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TIG Aluminum prep.

Posted: Wed Feb 05, 2014 10:28 am
by Wen
I've watched all of Jody's videos, and while I'm getting better at TIGing aluminum, I still have a long way to go. I've noticed in Jody's videos that I don't see signs of brushing the aluminum prior to TIGing. Some folks say to use a clean stainless steel brush before wiping down with acetone. Is this the best practice? Some suggest that you don't need to brush if the aluminum is "clean". So what does "clean" mean? Like fresh? Brushing messes up the finish so sometimes I would like to not have to brush it first IF it's not always required.

Do you "always" wipe down before TIGing? Is acetone the best? Can you use isopropal alcohol? Can you wipe down the entire project, or should the wipe down be done to each joint just before a joint is welded?

Proper aluminum preparation would make a good video, maybe it's already been done and I just missed the show. Thanks in advance.

Re: TIG Aluminum prep.

Posted: Wed Feb 05, 2014 2:36 pm
by noddybrian
From my limited Tig aluminum experience I'd say if you have good condition new material try just degreasing first & do a test weld- maybe on an off-cut & play with your balance setting - as long as you can get a clean shiny puddle established leave it at that - as you say wire brushing leaves undesirable marks - if the material is old / well oxidized or heavily contaminated then brush it - but degrease it first as you can easily make matters worse & give a final solvent wipe afterwards - nearly any solvent seems to work - acetone seems to be the favorite in the USA - but it's cheaper over there - if you have trouble sourcing it or the cost is high just use what you have - IPA is fine - I use it most of the time - I only wipe down the immediate area plus a small allowance around it - no need usually to do all of it - but remember just handling the part can transfer enough contaminant sometimes to make a difference - so if the parts are small it maybe worth doing the whole thing - have plenty of clean cloth / tissue & change regularly.

This is from an untrained guy doing non coded / critical bits like aluminum casting repairs / radiators etc - so others may hate on me for my reply - depends a bit on how critical the welds are.

Re: TIG Aluminum prep.

Posted: Wed Feb 05, 2014 5:22 pm
by Wen
Thanks Noddy, I'm looking forward to some more opinion.

Re: TIG Aluminum prep.

Posted: Wed Feb 05, 2014 7:47 pm
by Superiorwelding
Wen,
I never use acetone just because I don't like the smell of it or it burning. A lot of people use it before welding Alum. Our main reason for not using it is safety in the shop, we don't want a fire by accident. As far as wire brushing I use a SS brush on some parts and others we just put together and weld. Not everyone will do this but for their particular application it is no big deal. One suggestion if you didn't want to use acetone is to turn your as balance down for more cleaning action. I am not sure what my Diversions factory settings are but it seems to do pretty well with no wire brushing in most cases. One example I can give of not using a wire brush is I received a Alum job that was a proof of concept. I was required to lay down the best beads I could with absolutely no wire brushing or cleaning. Customer is always right. I actually used the Diversion and it came out beautiful. Just some thoughts.

Re: TIG Aluminum prep.

Posted: Wed Feb 05, 2014 7:56 pm
by Otto Nobedder
I'm of the opinion that aluminum cleaning is seriously overdone, and somewhat overrated. I've done code welds with x-ray, and did less cleaning than I see promoted on sites about aluminum welding.

I will wire-wheel or wire-brush when appearance is not an issue. Where it is an issue, I'll lightly dress the bevels only (sometimes by hand) to expose fresh metal, and I don't usually use a solvent wipe. I will wipe the filler rod with fine emory followed by a dry clean rag for x-ray. I will de-grease/oil when needed. I'll spray with (NON-CHLORINATED!!!) brake cleaner, wipe, rinse with brake cleaner, and blow dry.

On the whole, clean, fresh, dry aluminum requires a minimum of prep.

Steve S