×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Cleaning Aluminum

Cleaning Aluminum

Cleaning Aluminum

(OP)
What is the right solvent to use for cleaning Aluminum (6082 T6) before welding? The parts to weld have been machined (turning and milling), using cutting fluids. The material has been recently bought, does it steel need wire brushing, after cleaned with the solvent?

Thanks.

RE: Cleaning Aluminum

I wouldnt wire brush it with steel, that seems like it would be a good way to induce Fe particles into the Al.

RE: Cleaning Aluminum

You should brush the aluminum with a dedicated stainless steel brush (not used on or contamianted by any other material) just before welding.  Aluminum oxides form relatively quickly and have a much higher melting point than aluminum, if left in place, either the aluminum gets overheating by the time the oxides melt or the oxides are entrained in and contaminate the wled.

RE: Cleaning Aluminum

(OP)
Sorry, for my mistake, I wanted to say:"...does it still (not steel) need wire brushing"

I am asking about wire brushing, because the component is to be anodized (after welding) and as I said previously, the material is recently bought meaning it may have a smooth oxide cover, which mean it could be “easily” removed by the arc itself. (???)

What about the solvent? What to use?

Thanks

RE: Cleaning Aluminum

99% Isopropyl alchohol or 99% acetone would be the solvents that most readily come to mind.

RE: Cleaning Aluminum

All sources of contamination must be removed from the joint. It's a good idea to clean back an inch or so, more in cases where the possibility exists for contaminants to melt with the heat of welding and enter the weld area.  The solvents mentioned by rorschach will work or MEK is another option.  The caution is that these are all flammable. Stay away from chlorinated solvents.  As TheBlacksmith notes oxides must be removed by either a chemical compound or by mechanical means ie. wire brushing.  As noted use a clean stainless steel wire brush.  Cleanliness is absolutely mandantory in producing sound welds in aluminum alloys.

RE: Cleaning Aluminum

I weld stuff like this regularly, so here's the trick to good aluminum welds.
1) If your parts are shiny, not dull,they don't need
   brushing because they're not oxidized.
2) Brush marks usually look really bad after anodizing
   because the color makes them stand out.
3) Almost any solvent will remove more than enough oil
   film,but acetone,MEK,naphtha and denatured alcohol
   all do very well.
4) The continuous hi-frequency setting on your welder
   is what actually cleans away most of the oxidation
   anyway.
5) THE ALLOY OF YOUR FILLER WILL AFFECT THE LOOK OF
   THE ANODIZED FINISH MORE THAN ANYTHING ELSE. Check
   with your supplier about color compatibility.

Alan L. Bass, toolmaker

RE: Cleaning Aluminum

Vouager687 makes a very good point concerning the color match with Al welding.  If the required physicals allow it it definitely pays to match the base allow for for bare metal appearance and as posted check with the anodizer for matching after anodizing.  At times this could take 2 different filler metals.  

RE: Cleaning Aluminum

Voyager687 makes some good suggestions, but I'd like to offer a small clarification to item 4.  In GTAW welding the use of Direct Current is not common, rather Alternating Current is the current of choice, that being, because both DC+ and DC- offer certain advantages.  DC+ offers the cleaning action referred to by Voyager687.  The problem encountered in using Alternating Current is the fact that the current drops to zero and reverses direction twice in each cycle making for an unstable arc.  The most common way to get around this problem is to superimpose a high frequency, high voltage current on the regular welding current.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources