Ask your WELDING questions here.

Those aluminum welds are looking better. Usually its not a little cupon you are welding so the heat does not hang around the same.

When aluminum is right, its Dip, dip, dip...... at a pretty good clip. always back off the heat near the end of the weld. Back off twice as much if the end is at an edge. I start at the edge if I can that way its easier and will look better.

With aluminum travel speed and heat work with each other. Keep running beads and you will see.

Well I posted months ago looking for tips as I was tackling building my own exhaust. I finally finished so I figured I'd post back some photos. I got some good advice here and elsewhere and certainly learned a lot in the process of making it. I feel very comfortable with stainless now. Anyway, here's a couple of shots of the final product.







I like that last one as it shows the first header flange I cooked which prompted me to go on a mission to learn how to weld stainless better and then on the right is the last header flange I made which I think sums up my learning curve.





There's more photos in my build thread but I feel like the bike is "finished" for the moment. My fancy pants X pipe didn't work as well as my H pipe (H = 1hp gain) so I'll have to remake that as the H was only done as a test. Still, I learned a lot in making the whole thing and the bike runs great making some kick ass torque. Quite happy.

Gregor

<img src="https://gregorhalendaphotography.smugmug.com/Motorcycles/KTM-950-to-990-conversion-with/i-Fk9ScBF/0/L/DSCF0321-L.jpg">

That is some right pretty welding, right there.

Very first weld ever yesterday - flux core 1/8" butt joint. Gotta start somewhere!

Some advice on how to change this rack on the back of my subframe. I need that upturned bit made flat. Can I just cut it off, then bend a new piece and butt-weld it on? My woodworking background says, no way, butt joints are bad. But will it work with welding? Or should I use an insert to strengthen it...? Advise me!

Take rack off, heat the bend red hot, and straighten it out.

I don't own the proper torch -- I think. What is the proper torch? I do own a MIG welder...

Do you have a weed burner and a propane tank?

Dry grass hillsides in all directions. Nobody has that gear around here.

Not to be too cheap...but what's the cheapest rig to get that piece hot enough to bend without folding?

Sutherngintelmen, looks way too cold to me, increase the wirefeed/amperage.
if you're using a little 110/220v chinese box you'll never get it hot enough to do any quality welding with it. (flux core REQUIRES spray transfer. that over 180amps on 0.035 wire. otherwise its short circuit and the flux gets burried in the weld causing inclusions. eventually leading to cracking)

DiabloADV when you weld metal, the weld is stronger than the base metal. yes, you can cut it off and weld it back. support & tack it well like you want it & then get at it. its a small part so you can easily turn it around to keep the welds flat & easy.

If I were to heat it and bend it, it would wrinkle almost for sure. I would cut the bend out, find rod, tube or pipe to slip inside of it and weld. I would NOT do it on the bike.

Nice thing about metal. If you take too much off, I can put it back on.

I suck with wood!

Good luck, show pics when done.

David

Thanks - i'll experiment with faster wire / more amps and see what happens. Didnt make the very logical connection between speed and heat. The wire was 0.030 with feed on 40 and amps at 3 of 4.

Using a Hobart 140 which has an OH sticker on it but may just be c-suite and marketing

A rose bud (oxy-acct) has a lot of BTUs but it is concentrated in a small area. Not practicle for heating two different areas that far apart in order to sraighten the rack. The bent tubing will need to be cherry red to straighten with out colapsing, Both pieces, With a rose bud one will cool while the other is being heated, a weed burner puts out a lot more BTUs in a larger area and it should be possible to keep one side red hot while heating the other side. Alternate sides during the heatig process and try to keep both sides at about the same temp.

Equipment rental stores in the area should be able to furnish the weed burner.
ps: If you have access to two sets of oxy/acct. tanks and two rose buds that should work but don't try to run two rose buds on one set of tanks and NEVER get into the RED zone on an acct. regulator.

As the rack tubing is likely to be quite thin, you should be able to heat and bend it using a butane or propane blow lamp.

heating and bending it would be tricky since you would need to do both sides at once and need a LOT of heat. Since you have a MIG I'd cut the end off, cut the bend out, then put inserts that fit well in the joints (with a small gap between the pieces) and weld it all back together....if you do it right the joint will be strong and wont look too bad, I shortened a kickstand this way recently and it works fine. There is something similar at http://www.weldingtipsandtricks.com/stainless-steel-tubing-tips.html

That rack would be very easy to bend straight, using a propane torch, and shouldn't take more than about 20 minutes to do. If there are any wrinkles in the bend area (unlikely), then simply MIG weld over them, and linish to a perfect finish.

I'm getting ready to fabricate a winch bumper out of a combination of 6061-T6 and 5052 aluminum plate. 6061 for framing, 5052 for cosmetics.

Would 4043 or 5356 be a better filler rod for this application?

I've read that 4043 is less prone to cold cracking on 6061, but 5356 has better strength and ductility than 4043. It won't be subjected to constant temps above 150F, which is not good for 5356. It also won't be anodized, so color match isn't an issue.

Sounds like either would be fine as the filler is stronger than the HAZ of each joint. Just not sure on what's best for a deer-smashing bumper application. 5356 maybe since shear strength would be the biggest issue?

Thanks in advance.

Nice work!

I don't think it would matter much, The 4043 flows better, so it is what I would use. Joint design and bumper design will have more to do with strength than filler.

David

You can use 4043 filler for most aluminum welding, and it means less chance of weld cracks on some jobs.