Quickest way to clean a resin casting

[Lemosteam]

Going to paint a boatload of Fine N Scale PRR freight cars this weekend, all cast resin.

Would a quick 1 minute dip and swirl in some acetone be OK, and would it remove the pervasive fish-eye in the paint?

I'll be using stinky paint for these.

[mmagliaro]

It's been 100 years since I did one of these, and I did airbrush it with Floquil back in the day.  But I'm sure I didn't need to resort to acetone.  I think just a toothbrush and warm soapy water is all I used and it came out fine.

[thomasjmdavis]

It's been 100 years since I did one of these, and I did airbrush it with Floquil back in the day.  But I'm sure I didn't need to resort to acetone.  I think just a toothbrush and warm soapy water is all I used and it came out fine.

I think that's all I've done, as well.  From the Fine-N-Scale "Modeling Tips" on their website (and instructions for boxcars says the same)-

Resin will accept any kind of model paint, but wash the castings with soap and warm water to remove any mold-release residue that might interfere with the paint, then spray on whatever color you want for the body.

[wazzou]

I think just a toothbrush and warm soapy water is all I used and it came out fine.

Same. 
I've done a few Fine N Scale castings and some of my own castings and Palmolive, warm water and a soft tooth brush worked well.

[Lemosteam]

Thanks guys. I’ve just had so many problems in the past.  Acetone Evans so fast, I don’t think it will damage anything, but I’ll go the Palmolive route.

[nickelplate759]

Does it depend on the resin?   I've used dish detergent and water on Fine-N-Scale and Wheels of Time castings.  If I recall correctly, Skytop Models ( @skytop35  ) recommended washing first in mineral spirts, then detergent, which also worked nicely.

[peteski]

For decades he consensus among the automotive modelers used to be to dip the urethane casting in



to get rid of any silicone mold release.  But I also heard that the "new" (current) version of the product has a changed formula which does not work well.

I suspect any strong degreaser  like


or its cousin


Dollar store


Should also do a good job.  Be careful with these strong degreasers - they contain Lye. Wear gloves.

In my experience, probably 99.99% of resins used for casting models (of any kind) are 2-part Polyurethane (urethane) resinis.  I have seen very few examples of Polyester resins, but those are almost always used for casting clear parts. All the resins I have worked with can be safely exposed to the above chemicals.  But I have heard that when stripping paint from urethane resin castings by using 99% Isopropyl Alcohol, when they are left in it overnight, the resin turns into rubbery goo.

Quick rinse in acetone probably wont hurt them but I wouldn't leave the resin exposed to acetone for loner periods of time.

[thomasjmdavis]

Does it depend on the resin?   I've used dish detergent and water on Fine-N-Scale and Wheels of Time castings.  If I recall correctly, Skytop Models ( @skytop35  ) recommended washing first in mineral spirts, then detergent, which also worked nicely.

I am sure it DOES depend on the resin.  Always go with the manufacturer's recommendation. 

Also, my "go to" detergent is Ajax Ultra dish detergent (it removes grease about as well as Dawn, and seems to me to leave less "soap" behind).  The one caveat to "wash in warm water and dishsoap" is that many dish detergents contain hand lotion or similar additives that may leave their own residue behind. 

[SkipGear]

Warm water soapy bath. I'm afraid of solvents, not knowing exactly what resin was used and how old the castings may be and how they may react. Had an old Camden and Amboy kit self destruct when lacquer thinner touched it.

 Soak in warm water for about 10 minutes in a small bucket/tub/butter bowl, etc. Run warm water in the bucket afterward till soap suds are completely gone. The turbulent warm water is usually enough to take care of anything left after the soap. I've been doing similar to my 3d resin prints after the  requisite alcohol rinses with good results.

[Doc Frankenfield]

it really depends upon the resin that is used. most two art resins are fairly chemical resistant.
the real problem is that resin is cast in silicone molds, which for longevity are usually maintained with a silicone release agent. Regardless of the process, trace amounts of silicone are always present on the surface of a resin casting.
 I recommend alcohol and a good  degreaser. in a pinch, the aforementioned cleaning materials work and you can also use comet and such with a toothbrush.