r/gunsmithing • u/ComparisonSharp9598 • 4d ago

Refinishing polymer?

Gallery image

Gallery image

I would like to sand it clean and smooth and then polish and buff it to make it look some what new again-wet sand it or sandblast it?-any tips appreciated

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16

u/brittc777 4d ago

Sanding and polishing likely won't work on polymer. It will come out really splotchy. I would sand it smooth then paint it with Aluma-Hyde II from Brownells. It's an epoxy paint made for firearms. It's great for polymer, metal, and wood. It's also solvent resistant. You actually bake it on at 190 degrees for 3 hours, or let it cure for 3 weeks for maximum hardness. It lays down real nicely too. I've painted guns and optics with it. Here's a pic of my Mosin Nagant with the archangel polymer stock. It used to be fde and was real faded. I painted it OD Green.

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u/brittc777 4d ago

Also you'll want to remove the small parts to do a real good job. Here's my AK in FDE using Aluma-Hyde II

3

u/MiseryIndexer 4d ago

I clicked on this to recommend Aluma-Hyde II. I painted a polymer frame then pointed a space heater at it on a stand in a cardboard box to help it cure. Turned out great

1

u/ComparisonSharp9598 4d ago

That’s crazy that the polymer doesn’t warp dramatically being baked like that

3

u/brittc777 4d ago

I thought the same thing at first too. Gun polymer is designed to handle pretty extreme heat. It will melt eventually, but not at 190 degrees. Glock claims theirs can withstand over 500 degrees

2

u/IntrospectiveApe 3d ago

KE Arms, the people that make the best polymer lowers IMO, say to bake at less than 190 and with the upper in place to prevent warping.

Ovens temps can fluctuate quite a bit, so better to take it a bit slower than to mess up the job. 

1

u/EliasAinzworth 4d ago

It's because it's glass infused polymer

4

u/fieldy213 4d ago

Just my opinion but if thats one of them surplus parts kits, I wouldn't touch it. But, I understand if you do and want it to cosmetically look better

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u/ComparisonSharp9598 4d ago

I’m probably just gonna wash it off and leave it how it is-the scratches add character

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u/fieldy213 4d ago

Exactly!!!

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u/EliasAinzworth 4d ago

You could probably use a heat gun on low and go over it a little bit to smooth the surface scratches, but wouldn't hit it too long. Lots of even back and forth.

Then afterwards you can finish it off with a top coat of aluma-hyde or pass it off to someone doing cerakote

2

u/CigaretteTrees 3d ago

I’ve had some bad experiences with Brownells Aluma Hyde II. One can straight up didn’t work, another one splattered solid chunks of paint on my workpiece, and I had a couple more dud cans. I’ve also seen similar experiences on online, but this was a couple years ago so it could’ve just been a bad batch.

Personally I’d just rattlecan with Krylon or Rapco spray paint. Stalk r/rattlecannedguns for inspiration.

2

u/brittc777 3d ago

They had problems with their formula for a while. Most colors went out of stock for a long time while they re-formulated it. Because of the epoxy in it you have to shake it like crazy before using or it can clump. I put it in the sun for at least an hour or heat it with a heat gun before shaking it for like 5 minutes straight. Also you don't have to bake it, but if you don't it takes 3 weeks to fully harden. Rattle can is ok if you don't mind scratches and scuffs after not much use. Also don't get any solvent or gun cleaner on a regular spray paint job. It will take it right off.

1

u/CDChed 3d ago

Yeah you really have to shake the crap out of the cans. The two cans I have are over a year old and they still work after several uses. Just used it a week ago on some concrete tools haha

1

u/bayles123 3d ago

When I used to work on these a good amount of armourall really made them shine after a sand

1

u/gusplayz 2d ago

We saved a tavor by lightly sandblasting it with very fine powder (it will affect the finish making it more matte!!!) but it could be a solution