Precleaning Aluminum

[diamondback]

If you fined that your sanding disks are getting clogged then try using WD-40 this stuff works very well.the same goes for carbide die grinder bits.Never use a wire wheel on a grinder.

To help with unloading the aluminum from your grinder, wheel or whatever WD 40 has the possibility to make you sick when you weld back over where you cross contaminated it. Please be careful and check the MSDS. Instead try some anti spatter spray it works great and is intended to get hot.

[fun4now]

a little wax goes a long way tword keeping the grinding disks from loading up, as well as the cutting tools. bee's wax is recomended ( bees wax dose seem to work better) but any old clear/white candle will get the job done.

[ALCOA035]

Oh, the humanity........

I've been welding aluminum sheet, plate, ingots and conduit for over 28 years.
Cleaning whether it be sheet or plate is done via a dipping process. 1) Caustic for any where from 30 sec to 4 mins. 2) COLD water rinse. 3) NITRIC dip for 30 sec to 4 min to neutrilize the CAUSTIC. 4) Cold water rinse. 4)150 deg HOT water dip for 30 sec to 4 min. Then blow dry with compressed air. The 30 secs to 4 min time is dependant on the thickness of the piece. For smaller items, cleaning the area to be welded can be done with an alcohol based cleaner after using Scotch-brite pads, re-inforced flappers and discs without any residual affects.

[jcoldon]

tig alum anodized

Welding anodized aluminum
I have welded alum anodized and never cleaned
the process is simply a button on my tig torch
Full amps a puddle rod stop then next puddle rod and so on
This is the pipe welding process for anodized pipe

I use a sink wave 250 ac
All boat tops and towers are anodized either black silver or gold

The process works on all aluminum you will have to clean dirt and grease
Hope this helps

[DrDave]

Cleaning Aluminum

For uncorroded and un-anodized Al, I find a good mechanical cleaning with a SS brush, hand or power after de-greasing is usually good enough for thicker stock ( over 0.125 or so) because enough heat is generated to burn most anything else off. I avoid emery or grinding disks-they put more crap on than they take off.

For light mat'l, corroded or anodized, I follow this up with soaking or brushing a solution of lye and water on the weld area followed by a good water rinse. I use about 2 tablespoons of lye per quart of water. ( yes, the drain cleaner)The lye actively removes the Al oxide layer (weather natural or from anodizing) and just about anything else! Some alloys will 'smut' - a black film deposit on the surface after being in the lye for a while that is easily removed with a brush and water, or a quick dunk in Alumiprep ( mild phosphoric acid) This grey or black film is the Al oxide, which is what you're trying to get off.

It may seem like a lot of work, getting the hose out, the gloves on etc.. but when it comes to welding 0.020 or .032 sheet your bead won't stop flowing when those chunks of crap appear in your puddle.