Best Way to Weld Aluminum

[bdhsfz6]

I know...I know, this subject has been done to death here over the years but searches give me little advice specific to my situation.

I have a Hobart AC/DC stick welder and a Hobart MIG wire welder. The MIG has a gas regulator which I don't use since most of the welding I do is on mild steel. Switching wire types and setting up the gas takes more time than the welding project itself. Keeping a supply of gas is also an issue since I would use so little.

Most of the aluminum I work with is 6061 or 6063 angle & bar stock 1/8 to 1/4 thick. Are there any tricks & tips to welding this material using MIG or stick machines without gas? I've tried using aluminum welding rod in the past but the weld always looks like the dog's breakfast.

I've been considering another welder, perhaps TIG to use exclusively for aluminum but I hate to spend the $$ since I would use it so infrequently. Gas is also an issue since welding supply shops are a great distance away. Are there small disposable gas cylinders available online? The ones I've seen are only available in Europe, likely due to US shipping regs.

Any suggestions?

 

[etpm]

I know...I know, this subject has been done to death here over the years but searches give me little advice specific to my situation.

I have a Hobart AC/DC stick welder and a Hobart MIG wire welder. The MIG has a gas regulator which I don't use since most of the welding I do is on mild steel. Switching wire types and setting up the gas takes more time than the welding project itself. Keeping a supply of gas is also an issue since I would use so little.

Most of the aluminum I work with is 6061 or 6063 angle & bar stock 1/8 to 1/4 thick. Are there any tricks & tips to welding this material using MIG or stick machines without gas? I've tried using aluminum welding rod in the past but the weld always looks like the dog's breakfast.

I've been considering another welder, perhaps TIG to use exclusively for aluminum but I hate to spend the $$ since I would use it so infrequently. Gas is also an issue since welding supply shops are a great distance away. Are there small disposable gas cylinders available online? The ones I've seen are only available in Europe, likely due to US shipping regs.

Any suggestions?

I don't know what size your mig machine is but if it is a 140 Amp machine it is too small fir 1/4 or really even 1/8 unless you pre-heat the work. TIG welding takes practice to get good welds, but the relatively inexpensive and new square wave machines make welding aluminum much easier. TIG machines also have the added versatility of being able to TIG braze using filler metals like aluminum bronze and silicon bronze. Plus you can weld stainless steel. And of course plain old steel. The gas required for all these processes is argon. To do the same with MIG would require a different type of gas or gas mixes. If you can afford a TIG machine and have the time to practice then get a TIG. I have been welding for over 50 years and have TIG machines, MIG machines, stick welders, and oxy-acetylene torches. I use them all but if stuck with only 1 it would be the TIG.
ERIC

 

[JimRB]

Buy a big bottle of argon and it could last years if you really do not weld much. I do not tig much but I think I have swapped out the argon tank once. I have a bottle about 4 foot tall which last a while for as little as I weld. Same size bottle for my tig and mig welders. Swapped out the mig mix also in the past year. Tig welding aluminum is almost fun. I have Everlast machines which have treated me well so far. I had a Hobart Handler 135 mig which worked ok but popped the 20 breaker too much for the thicker welding I was trying to do.

 

[Tinhack]

For Q&D aluminum projects, I use aluminum brazing rods. You can do that with a propane torch. I have the TIG and an aluminum spool gun, but I don't bring that stuff out unless it's big project. I can braze a part for a repair and have it back in service before I get the TIG set up.

Critical for all aluminum work is it needs to be clean and bright right then and there. Don't clean it and let it set over night or even for a few hours.

 

[WinterDeere]

Watching... also have a Hobart Handler 175 MIG, which I use regularly for steel (with C25 gas). Interested in getting gas/wire for aluminum, but looking for feedback on how well it actually works. Stainless would be handy for boat projects, too.

 

[Langanobob]

I use them all but if stuck with only 1 it would be the TIG.
ERIC

ERIC,

What TIG machine do you have now? Is it one of the newer high tech inverter machines with all the many different settings and features? I have an ancient old Miller DialArc 250HF that I use for TIG and I’m wondering if it’s worthwhile to upgrade to a modern machine. Asking here since I think it ties in with and supports the OP’s question.

 

[etpm]

ERIC,

What TIG machine do you have now? Is it one of the newer high tech inverter machines with all the many different settings and features? I have an ancient old Miller DialArc 250HF that I use for TIG and I’m wondering if it’s worthwhile to upgrade to a modern machine. Asking here since I think it ties in with and supports the OP’s question.

I have two TIG machines, a Miller Goldstar and a Lincoln 200. The Goldstar I have is a special machine in that it has 4 ranges instead of three. The 4th range is from 1 to 10 amps. I used this very low range for welding stainless foil. The Goldstar also is just a sine wave machine when using g AC.
The Lincoln is only a 200 Amp machine whereas the old Miller Goldstar is 300 Amp machine. So I am keeping the old machine just in case. Anyway, the Lincoln is indeed an inverter machine. It weighs about 70 pounds. The Miller weighs about 700 pounds yet only has 33 percent more power. The Lincoln is an excellent machine and I was amazed how easy aluminum welding was with the Lincoln compared to the Miller.
You can buy welders that have more options, and are more versatile, than the Lincoln, for less money. But they will be made in China. When I bought my Lincoln I also looked at Chinese machines, and almost bought an Everlast. But the reviews weren't that good for the Chinese machines but the Lincoln had much better reviews and my purchase was for my business and I needed reliability and quick service.
Now I would probably buy the Everlast because they seem to have ironed out the reliability problem and apparently the quick service issue too. Though I have no direct experience.
All the new welders, except maybe some stick welders, are inverters machines. This is actually good for several reasons. The main reason being that inverter technology is mature and well understood. Every computer made since at least 1985, and maybe before, has an inverter power supply. This technology has blossomed and is used almost everywhere voltages need to be transformed to any significant degree.
Inverters are so popular because they are efficient and versatile. The efficiency comes in a large part from lower energy losses by using higher AC frequencies which leads to lower losses in the inductors changing the voltages and because smaller inductors are used. The versatility comes from the fact that DC must be changed to AC for an inverter to work. In fact, that is why they are called inverters. But once DC is chopped into AC at a certain frequency why not change the frequency to whatever you want? And, unless you need a smooth sine wave, why not keep the square wave that inverters naturally produce? Then, because you can switch the AC at whatever frequency you want, it makes sense to switch it at the best frequency for the job. And even the duty cycle of the square wave can be chosen easily. So much time at positive and then so much time at negative.
The description above does not cover all the advantages and versatility and waveforms of modern inverter power supplies, but does give a general outline of why virtually all modern welders are inverter power supply machines.
Finally, do I think it is worthwhile to change to a newer "high tech" inverter machine? If you are welding much aluminum then yes, it is definitely worthwhile.
Eric

 

[sandman2234]

If you can braze with a torch, it is a good step towards being able to TIG weld. They are similar in the movements you use with your hands. I enjoy TIG welding but don't get to do it much these days. My old Miller is a beast and will weld a lot more items than it's owner!
David from jax

 

[bdhsfz6]

If you can braze with a torch, it is a good step towards being able to TIG weld. They are similar in the movements you use with your hands. I enjoy TIG welding but don't get to do it much these days. My old Miller is a beast and will weld a lot more items than it's owner!
David from jax

I do braze with a torch but mostly with brass or bronze. I didn't realize it could be done with aluminum.

Pre heating the parts is sometimes a problem though depending on the work.

 

[Langanobob]

I do braze with a torch but mostly with brass or bronze. I didn't realize it could be done with aluminum.

Pre heating the parts is sometimes a problem though depending on the work.

The torch “brazing” rod is some sort of zinc alloy. As Tinhack mentioned, it works OK for non-critical stuff. You can also gas weld aluminum with an oxyacetylene torch, aluminum mig wire and the right flux. It takes some practice to keep from melting your base metal into a gob but when it’s working it works pretty good.