Cracked Volvo and Axxis aftermarket wheel TIG welding repairs (jakeru's #5)

I welded a batch of two cracked cast aluminum wheels. The first one was a Volvo OEM wheel. I was actually quite impressed by its light weight!
Attachment 2478

The second one was an Axxis aftermarket wheel.
Attachment 2477
The volvo wheel had a "y shaped" crack.
Attachment 2479

The Axxis had a straight crack.
Attachment 2476

The process for preparation is the same... remove all paint from the surface around the crack, and vee out the crack with a carbide burr.
Attachment 2472

I used a dental scaler to scrape a bunch of crap out of a crack that relatively wide:
Attachment 2473

Before I weld them, I like to do some more cleaning (or rather to "test the cleaning") by running a low-amp arc over the area to be welded until the area is completely etched and is arcing without producing lots of smut (black or other colored, soot like powder) where the metal needs to flow. This is actually one of the more dirty wheels, but this shows how it looked before I began to final, high-power welding.
Attachment 2471

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Then I weld them from both sides.
Volvo:
Attachment 2480 Attachment 2481

Axxis:
Attachment 2482 Attachment 2483

The local wheel repair company (my customer) take the welded wheels from here, mounts them in their runout-measuring jig and straightens as needed by hand, grinds the welds down smooth, and refinishes the wheels.

I much prefer working on painted wheels like these than I do on chrome plated ones. My favorite wheels to work on however are the ones that are bare aluminum. Those are usually forged / spun-formed. Both of the wheels pictured here are cast.

I usually go for about 45 minutes a piece per wheel, with about 1/2 of that time being in preparation, and the other 1/2 time being in welding. In this case I think I was a little faster.

I do wish I veed out the dirty crack (rather than dental scraped) because there was still a lot of junk in there when I started welding.

I used 3/32" 5356 filler, (as well as perhaps a smattering of 1/16" 5356). The 5356 seems to leave a strong, ductile deposit on wheels.

After using a couple of very high amp welding machines last week (350 amp+) my 200 amp was feeling a little "limited", for the first time that I have ever noticed. Even with full amps and min AC balance cleaning setting. I wonder if the feeling will go away as I get used to it again. Oh well, I do still really like my machine. :) Nothing else like it I can throw in the back seat of my car, and take to whatever shop is needed on moment's notice.

My objectives for the most successful wheel weld are:
1. Fully penetrate, for strength
2. Put down a solid deposit with no (or minimum possible) porosity, for strength
3. Make the weld bead as narrow as possible (to ease the straightening and finishing process)
4. Leave no (or only very slight if any) undercut at edges of the weld bead, for strength and lack of a stress riser

That's some nice work. It looks like you have gotten your monies worth out that 07 Super 200P.

Are there certain wheels that you have to pre-heat?

I don't need to pre-heat to weld reasonable thin aluminum (up to about 3/8" or so thickness), ever since upgrading my torch from a WP17 to a CK trimline 210 (200 amp @ 100% duty cycle).

The new torch is really sweet, and the Super200P has some really impressive duty cycle @ 200 amp output to go with it, so they make a pretty potent combination for a wide variety of jobs. Back when I only had the original WP17 torch, if I tried welding very thick aluminum (like cast aluminum intake manifold, for example) I would melt down the torch cable and blow contamination out of the shielding gas - don't get good results what that happens. (And I detailed that in my "overheating torch" thread.)

On something like an aluminum wheel that is likely to be heat treated, I prefer to give minimal heat input to the part, to reduce the portion of the wheel that becomes annealed (losing strength of heat treating.) That means using the intense, concentrated TIG torch to apply all the heat necessary for welding, rather than a broad heat input such as by an oven, or by a diffused heat combustible-gas torch flame.