Anyone know how to get these dark stains out of DLC?

DrunkenMaster · May 10, 2018

I opened up a bag of this expanding foam stuff for fence posts. It comes out in a liquid then quickly hardens. Anyways, it's pretty nasty stuff and I got it all over my blade.

I scraped all the residue off the blade and then scrubbed it with soap, alcohol, and wd-40 but I can't seem to get rid of the stains it left on the DLC.

I've seen these kind of stains before on DLC, but im not really sure what causes them or how to remove them (if you can). Anyone have any ideas/tips?

(sorry for the large pictures, I was having trouble resizing them on imgur)

palmerdl · May 11, 2018

Don't know for sure, but I would try acetone ( fingernail polish remover ). After that I would try a Magic Eraser or Barkeepers Friend, both are very fine abrasives, but I don't know if they would affect the DLC coating... assuming you want to keep it intact.

anthonycastorena2014 · May 11, 2018

Try breakfree CLP and one of your girlfriend’s/ wife’s makeup sponges. It will more than likely work. If that doesn’t work try goo gone.

DrunkenMaster · May 11, 2018

Thanks for the suggestions fellas, I have a few more things to try now!

Obsessed with Edges · May 11, 2018

Looking at online descriptions of the stuff (I'm looking at a brand called 'Sika' at Home Depot), it's described as a polyurethane resin. Maybe similar to epoxy-based materials. If so, the acetone may have the best chance to clean it up, or another fairly strong solvent-based cleaner (mineral spirits, etc). If it's anything like epoxy, the milder cleaners may not do much. The instructions for the Sika mix mention it's not removable with anything besides some sort of scraping tool, after it's cured.

Edited to add:
If acetone is the key, it may be worth using the regular, full-strength stuff. I'd recently picked a bottle of fingernail polish remover, and it's formulation these days is pretty watered down, it seems. Much weaker as a cleaner for stuff like epoxy.

The 'Goof-Off' brand of cleaners also makes an acetone-based cleaner for super glues and epoxies, and it's pretty strong. I used it to clean up residual epoxy used in repairing a Fallkniven DC4 hone, after it's diamond plate separated from the ceramic side.

l1ranger · May 11, 2018

Obsessed with Edges said:
Looking at online descriptions of the stuff (I'm looking at a brand called 'Sika' at Home Depot), it's described as a polyurethane resin. Maybe similar to epoxy-based materials. If so, the acetone may have the best chance to clean it up, or another fairly strong solvent-based cleaner (mineral spirits, etc). If it's anything like epoxy, the milder cleaners may not do much. The instructions for the Sika mix mention it's not removable with anything besides some sort of scraping tool, after it's cured.

pretty much what i was going to say - i would start with acetone and work up to mineral spirits, turps, naptha, etc.

and next time, use stone and/or concrete for posts like you are suppossed to

DrunkenMaster · May 11, 2018

l1ranger said:
pretty much what i was going to say - i would start with acetone and work up to mineral spirits, turps, naptha, etc.

and next time, use stone and/or concrete for posts like you are suppossed to

Lol, I was helping someone else fix a broken fence section and post ( I swear I swear). It actually worked okay for just replacing one post and doing a quick repair. Way too expensive and flimsy to do a whole fence with it though.

And thanks everyone, going to try acetone and see what happens.

Alberta Ed · May 11, 2018

Thanks, let us know how that turns out.

Bill DeShivs · May 11, 2018

You are probably going to have to soak the blade in acetone. Polyurethane is sticky stuff, and the blade is satin finished-this gives the goo lots of contact surface. It looks like what's left of it is in the surface "pores."

DrunkenMaster · May 11, 2018

Bill DeShivs said:
You are probably going to have to soak the blade in acetone. Polyurethane is sticky stuff, and the blade is satin finished-this gives the goo lots of contact surface. It looks like what's left of it is in the surface "pores."

How long would you recommend soaking it for?

l1ranger · May 11, 2018

i'd start with 5 minutes and work up from there.

I'd be wary to keep the pivot and handle out of the solvent as well - not sure what that might do to it

DrunkenMaster · May 11, 2018

So here's the finished product. Soaked the blade in acetone for about an hour, and then scrubbed each side with Bar keepers Friend and a slightly abrasive sponge. I probably could have kept going with the bar keepers friend, but I was worried I'd take off too much of the coating.

Still some left over traces of the stuff, but overall I'm very happy with how it turned out, thank you to everyone who chimed in! Cheers.