I've got an item that is aluminum(I think it is cast... not sure). I need to weld a threaded "bung" to it. Is there any special treatment I need to worry about aside from a rod for use with it?

TIA,
John

Just clean it. I've only TIG welded aluminum...i hate how you can't tell if it is hot or not.

CJ

preheat it good so that the weld penetrates right off the bat so that it seals good. I use my mig welder that is set up for aluminum and it works good but once the work it gets hot it welds much better. Once it is hot you need to be on and off the trigger or foot peddle or the puddle will sag or just drop without much warning because it gets so hot that it puddles up too much and can't support the weight.

If your not used to welding aluminum it might not be a bad idea to call around to some smaller 'job shops' and find someone to do it. If its cast its porus, and if it's had oil or something in it it needs a good cleaning for a good weld. If you drill the hole where you want it and make sure it's a good fit it should'nt be more than a jug of wiskey to get it done.

Many automotive castings are often 4xxx, 5xxx or 6xxx series alloys. Here is a useful chapter on how to weld aluminum:
http://www.adtdl.army.mil/cgi-bin/atdl.dll/tc/9-237/Ch7.htm#s4

Besides the fact that it welding aluminum is very different than steel, it takes about 50% more power to weld aluminum. I can only weld about 3/16 inch aluminum because anything over 200 amps welding current trips the 50 amp 220V breaker in my house and that is the largest breaker I can get in my box. It isn't going to be an easy job with your average home welder, so you may want to consider farming out to your local professional.

<img src="http://members.home.net/cglabe1/photos/welder.jpg">

Thanks for all the good info... looks like I'll take it to a shop for the "6-pack" weld job :p

Wait there a minute!!! You didn't say what kind of machine you have to do it with, and what exactly is the bung going on? I certainly belive tig is obviously the best way , and if you dont have one , and you got someone who does six pack jobs by all means do it. There are other ways though but even the gas or stick electrodes will cost you more than a six.
weldpro

Originally posted by weldpro
Wait there a minute!!! You didn't say what kind of machine you have to do it with, and what exactly is the bung going on? I certainly belive tig is obviously the best way , and if you dont have one , and you got someone who does six pack jobs by all means do it. There are other ways though but even the gas or stick electrodes will cost you more than a six.
weldpro

The bung is going onto an aluminum(cast I believe) transfercase housing(actually a part that bolts onto the tcase).

My choices of "machines" are a porti-mig welder with no gas and an onboard stick welder. Of them, the onboard stick welder would be the "easiest" to get ready for welding aluminum... but I have a feeling it would only burn the aluminum to a cinder:D

For welding aluminum the oxy acetylene method works great, not quite as easy or pretty as Tig but pretty damn good.

They make a special blue tinted glass for your welding helmet that makes seeing the weld puddle on aluminum much easier to see. Most welding shops carry them. TIG is the way to go, but I have MIGed and Gas welded aluminum with good results. Just spend a little time practicing. Converting a MIG machine to aluminum use can be time consuming, you have to change the liner, gas and polarity. A spool gun for your MIG is nice if you have the $$$.

:beer: If you was my neighbor...I'd do it for a 6 poke. TIG, AC with argon purge gas and 4043 alloy filler wire. I weld for a living and using a high frequency machine on AC helps to clean the metal. Take it to your local welding/beer drinking shop, it's hard to beat someone at their own game and the results will show. Remember...if it was easy.....women would do it!!!:smokin:

if you can try to pm metalmender he is the best welder i have seen yet he welds aluminum for airplanes 40 hours a week he will be glad to help

MILLER DYNASTY DX GTAW adjustable hrtz from 50-200
i love that machine , i run it all day everyday:smokin:

Originally posted by toyletrider
if you can try to pm metalmender he is the best welder i have seen yet he welds aluminum for airplanes 40 hours a week he will be glad to help
Hey Toylet
Thanks for the plug ;) but I think Lil'john knows which route to go now.
Hell I would it for a couple :beer:
rich