[genarr3]

I’m having a devil of a time trying to TIG weld some cast aluminum. I’m a hobby welder, by no means a pro. Specifically what I’m trying to weld is a motorcycle swingarm. I bought a junk one so I could practice before I tried anything that counts.
Exactly what is happening is the welds are very porous. When I make a puddle I can see crud in the puddle that won’t completely go away. I’ve tried carefully cleaning and it didn’t really help. I’m using 4043 rod but I don’t think rod is the issue because I can see the problem starting even before I add any rod.

As far was the quality of the casting these things can be welded. It’s pretty regularly done, and with nice looking welds - just not by me.

For the life of me I can’t figure out what I’m doing wrong.

[pro mod steve]

CLEAN CLEAN CLEAN. What I had to do was wire brush make a cleaning pass with torch no filler to boil up crap and clean again. Finally added filler and ground the bead down and repeat till I get a clean base its a pain sometimes but it can be done.

[pro mod steve]

That is the brief of it but I am sure there are some way more experienced welders than me that will chime in.

[genarr3]

CLEAN CLEAN CLEAN. What I had to do was wire brush make a cleaning pass with torch no filler to boil up crap and clean again. Finally added filler and ground the bead down and repeat till I get a clean base its a pain sometimes but it can be done.

Yeah, it's bugging the hell out of me because I've seen plenty of extended swingarms with beautiful looking welds. So I know it can be done.
I'm going to try that, thanks.

[ogorir]

a few tips for cleaning: get an aluminum-specific carbide burr. they have less flutes so you don't need to lube them to keep them from loading. also, get a new stainless wire brush, use it often. don't use any abrasive cutting/grinding wheels/discs unless you really, really have to and always file any edges you do use abrasives on with a clean file. use acetone (I use lacquer thinner which is mainly acetone,xylene, and toluene) and your wire brush to clean your weld area just before welding. if you're worried about soot, get a plumbers air-propane torch w/ the built in igniter and dance it over the area after you've cleaned w/ solvent to evaporate it out of any pits.

also, a dental pick works well for picking crap out of little pits. also, a really sharp small drill bit works, too. make sure it's new or really clean, though, because the drill can smear a layer of aluminum and the crud you're trying to drill out around the inside of the hole like a bearing sleeve.

you might also try preheating using the propane torch or an old barbeque grill. don't overdo it, 212f (boiling water) usually makes enough of a difference. you can also run the torch over the area you're going to weld w/ just enough amperage to get it to puddle, then file/drill/burr the crud out and repeat until it's clean. it's just one of those time-consuming things.


ooh, and make damn sure you're gas is good by welding something similar that you know is clean! no sense in wasting an entire day because of a cruddy bottle of gas! same goes for tungstens. if this is critical, buy a box of brand name thoriated or lanthanated (sylvania, weldcraft, ect. not radnor or some knock-off). and run a scotch brite down your filler rod. you don't want to introduce anything after you get your puddle clean.

[genarr3]

a few tips for cleaning: get an aluminum-specific carbide burr. they have less flutes so you don't need to lube them to keep them from loading. also, get a new stainless wire brush, use it often. don't use any abrasive cutting/grinding wheels/discs unless you really, really have to and always file any edges you do use abrasives on with a clean file. use acetone (I use lacquer thinner which is mainly acetone,xylene, and toluene) and your wire brush to clean your weld area just before welding. if you're worried about soot, get a plumbers air-propane torch w/ the built in igniter and dance it over the area after you've cleaned w/ solvent to evaporate it out of any pits.

also, a dental pick works well for picking crap out of little pits. also, a really sharp small drill bit works, too. make sure it's new or really clean, though, because the drill can smear a layer of aluminum and the crud you're trying to drill out around the inside of the hole like a bearing sleeve.

you might also try preheating using the propane torch or an old barbeque grill. don't overdo it, 212f (boiling water) usually makes enough of a difference. you can also run the torch over the area you're going to weld w/ just enough amperage to get it to puddle, then file/drill/burr the crud out and repeat until it's clean. it's just one of those time-consuming things.


ooh, and make damn sure you're gas is good by welding something similar that you know is clean! no sense in wasting an entire day because of a cruddy bottle of gas! same goes for tungstens. if this is critical, buy a box of brand name thoriated or lanthanated (sylvania, weldcraft, ect. not radnor or some knock-off). and run a scotch brite down your filler rod. you don't want to introduce anything after you get your puddle clean.

Funny you mentioned the aluminum specific carbide bit, I just ordered one yesterday. Great tips, thanks.

[mspaul]

Hi,


Thank to share this information with me, Because It show the information regarding TIG cast Aluminum,This is important for all business man,
But I have read another site, they also provide good information for the TIG cast Aluminum,


Please check through signature,

Welder

[genarr3]

I tried out my new aluminum carbide bit. Huge difference, just a light grinding of the top surface exposing fresh material. Much less crap in the puddle, still not perfect, but way way better.

[jakeru]

They work great. Just be careful about using them, if you find it is "jumping around". The aluminum cut teeth seem to be more fragile. Any breakage I got on a carbide burr has been when it was chattering, or vibrating excessively.