Acids for removing oxididation?

I was reading about metal oxidation recently (black oxidation spots on some of the restos I'm undertaking are my nemesis, not rust. I want them gone and don't want to sand them out) and came across a few places that said that specifically hydrochloric and oxalic acids chemically react with oxidation on steel essentially neutralizing it and cleaning it off.

Has anyone tried this? Josh Earl is purposely acid etching some of his blades which from the photos seems to GIVE an patterned oxidized look. I want no oxidation. I think I can get some oxalic acid easily but want to know if it could really be the wipe on wipe off oxidizer remover.

I have some old wedges that I can polish to a mirror shine on the buffer or in the corn cob with chrome ox, but as many of you are familiar, no matter how utterly polished and mirror I can get those blades, there are still the black, gun metal gray random "splashes" of oxidation that won't go away.

Any thoughts before I start to experiment?

Chris L

I've used oxalic on bicycle parts and it works like a charm. Its not the same as razor steel, but it worked for me in that situation.

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Originally Posted by BigMallard

I've used oxalic on bicycle parts and it works like a charm. Its not the same as razor steel, but it worked for me in that situation.

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I know it's also used to get the grime off wood (decks and such). Did you use it "full strength" on the bike parts? Did you just wipe it on and off rather than soak it in the acid?

Chris L

I used the recommended strength and soaked them for five minutes. Most of the parts were chromed steel, I don't know how it would react with the steel in the razors. I guess that a 5.00 eBay or garage sale find is in store for this experiment

I'll be interested to see how this works. I seem to remember some guys using rust-removal products to produce an etch on carbon steel, so it might have some unexpected effects. Experiments are fun. :)

Josh

I was shown a technique for etching from a guy named Dave Martell. He owns a sharpening business that specializes in Japanese steeled and styled knives. He uses an etching solution that can be found at Radio Shack, and has awesome results on high-end Damascus knives.

Here is the website.

http://www.japaneseknifesharpening.c...edamascus.html

Sorry to get off topic.

Quote:

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Originally Posted by BigMallard

I was shown a technique for etching from a guy named Dave Martell. He owns a sharpening business that specializes in Japanese steeled and styled knives. He uses an etching solution that can be found at Radio Shack, and has awesome results on high-end Damascus knives.

Here is the website.

http://www.japaneseknifesharpening.c...edamascus.html

Sorry to get off topic.

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Any chance you know what solution from radio shack he uses?

It is called Printed Circuit Board(PCB) Etchant Solution. It is diluted 50/50 with white vinegar. Be sure to add the etchant to the vinegar. If not, there is the possibility of a "splash-out" which can be extremely harmful.

Oxylic Acid should be great for razors. Its really a very mild acid so it should not harm the razor but if there is any writing on the blade I don't know about that. I would certainly do a dry run with a junk razor though.

Light black spots usually come off with a pencil eraser and I have gotten them off easily and completely with a dremmel so we must not be talking typical black spots but true corrosion or something else.

OK, update here. Well.....er, ahhhh....DON'T use Oxalic acid on razors unless you want to oxidize and etch the daylights out of them.

Report:

I bought some powdered Oxalic at Ace Hardware because it's a few blocks from my work. I grabbed a descaled J.A. Henckels approx 6/8-7/8 old wedge #22 that had horn scales and mixed some of the powder with water. I was conservative in using a fairly small amount of powder, but I didn't get a scale out and was not scientific in my measurements.

I wore thick rubber gloves and dabbed a bit of the acid solution on a clean rag and started to rub at oxidation spots. It seemed to lighten the oxidation spots ever so slightly, or it could have been my imagination. The overall surface of the faces of the blade DID seem to become brighter, but I could have hocked a loogie or wiped some sweat on the rag and it would have done the same darn thing.

So.........I decided I would let the blade sit in the solution for less than five minutes whilst I went to brush my teeth prior to turning in. I was literally gone less than five minutes only to come back and find a very nicely uniformed dark gray oxidized blade.:rant: The only way that's coming off is sanding; which is not a big deal since that's really been my "Plan A" for this blade anyway.

Then, I proceeded to email Bill Ellis who I've corresponded with on prior occasions to ask him what if anything he has found to easily do away with deeper oxidation (not surface stuff that Maas/Flitz/erasers/Naval Jelly takes off). He said in all the years he's worked with steel he has NEVER found a magic bullet for easily taking off significant oxidation other than sanding. He's got a great sense of humor that I enjoy very much; after I told him what happened to my experimental blade the first thing he wrote back was: "But now you don't have the oxidation spots on the blade anymore, do you?";)

So.....this did not work for me.

Chris L

Quote:

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Originally Posted by BigMallard

It is called Printed Circuit Board(PCB) Etchant Solution. It is diluted 50/50 with white vinegar. Be sure to add the etchant to the vinegar. If not, there is the possibility of a "splash-out" which can be extremely harmful.

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Any ideas on how long you leave the blade in the etching solution??

Its trial and error. Different metals are going to react differently to the solution. I'd try rubbing it on at first and see how that goes, if you think it needs a soak, start with 1-2 minutes, then go from there. I'm neither a metallurgist, nor a chemist, so I have to do things by trial and error much like most of us here do.

For me I try things on beater blades I get off of eBay, or through flea markets. If I mess it up, I'm out 5-15, depending on whether the scales are worth keeping or not. I've been able to translate some of the things that I know about firearms restoration and knife refinishing to straights, but a lot of the stuff I've learned has come from experience. It is a bitch as a teacher, but the lessons are well learned.

If your going to use oxylic acid you need to be very careful about the concentration. Anotherwords you need to use a very dilute solution like a couple percent. The idea is to attack the major rust on the blade and not mess with the oxide that exists throughout the blade in general. You can't see it but its there. Also oxylic acid will clean all the oxide off but will not polish the metal so if your not careful you can be left with a surface free of oxide and nothing where the oxide was.Also after using the stuff you need to polish the blade like when you use these soak in silver cleaners that will remove all the tarnish off the silver but leave a dull matt finish which then has to be polished.And remember the stuff is acid so...