How to remove discoloration from heat?

[toofazt]

I need to figure out how to remove the discoloration the heat from welding stainless steel produces. I'm using 20GA brushed or mirror finish so I need a solution that doesn't involve abrasives, etc. Possibly an acid I could immerse the part in? Pictures below showing the blue/gold color. Thanks for any help!

[welding101]

passivation

passivation is the removal of exogenous iron or iron compounds from the surface of stainless steel by means of a chemical dissolution,most typically by a treatment with an acid solution that will remove the surface contamination but will not affect the stainless steel parts where i work we have a machine that we ground to the welded part then there is a hand held part that you slide a sock type cotton over and put in the acid solution and rub across the welds and it looks like new when done i hope this has helped.

[toofazt]

passivation is the removal of exogenous iron or iron compounds from the surface of stainless steel by means of a chemical dissolution,most typically by a treatment with an acid solution that will remove the surface contamination but will not affect the stainless steel parts where i work we have a machine that we ground to the welded part then there is a hand held part that you slide a sock type cotton over and put in the acid solution and rub across the welds and it looks like new when done i hope this has helped.

Any specific brand names or machine names I can look up? I've heard you can weld the part in a fully saturated container of Argon, but that's not practical for my needs. I'm really looking for something like you explained...

[Samurai Dave]

Try Surfox

Any specific brand names or machine names I can look up? I've heard you can weld the part in a fully saturated container of Argon, but that's not practical for my needs. I'm really looking for something like you explained...

Walter makes a line of equipment called Surfox. They aren't cheap (expect to be set back about $1500 ), but they do work well.

http://www.industrialtool.com/proddetail.asp?prod=Surfox

[toofazt]

Thanks for the link Dave.

Some interesting info on the topic can also be found here:

http://www.azom.com/details.asp?ArticleID=1142

http://www.avestafinishing.com/pages/Page____517.aspx

[phaxtris]

go to your local welding shop or gas supplier and ask for pickling paste, directions are on the side of the container

[fun4now]

i don't think welding it in a argon chamber will keep it from discoloring.
as for getting rid of it, stop in at your local welding shop and ask them who dose demo's in the area for them. almost every open house at my welding shop has had a guy there to show off the lil cleaner's. they work great but as Samurai Dave said they are expensive. get some out to do a demo for ya.

do you do the polishing or get it like that ? have you tried a polishing compound and a budding wheel ?? i don't know if it will work but i would give it a try with a good cleaning compound then a polishing one. its a much smaller investment than the power cleaner.

best of luck
let us know who it comes out.

[Anti-GMAW]

i don't think welding it in a argon chamber will keep it from discoloring.

Yes it will. It's the atmosphere coming in contact with the stainless after the post flow stops while the peice is still hot that causes it to oxidize.

[welding101]

argon chamber

i would say welding in a argon chamber would be a pain in the a$$. passivate is the way to go .i will get you a name of a passivation machine soon .

[UFO8MyCow]

Try "blue away" you should be able to get it from any Hardly dealer. It is used to get rid of the discoloration on motorcycle exhaust.

http://denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=Main&catId=222&productId=p3182&leafCatId=22204&mmyId=

[journeyman]

I use a pickling paste. it washes off with water. occasionally I'll buff it afterwards. gas coverage is another big one. you may benefit from the use of a gas lense as well. this produces better, less turbulant gas flow, which will reduce heat traces. tighter your arc, the less the heat input will be.

[fun4now]

Anti-GMAW Quote:
Originally Posted by fun4now
i don't think welding it in a argon chamber will keep it from discoloring.

Yes it will. It's the atmosphere coming in contact with the stainless after the post flow stops while the peice is still hot that causes it to oxidize

cool, i knew it was a good idea to increase the post flow time. didn't know a chamber would take the coloration out. learn some thing new every day.