Resin Shrinkage

prisoner_1079 · Post by **prisoner_1079** » Sat Apr 21, 2012 5:53 pm

I was wondering, when designing a master for a resin kit, is it necessary to build the original slightly larger than the ship should be in order to counteract resin shrinkage?

Also, on a related note, if one were to make a kit of something that has multiples of the same part, would it be ok to make a mold of the single piece, then use the resin copies to make a mold with however many copies of the part you need for the kit? Or is it better to just make several individual molds using the original master?

Johnnycrash · Post by **Johnnycrash** » Sat Apr 21, 2012 6:24 pm

prisoner_1079 wrote:I was wondering, when designing a master for a resin kit, is it necessary to build the original slightly larger than the ship should be in order to counteract resin shrinkage?

No, it is not necessary to build the master over-sized. UNLESS, you are looking to cast it in metal. Whole different ball game.

Also, on a related note, if one were to make a kit of something that has multiples of the same part, would it be ok to make a mold of the single piece, then use the resin copies to make a mold with however many copies of the part you need for the kit? Or is it better to just make several individual molds using the original master?

Make one, mold it, cast it, and you are ready to roll. Not necessary to make the same part over and over. If you have a part that has a base shape that is the same, but with left/right handed details added to it; Make the base shape, mold it, cast it, detail it out handed. And you are ready to roll. Again.

The shrinkage on modern resin is very minimal. Some more than others, of course, but usually in the 1% or less range. And for most of the modeling applications, that's not a factor for fit and finish.

prisoner_1079 · Post by **prisoner_1079** » Sun Apr 22, 2012 7:22 pm

Ok cool, thanks for the tips!

aussie muscle · Post by **aussie muscle** » Wed Apr 25, 2012 7:24 pm

or if you use a two-part resin, like body filler, you wont get any shrinkage because the reaction is chemical based, rather than evaporative.

Joseph Osborn · Post by **Joseph Osborn** » Wed Apr 25, 2012 7:36 pm

Shrinkage!

http://www.youtube.com/watch?v=1cUNNKzj_Nc

prisoner_1079 · Post by **prisoner_1079** » Wed Apr 25, 2012 11:22 pm

I knew it was gonna be Seinfeld as soon as I saw the youtube link.

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Resin Shrinkage

Resin Shrinkage

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