Corrosive Krylon?

[Bob the Angry Potato]

Anyways, I recently picked up an HFC HSC (PPK), and it had some marks on the top of the barrel I wanted to get rid of.

My friend volunteered to paint it with some Krylon Flat Camo paint, which we put some over it. However, it didn't stick to the top- and instead, dripped to the bottom. When we got back about an hour and a half later, the finish had been completely ruined- it seemed that the paint itself had melted the plastic into an ugly, misshappen mess, and when we took it off it seemed to be taking off layers of the plastic too.

Any way to remedy this, at least, and any insight into what may be causing it?

[The Gopher]

It's screwed.

 

I reckon the paint has petroleum distilates. That eats plastic, most paints, rubber, and organic substances to an extent.

 

Once the plastic is "melted" or "disolved" it's a goner. Pics?

[Wege]

That aint on.

I have used Krylon many times on plastic/abs items.. and the ONLY times I have seen an issue with dribbly stuff.. has been when I have painted/sprayed the item far too close, and with too much paint.

[Bob the Angry Potato]

It's screwed.

 

I reckon the paint has petroleum distilates. That eats plastic, most paints, rubber, and organic substances to an extent.

 

Once the plastic is "melted" or "disolved" it's a goner. Pics?

 

It worked on his TM Sig 552 with no problems- it's Krylon Camoflauge, which supposedly works on most paints (that's what it says).

 

I'll get pictures up when I can, but it looks pretty much screwed. Would epoxy over it work?

[Tom Andrews]

Using a cellulose based paint is sometimes risky on plastoc. It very much depends on the type of plastic and the constituents in the paint. Also putting a slightly too thick a coat on can cause the top of the paint to dry, but underneath stay wet, dissolving the plastic.

 

Either use acrylic or very thin coats on plastic.

To try to get a reasonable surface back I suggest leaving the damaged part for at least a week for the plastic to stabilise, then sand down with fine wet and dry sanding paper used wet with a drop of washing up liquid.

 

If you stick the wet and dry to lolly sticks or flat pieces of plastic you can stand a better chance of getting a reasonable finish.

[Bob the Angry Potato]

Here's pictures. The bottom is pretty much screwed out of all recognition, I don't think I want to sand it any further. Thanks, though- when it dries, perhaps a coat of epoxy would do it some good.

 

Paint used-

 

Gun itself-

 

Any other ideas? I've never used epoxy before, I'm afraid.

[Tom Andrews]

That is bad, far worse than I would have expected. Its worth trying some car body filler in that - can't make it worse! Something like Plastic Padding which comes in small tubes is good. There is also Milliput, which is epoxy two part filler/sculpting material. Personally as its not structural, I'd try PP, and sand it down as previously described. Then coats of Tamiya acrylic model paint.

 

 

[Bob the Angry Potato]

That is bad, far worse than I would have expected. Its worth trying some car body filler in that - can't make it worse! Something like Plastic Padding which comes in small tubes is good. There is also Milliput, which is epoxy two part filler/sculpting material. Personally as its not structural, I'd try PP, and sand it down as previously described. Then coats of Tamiya acrylic model paint.

 

Right on, many thanks to you. Will head down to Canadian Tire later on, to pick some up.

I'm a bit peeved, this gun (while cheap) isn't exactly very common in the Great White North.

 

EDIT- after a bit of searching, seems that Plastic Padding isn't readily available in Canada, mainly just the UK. Any other suggestions? There's a lot of different sorts of auto-body filler at the local hardware store, at least.

[Raven12]

your hardware store should stock Epoxy repair putty. its very simple to use and would do the job.

[Burke]

Ive spray painted lots before and it looks more like just paint bubbles than melted palstic to me. But then again the pics are blurry. Thats crazy tho if it actually melted the plastic. Are you sure it isnt just massive overspray? If it was massive over spray you could take arag and wipe it all down and let the under coat dry then sand and refinsh.

[Bob the Angry Potato]

Ive spray painted lots before and it looks more like just paint bubbles than melted palstic to me. But then again the pics are blurry. Thats crazy tho if it actually melted the plastic. Are you sure it isnt just massive overspray? If it was massive over spray you could take arag and wipe it all down and let the under coat dry then sand and refinsh.

 

Definately melted. There's a hole where some of the paint used to be, that's a few millimetres deep.

My friend painted it, it was simply on top but some of the paint must've dripped down and built up under the barrel.

[Senor Bear]

And this is why the cans say something along the lines of: if using on plastic test on a small/insignificant area first.

To cover their own behinds of course.

[Tom Andrews]

your hardware store should stock Epoxy repair putty. its very simple to use and would do the job.

 

Epoxy putty isn't the best stuff for the job, simply because its harder than plastic. When the repair is rubbed down the softer plastic gets removed faster than the epoxy putty.

 

Its fine for structural repairs, but not cosmetic.

 

I believe its called Bondo in the States and Canada, also 'wing in a tin' 'instant wing' 'gloop' and several other names............

[Magsz]

It's screwed.

 

I reckon the paint has petroleum distilates. That eats plastic, most paints, rubber, and organic substances to an extent.

 

Once the plastic is "melted" or "disolved" it's a goner. Pics?

 

Petroleum distillates generally dont corrode plastic on contact, at least the ones commonly found in household silicon products and spraypaints.

 

Something else was in that paint that caused that.

[Stealthbomber]

That gun must be made of some really awful quality plastic.

 

I've used Krylon on lots of plastic stuff with no issues. The stock of my L96 springs to mind as the biggest thing but I've also done plastic pistol slides as well. How odd!

 

To fix the gun I'd recommend filling the holes with JB Weld or Plastic Padding Liquid Metal.

To be pedantic, if you can find it, look for the small tubes of Liquid Metal. JB Weld and the larger tubes of Liquid Metal sry in a sort of dark grey colour. The small tubes of Liquid Metal dry in a perfect black so, if you're careful, you'll be able to fill the holes and then give the repair a rub with fine wet & dry and, hopefully, not need to paint it.

[Bob the Angry Potato]

That gun must be made of some really awful quality plastic.

 

I've used Krylon on lots of plastic stuff with no issues. The stock of my L96 springs to mind as the biggest thing but I've also done plastic pistol slides as well. How odd!

 

To fix the gun I'd recommend filling the holes with JB Weld or Plastic Padding Liquid Metal.

To be pedantic, if you can find it, look for the small tubes of Liquid Metal. JB Weld and the larger tubes of Liquid Metal sry in a sort of dark grey colour. The small tubes of Liquid Metal dry in a perfect black so, if you're careful, you'll be able to fill the holes and then give the repair a rub with fine wet & dry and, hopefully, not need to paint it.

 

Righto, I'll do my best to look tomorrow.

I'm quite used to Western Arms quality guns, I bought this to be a useable sidearm which I won't panic after it falls out of my incredibly low-quality yet overpriced holster. The gun itself performs far better then I thought it would, but perhaps the quality of the plastic is somewhat questionable.

 

Thanks for that, Canadian Tire is open late on Saturdays.

[gambon]

"Krylon paint is a No Prep Paint the Slightly Melts the Vinyl on application so becomes part of the Surface on full curing."

sounds like was sprayed with to heavy a hand ,or the can was not warn/shaken enough....so

 

leave your plastic to reharden as mentioned above,then do NOT use a hard epoxy like liquid metal,us a soft filler eg milliput or softer in very thin layers ,leaving each layer to dry fully until the surface is proud of the adjacent good areas of plastic,then use 1500 grit wet and dry ,very gently smooth the milli put back and refine the shape,always leaving to fully cure in between,good luck chap should be ok

 

[Senor Bear]

"Krylon paint is a No Prep Paint the Slightly Melts the Vinyl on application so becomes part of the Surface on full curing."

sounds like was sprayed with to heavy a hand ,or the can was not warn/shaken enough....so

 

Ah theres a point, if the can wasn't shaken properly (if at all), then the chemical components of the paint would not mix, meaning you spray the heavier chemical from the can first, which is probably the solvent in this case as the plastic ended up being dissolved.

Correct me if I am wrong this is just my theory.

[Phatvortex]

I'm going to have to say- it was probably user error. You just simply can't spray in one thick layer.

[Bob the Angry Potato]

I'm going to have to say- it was probably user error. You just simply can't spray in one thick layer.

 

Yeah, I think it was.

He sprayed on WAY too many layers for our own good, it was simply on top but it dripped down. It was shaken a LOT beforehand though- I didn't pay too much attention to it at the time as he's painted quite a bit before.

 

Either way, thanks for all the advice- after Remembrance Day I'll have to get some epoxy and paint.

[Chris North]

How bad did it look before you tried to remove the paint? Is it possible that it was just some really bad paint drippage and when you tried to clean it up you made it worse?

 

The plastic on these things seem to be really bad when it comes to resisting chemicals. I once tried *mumbling noises* with acetone on my HFC .25, but the plastic became soft and started to melt a lot faster than the paint would. The HSC is pretty much the same thing as the M1908 in a different package.