Wednesday 10 April 2024

Resin kit learnings

Resin Kit Learnings

I have built a few of these kits and used resin detailed parts that I have cast or bought. I find these equally as challenging as any scratch built projects I have completed. There are some beautiful kits out there. I recommend that you start by buying one of these at a swap meet and put it together it will increase your modeling skill and problem solving. If you are not happy then you buy another and learn from that. These skills will build your confidence for when you want to scratch build an item.

 As some of you may know there can be some special challenges that are unique to resin. There are different types of resin you may want to know about.  I will go over how to to fix some problems that may come up with kit parts. I will cover the different types of glues that can be used. There are also steps to prep the resin for painting and additional things that have to be done when painting. 

Resin kits are created because they are cheaper to produce.  They do not require the expensive molds that are needed for injection molding and they can be produced in smaller runs. A lot of these kits would never be produced as injection molded kits. So they are special in this way. As with ALL kits it is very important to read all the instruction carefully then read all the instruction carefully again. You need to handle the parts with more care than injected molded kits as the parts can be brittle and will break if too much force is applied. Resin is easy to file, drill and even tap. They will also be covered in mold release which is used so the rubber molds do not get damaged when removing parts. This extends the life of the rubber molds. I will cover mold release later. 

The more modern kits use what we will call white resin, while some of the older kits were made using a yellow resin that is more brittle and harder to work with. If you are just starting out I would stay away from the yellow ones unless you get them really cheap and use them to learn on but maybe not keep in the end.

You will also may come across parts that have weak spots caused by air bubbles or are slightly warped and have flash that need to be removed. The directions will  instruct you on how to handle this. The parts need to be checked for flash and this can be filed away. When you come across a part that has a thin spot on the back that looks almost opaque or is a hole this doesn't mean the part can't be used. I use autobody filler to fill and reinforce these spots just gently apply it so you do not push it through to the front. Let it dry and sand it smooth. If you come across a part that is warped which usually happens on larger parts like walls or longer pieces then this can be fixed by using a hair dryer or a heat gun. You need a perfectly flat surface to lay the part on.  I use the glass that is on the top of my bench. Lay the part on the glass and evenly heat it with the hairdryer. As it gets hotter it will start to lay flat. Once you think it is flat place something on top of it to hold it down while it cools. This will work about 90% of the time. If it is a thicker part or it is being stubborn I will use the heat gun. You can also place the part in water that is 100C for 2-3 min. Then take it out and lay it flat. Once it has cooled it should hold it's shape. Of course that is not a hundred percent foolproof  as you can see below.  I bought this car  at a swap meet. Then the roof bent up in the middle. It had been heated 3 times both the frame and the roof. I was keeping it just as reference to scratch build a new one someday. 

It is now in the garbage some things just can't be fixed. This rarely happens so do not let it stop you from buying any of the resin kits that are out there.

Here is a picture of a Sylvan CN caboose model built from a kit that some have thought was a brass model. That was an oh baby I got it moment. The one stack has a small tilt from handeling

Mold release is like spraying Pam or silicone on your hands.  It will impede your glueing and painting so you must wash the parts first to remove the mold release.  This is a process you should be doing with all your kits no matter what they are made from. You can use  dish soap or  hand cleaner.  I use an old toothbrush to scrub it clean and then rinse it and allow it to air dry. 
For glueing you do not have many choices AC and epoxy glues are about the only ones that work reliably. AC is fast but epoxy is stronger.  

Now you have it put together and are ready to paint. You should, as with all projects inspect it for fingerprints and oil from your hands and spot clean those areas and let it dry. You just have to be careful with the details. You can chose the type of paint you want to use. I have used acrylic, lacquer and enamel based paints from different companies and all work well.

   Have Fun