random welding question....

can you weld steel to aluminum? i was going to ask a friend to weld on a aluminum cap onto a steel pipe. is this a bad idea? is it a bad thing to weld different types of metal?

 

nope

 

weld will never hold even if u try it

 

what about bolting the cap to the steel?

 

what do you mean?

i understand not to do it, but does anyone know why this is so? why it wont hold?

 

i believe it is because both steel and aluminum need two completely different temperatures to bond (aluminum is much lower than steel). don't quote me on it tho...but i'm almost certain it has something to do with their heating properties.

 

also i think aluminum uses a different gas to bond it.. don't quote me on that.. and what are u trying to mount? got pics?

 

Actually, my shop teacher from HS told me about this factory tour he went on tand they welded an AL to steel. It was a gnarly pulsed TIG-machine, but of course the weld is only as strong as teh AL.

But i don't htink you'll have the machine, so don't even thing about it. But why an AL cap??

 

im sorry, but at the moment i do not have any pictures.
although, i should soon... as in maybe tomorrow, or in a few days, to a week.

what my plan was, is make a steel tube bumper, for the rear, and i wanted to cap off the sides. i do not have any steel sheet metal, but i have some stolen street sines that i could use to cap it off. it really would not need to be on there to hold up anything with weight, just has to be strong enough to hold on its self on... a 4 inch round peace of AU.

 

a 4 inch round piece of Gold?? What?

Go to the scrap yard, or to Home Depot. They have got sheet metal, 18gage usually (~.050inch thick).

 

oh my bad. have not been paying attention in chem... as of course you know, aluminum... so it wont hold at all? trying to do as less work as i can....

darn.

 

Yeah, i was just messing with you.

No, don't even attempt it. You *might* get it to stick with TIG, but it wouldn't even hold much i am sure. Al melts so low compared to steel, it wouldn't hold. It'd be like a sticky booger on a table.

 

You know, i guess you could always epoxy it on.That way it holds, and you can get a smooth edge. There are some good metal epoxies out there.

 

monkeysteeler12 save yourself the headake and go buy a small sheet of light gauge steel. and screw the street signs on the wall in your garage or room or where ever your man cave is.

 

Yes you can bond the 2 pieces together, its just not a weld. Its called brazing and Im pretty sure you can do it with a map gas torch. I have done it with an oxy-acetelyn set up. Take a look at Home Depot and see if you cant find yourself a brazing kit.

 

alright, thanks a lot guys!

 

sheet steel is dirt cheap, go buy some and use it.

 

True story. Shouldn't cost more than a few bucks. You'll spend 5 dollars to save a million dollars in hassle and sanity.

Brazing is tough to do! And I'm pretty sure brazing is for using brass, not aluminum anyways.

 

When Ive done brazing it was with 2 pieces of steel. You can bond any metals with brazing. So yes you can braze brass too.

 

Ok the only brazing I have done was brass onto steep for a lamp that I was making. It's tricky stuff!