Short Track Models
Construction Topics => Tips-tricks => Topic started by: David Bogard on August 28, 2018, 05:13:34 PM
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Whenever you purchase a resin body or other parts for your model building, always try to find out what type of resin is used to make the item. That has a great bearing on what you use to clean or work with the piece. A good example would be Big Donkey Resins. Larry produces some terrific stuff for us modelers and let's say you purchased a body from Big Donkey and then as you do with your styrene kits, you give the new resin body a good soap and water scrubbing. Big No-No!! NEVER use any water or soap on Big Donkey Resin. Larry, like many, uses a Polyurethane Resin and water might/can re-activate the resin, giving you some areas that will be sticky, tacky and "gooey" and that will NEVER harden again.
Lacquer thinner, acetone, or alcohol will not harm the resin piece as long as you don't soak it in it. Just wipe your new parts, sand, wipe again and prime. I use Tamiya grey primer. I have tried a half dozen other primers and found that it works best for me.
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Great to know David... I never knew this before. Thanks for the tip.
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....Interesting you bring this up......I both pour and purchase resin parts and pieces.....
There are only a very few resin suppliers in the world.....I choose to use Alumilite products exclusively since that's what I was taught with and have learned on.
With Alumilite resin its perfectly o.k to wash with soap and water as there is no adverse effects from doing so....just don't use scalding hot ,boiling water as it will cause warpage.
A rule of thumb as far as if a resin piece, whether its a body or a small carburetor, needs to be cleaned is to clean it irregardless. Clean the piece either as David has described or with soap and water...I use Dawn dish washing soap. Before ordering any resin parts ,inquire from the dealer on how to clean/prep their pieces before assembly.
Go ahead and treat it like you would any kit piece as far as prep and paint goes....as an example the pieces that I got from Big Donkey where ready for color paint as I received them but I cleaned them none the less. The oil is not a by product of the 2 part resin but rather from the master mold its self. What happens is the resin piece will absorb some of the oils from the RTV Silicone rubber mold during the curing process. Any good resin pourer always uses a mold release or similar product to help preserve the rubber mold and help keep the oils from seeping out and into the resin pieces.
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Thanks for posting this tip David,
I have experienced this problem on some tires and also on one body.
I had a body I shortened and narrowed. I sanded it at the seams and then washed it with soap and water.
It felt completely dry after one day. Then I applied primer and it wrinkled at the seams. I contacted Larry and he told me the same thing you stated above, No soap or water. He recommended alcohol to clean the parts. I've been just wiping down the resin with alcohol now and have had no problems.
Bob
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David,
I too asked Larry what to use for his resin parts, and got the same answer you did.
Just have not gotten around to buying acetone....have yet to find 96%(?) alcohol yet....all I've seen is 70%. so maybe not looking in the right stores.....
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...Try looking for nail polish remover....I believe it is the higher % content .....
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Thanks Brian
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Most chain drugstores carry 91% isopropyl alcohol. Sam's wholesale has a three bottle package for a very reasonable price.
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Thanks, Rick