the rear of the chassis pan and rounded the corners so that I could slide the chassis further back in the body.
In Fig 10, the standard chassis can be seen at the top and the modified one at the bottom with the shortened rear edge indicated by the arrow. I inserted the axles and attached the wheels and test fitted the chassis again and this time the fit was perfect and the wheels centred in the arches (Fig 11). Now we are ready to paint and assemble which I will cover in next month’s article.