im bored with nothing to do.....and i need to make myself some intercooler piping. ive made tons of mild steel piping kits for other people.....but i want mine done in aluminum. any tips or pointers on aluminum? im sure prep is way more important....zero gaps...super clean....as far as technique....anybody body got any words of wisdom?? thanks!!

 

btw i have a ton of scraps

 

If you plan to leave the welds on, don't worry about making penetration, just get a nice weld on the outside. Sometimes, you may find it easiest to just fuse (no filler) lightly, the first pass, just to close up the gap...then go back and weld it up. This sometimes will help to make a cleaner weld, since the gap won't let any oxygen up into the weld when you're putting your final pass on.

You're right about gaps though...file them if you have to, to make sure there's no gaps. I try to make them such that I can't see through them, but you don't want as much as 1/16" gap in them at any point or you could burn through and leave a knot on the inside (depending on the thickness of pipe).

Something else to be careful for....brushing too much can actually embed small particles of the brush in the base material. I don't use any sort of power operated brushes like what you'd put on a drill or grinder, for this reason. Small bits of carbon or stainless in the aluminum will make it weld much worse than if it was just a little dirty. If you want it that clean, use emory (sp) cloth, scotchbrite, or even a file on it.

 

Hey Tubo
Cleaning the oxidation from the joint both sides and edge if posible is #1 by sanding with whatever method you have,then wipe down. If you were to tack up a
part and then come back the next day to weld it the oxidation has allready started to reform.
The biggest differents between steels and al is al is a much better conductor of heat which means the heat runs away from the joint so most people try to rush it and get the weld started quick and thats where all the trouble starts. So wait at the start of your joint untill a nice puddle appears, depending on your metal size
and mass you may be there for a while.
If I know what size al you were welding I could help with your setup.
You said you have lots of scrap, try so pratice welds

 

A few tricks on actually welding the material is, AL likes heat. Its not like SS which makes the weld ugly or doesnt penetrate correctly, AL likes a bit of heat. With 1/8" on butt style welds i normally use max of a 125 amps and find myself sitting about 3/4 the way down on the peddle. Getting the puddle started is the whole trick to AL, once you get a solid puddle, its just really dabbing the filler rod in at the correct rate. Get the weld so it looks a little wet, then dab just a little filler in(it may blob just a bit) then give a bit more heat and even that blob out and get the weld so it looks really wet, then go to town. Personally i like using 4043 3/32" filler on all my 1/8" AL welding because i find 1/16" to be too much of a pain in the *** because its too flimpsy and you need to hold it closer to the end, and then you need to keep turning off, but in some cases like pipe, 1/16" works best for me. try both.

 

if you want my suggestion on welding AL, step back and punt.

 

???

 

so i messed around with it for about an hour and a half tonight....after about an hour i got it down pretty good i think.....im really really surprized. i was practicing welding 2 peices of 2.5 inch 16 gauge together. at first it was a nightmare...all i'd do is make huge holes in everything. eventually got it to where once i got the bead STARTED...i could run the rest of the bead just fine. towards the end i was a little bit better at starting but still struggling. anybody have any sugestions of getting that first puddle started?

 

That's the exact problem I have. Once I have the bead started I'm fine, but getting the initial puddle formed, bridging both pieces, causes me all sorts of grief. The problem is always the initial addition of rod to the puddle, it burns back, yet once the bead is "under way", it's not a problem. For that reason I always start welding aluminum somewhere it won't show, because for sure, that initial 1/4" of bead will look like sh*t.

 

yup i feel ya on that one! let me know if you figure out the magical solution!

 

I find using some special chemical cleaners do wonders for aluminum welding also. Maybe some of you guys can post up pics of your aluminum welds. This is my most recient practice on some scrap angles, welded them together to form a box channel.