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Discussion Starter #1
My friend is building a resin garage kit of Bloefelds Bathosub from "Diamonds are Forever"

He is having paint issues.

He washed the kit with soap and water, let it dry overnight, then primed with Tamiya grey primer.
Let is sit overnight, then painted with Tamiya Racing white (spray can).

The paint took hours to dry and pooled badly.



Thinking it was not fully cleaned he stripped everything, rewashed, and repeated.

3 times, He had the same results.

After the 3rd time he decided to try brush painting it using Mr primer. It is now pooling.

I'm out of ideas.

The paint is good, he test sprayed some sheet styrene.

The only thing we can come up with is the resin is not fully cured, Though it does not feel soft.

He asked me to post here and ask, So..

Does anyone have any ideas what is going on?

Thanks
 

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Does he know what type of resin the kit is made from?

What is his technique - several layered coats or one overall coverage.

If layered what is his dry time between coats.
 

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Discussion Starter #4
Thanks for the help.

It's white resin from Larson production. Both of us have built his kits before with no issue.

He put down 2 thinish coats primer. He says the white paint coat was not thick on the 1st attempt and got thinner with each other attempt. The last attempt was brushing on Gunze Mr. Primer surface prep.

As I said between each all the paint and primer was removed and the resin was re washed.
 

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After three times washing and painting I cant image it being a mold release issue. And it sounds like he dried it long enough for the water to evaporate. Maybe try an alcohol wipe down and then painting.

He may also try doubling the dry time between primer coats and adding more lighter coats - maybe it was to thin.

Another trick is move farther away from the object being painted. The paint may not have had time to separate from the propellant and that is the source of contamination.

I also understanding the primer is a spray can as well?
 

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the resin is still leaching.
soak it in Bleche White for an hour or so and then wash it off with dish soap.
Yup. I’ve had this same problem with a few resin kits. You could also try soaking it in Purple Power overnight, but he may just have to let it sit for a while.
 

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I'd suggest acetone. Should remove anything there, and then evaporate completely and leave no residue itself.

Though if it is leaching due to an improper mix ratio when the resin was poured, there's really no fix for that. It'll never cure properly. Only solution there is replacement.
 

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I was wondering what the resin would be leaching still? I know there are different kinds, but is it a fluid or a gas? Does the paint bring it out? Is it the release agent that soaked into the resin?

And yes if it is still a problem - then replacement seems to be the only alternative.
 

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some brands of resin have an ingredient that leaches out as a liquid over long periods of time. I don't recall which.
but, I have painted resin bodies that I thought were clean and months later the paint started lifting on them.
again, I don't recall which brand or who I bought the bodies from.
 

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I was wondering what the resin would be leaching still? I know there are different kinds, but is it a fluid or a gas? Does the paint bring it out? Is it the release agent that soaked into the resin?
Many resins will eventually cure on their own, even without being mixed. When they are produced, an inhibitor is mixed with the resin, and the curing/activator/hardener part that is mixed in for use renders that inhibitor inactive, which in turn allows the resin to cure. Given enough time, these types of resins will cure on their own, even unmixed or with a less than ideal (not enough hardener) mix ratio. That could take months or years though.

Other types of resins work the other way, and the hardener itself is necessary to trigger the reaction that causes the resin to solidify. Incorrect mix ratios will cause either lack of curing, or incomplete curing.

Regardless of type, continued leaching of liquid or outgassing from the resin is indicative of improper mixing (incorrect ratio or insufficient blending of the two parts) and of continuing chemical processes that indicate the resin is not fully cured.* (I suppose it's possible in some cases, excess hardener might continue to leach from the resin after curing, but even in this unlikely case, we're back to improper mixing).

Long and short of it: Properly mixed resin will not offgas or leach material after it is cured, because there is nothing left to leach out or offgas - it was all consumed in the initial curing reaction and chemical reactions have ceased.

If a supposedly cured part is leaching or outgassing, there's no fixing it**, and replacement is the only practical remedy available.

If an acetone bath and acetone wash (followed by an air dry) doesn't work, I'd contact the kit manufacturer about a replacement.

* This is simplified, as some microscopic level of curing and reactions will continue nearly "forever" even in properly mixed resins, but it won't be enough to cause problems.

** Unless it's one of the preinhibited types (the manufacturer of the resin itself could answer that), but a full cure could literally take a year or so, depending on the specifics.
 
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