TIG Welding Aluminum Doubler Repair

Two very common tig welding repairs are:

  1. Filling an aluminum hole
  2. Welding an aluminum doubler also known as a Scab Patch

In this video, we are doing both.

Its common to need to weld a mis drilled hole, a worn rivet hole, or a hole with damaged threads.

For welding a hole in aluminum sheet metal, it helps to clean the hole first.  A slightly larger drill bit in a cordless drill is one easy quick way.

For filling holes in aluminum I usually let the cleaning action of the AC arc clean the area before I actually melt the aluminum.

Then, I gradually add filler metal using just enough amperage to move the puddle along.
After I make it around once, I add a little amperage and keep going in circles until the hole is completely filled.

To avoid a crater crack, I slowly taper off amperage while I keep the arc moving around.

Welding an Aluminum Doubler patch

tig welding aluminum doubler patch


Whether its a tank, a pontoon, or a media blast cabinet, a doubler patch is a common repair.

Some industries like general aviation have standard practices or codes that specify doubler thickness, dimensions, radius, and procedure.

Its never a bad idea to radius the corners on an aluminum doubler patch because sharp corners can be a stress riser where cracks might form in service.

I cut the patch out of a piece of scrap tubing the same exact diameter and thickness as the piece I was patching.

I used some Stronghand Tools long locking c clamps to hold the doubler while I put 4 tack welds on it.

Since the doubler was .070” (1.7mm) thick I only needed 4 tacks but if I was welding on thinner aluminum, I might have tack welded every inch or so.

I was using a CK worldwide mt200 ac dc  machine and this machine has all the sweet spot settings highlighted in blue on the knobs and that is exactly how I set the machine.


Best tig cup for tig welding aluminum


There is a whole lot of discussion on what is the best tig cup for aluminum.

I used a #8 furick pro clear cup for this video but mainly because it helps everyone see the puddle better.
Its a great cup for aluminum but some people prefer using a standard #5 cup with standard collet body.

The video below shows tig welding aluminum with a standard #5 cup.

Both gas lens cups and standard cups have their place for tig welding aluminum...

it mostly just depends on the application or personal preference.