Aluminum wheel crack repair

[jakeru]

I welded some cracked aluminum automotive wheels for a local wheel restoration company. Here is one that was cracked all the way through.

This wheel was off a BMW "M". On this wheel it cracked when they were doing some straightening.


After some surface prep to remove the paint, I veed out the bulk of the crack on both sides with a carbide burr. This wheel was probably about 5/16"-3/8" thick on this lip.


I then attacked it with my TIG welder on the first side (front and back views)


...And then fully penetrated through on the second side.


I love how once you fully penetrate into the bottom of an aluminum "crack valley", the crap stuck inside the crack floats up out of the crack and up to the surface, as the material flows together as the surface changes to a flat surface.

From here the wheel restoration company is going to grind the weld down, probably check and perform any final straightening as needed, and apply a finish.

I used... max (200 amps) current w/ footpedal, "min cleaning" A/C balance (20% DCEP / Cleaning setting), no pulse, 3/32" tungsten, and I was surprised I managed to get away with 1/16" 5356 filler rod without the tip of the filler melting too often. (I selected that size filler because I had some small "divot" touch up welds to do on another wheel.)

It is "thick aluminum" jobs like these where I appreciate my high duty cycle inverter machine and CK "Trimline" aircooled torch.

[Oxide00]

That's pretty cool. I wish my school taught aluminum welding (well they did but the AC welder broke). Awesome Job!

[Nikola Tesla]

That is awsome. I cant wait to start tinkering around with aluminum on my 250. Ive been doing some homework on it. So far the only thing Ive tinkered with is stainless and various steel grades. Ive actually heard aluminum is the way to go as its a good way to learn how to control heat. One thing at a time. I preffer to master my baby steps before I move onto moonwalking.

[presure2]

hehe...i got a buddy selling a nice set of wheels super cheap cause one of them has a crack very similar to the one in your first pic..just not as long..

[DaveO]

Good on ya! That sounds like a sideline business, or a money-making hobby waiting to happen. What does a new wheel cost, and how much money did you save somebody?

[jakeru]

Thanks for the kind words, guys.

I welded another cracked wheel today for the wheel repair company. This wheel was an aftermarket three-piece wheel that came off a Porsche. Quite light weight for its size, looked like it had spun-formed wheel shells and a nice forged "BBS style" center. Apparently the customer discovered this crack when he was having his tires changed. I would guesstimate a wheel like this would run in the several hundred dollars per wheel range (each) to buy new.

Anyhow I did pretty much the same technique as on previous wheels - cleaned it, veed out the crack, welded it up. Since it was thinner (lightweight, spun formed) it didn't take as many welding amps as the previous thicker wheels I worked on. I took my time and let the cleaning action of the torch do its job, and kept going until the middle of the crack flowed out nicely and was totally continuous, solid metal.

The wheel repair company should be able to take it from here, straighten it, grind the uneven weld bead down flat, and make it look like new. I like working on wheels that have a bare metal finish like this one the best, instead of ones that are painted. On this kind of wheel, you can't just trowel some bondo over the blemishes and cover it up with paint.

Pics - Before:
Attachment 1243




Prepped for welding:


After welding:

Attachment 1242

[presure2]

Nice work as usual, Jake.

[jakeru]

I've done a few more crack & divot weld repairs for the aluminum wheel repair outfit.

Here is my latest I just welded today. This AMG (mercedes) wheel measured a little over .40" thick.
Attachment 1643Attachment 1649

Before repair:
Attachment 1642Attachment 1641

I veed the crack like I usually do and also used an aluminum oxide impregnated plastic bristle cup brush to remove the paint down to bare aluminum in the area around the weld. It took a little time to work, but worked well. The bristles get into and clean irregular surfaces really well. Followed by a solvent clean.
Attachment 1644Attachment 1645

The key to penetrating all the way through on thick material like this is to bevel the joint. I like to go over the joint with my TIG torch at a low power level first, using the AC cleaning action to blast away any remaining contaminants and burn/evaporate any remaining oils/solvents that may be stuck in the crack or in the pores of the metal. Then when it is all looking good, I hit it with the real metal melting power.
You know what, I didn't feel like I needed any more power than the 200 amps my machine can muster. I had it set at about 25% cleaning (EP%), no pulse, and the machine has a fixed 60 Hz AC frequency.
Attachment 1646Attachment 1647

3/32" tapered & blunted lanthanated electrode worked well; I didn't need to step up to 1/8". I did prepare the blunted tip with a smooth shaped dome tip, with no sharp edges. I did dip it once near the end, which is not extremely uncommon and usually calls for changing the tungsten on an aesthetic weld. Since this weld will just get ground down, I just rolled with it. Here is what it looked like afterwards, starting to get a little bad but it was still making a fairly decent arc shape even like this:
Attachment 1648

Do you guys want to hear something funny? The aluminum wheel repair outfit that keeps sending me these wheel weld jobs has a top-of-the-line, Dynasty 350 TIG welding outfit in their shop, dripping with the most expensive accessories: matching Miller watercooler, top of the line weldcraft "crafter series" watercooled torch, etc. They said they spent $8k on it, but apparently no one there knows how to use it! Unless you count customers seeing it and being impressed with the "name" and how much it cost.

They seem to like having me do all their welding work. They told me the previous welder who did their aluminum wheel TIG welding, often would have to re-weld it, as many as four times on one wheel, because his welds would often crack during wheel straightening. They said the ones I welded have yet to crack once during straightening. That was pretty nice to hear!

[watercooler]

His welds crack because he might not have gotten enough penetration down to the root of the crack and only did a cover up so the crack was still present underneath.Your way is pretty good seeing that you went deep down and build your way up.What I also notice on my own is that pulsing helps blending the aluminum together and sucking out the air particles out of the welds which will leave you with sold aluminum under every pass you do.Try it on some scrap aluminum next time and see for yourself.That's a great job on the side to have which only takes skill and a tig welder and in return you get paid for something you love doing.