Chemical Cleaning Stainless Welds

[Aeroweld]

Anyone have any experience using chemicals for brightening stainless welds? What products/brand names have you used? Will it also brighten the "sugar" on the backside of the weld?

I'm doing some warrenty and retro fit work on some refridgeration compressors in a new meat packing plant. My portion is aluminum TIG. The plant owner is not happy with the factory SS welds (Mexico) on the drip pans and wants them cleaned up. The contractor I am working for asked me if I knew anything about chemical cleaning SS welds. There is another contractor installing commercial meat smokers in the plant. They have cleaned a number of their welds with a gel like substance. Here lies a dilema. The smokers came from Germany. The cleaner came from Germany. The bottle label is in German. No one on the job can read German. :D
Any help out there?

[bluefish]

go to lincolnelectric.com & go to ask the experts , they will reply within 2 days, i use them for every question i have & they also give me a prompt reply. :D

[usmcpop]

Sounds like that stuff was a passivating "pickling gel", perhaps something like the pickling paste and gels sold by these folks:

http://www.avestafinishing.com/default____491.aspx

Do be sure to check the MSDS sheets before using any particular product. The pickling stuff probably contains both Nitric Acid and, worse, Hydrofluoric acid.

I have heard of someone using Phosphoric acid and an electrolytic pad to remove weld coloring.

[ptsideshow]

Here are some things that might be of use:
http://www.everbrite.net/index.html

http://www.picklex.com/

http://www.derustit.com/

http://www.stellarsolutions.net/

http://www.finishing.com/Letters/index.html
And here is the world's largest collection of information on metal finishing.
:D

[Scott V]

http://www.avestafinishing.com/pages/Page____3296.aspx

I second the Avesta. They make Great SS wire too.:cool:

[B_C]

Unless the back side of a thin stainless sheetmetal job is purged it will SUGAR and as far as a customer is concerned it's junk

[Roger]

Some stainless steel pickling solutions contain Hydrofluoric acid which should be avoided because of toxicity.

http://en.wikipedia.org/wiki/Hydrofluoric_acid
http://www.fap.pdx.edu/safety/hydrofluoric_acid/

[Jerry]

If back side of weld is a concern? Then you should make fixture for purging it. As far as cleaning a weld, I have a HTR heat tint remover which works great for cleaning welds up and yes it will also clean back side but only so good.

[Aeroweld]

Hi Guys,
Sorry for dropping the thread. Didn't realize there were so many replies. Don't know why I wasn't notified.
In any case I ended up using the same product Jerry Streets suggested, the HTR Heat Tint Remover. Pretty much followed what ever the directions said. IIRC, a couple stubborn spots required a little scrubbing with a wire brush but other that that is was apply, let soak, rinse.
I did try a little of the product on the inside of the weld where it had sugared but it still didn't cut the oxide; I didn't think it would. However the customer wasn't concerned about that so neither was I.

Thanks for the suggestions guys.