TheSamba.com :: View topic - what welding equipment for aluminum heads

Fri Jul 11, 2014 8:38 am

I want to do some welding on some type iv heads I have. What do folks typically use? I see that MIG, arc-stick and TIG can be used. Is 1 better than the other? how? I will be pre-heating the cleaned heads in an oven beforehand.

Fri Jul 11, 2014 8:44 am

TIG is the way to go. You need a lot of heat with aluminum because it dissipates fast. Also cast aluminum is difficult to learn on. Plan on practicing on a junk head first.

Fri Jul 11, 2014 8:55 am

volkaholic1 wrote: I want to do some welding on some type iv heads I have. What do folks typically use? I see that MIG, arc-stick and TIG can be used. Is 1 better than the other? how? I will be pre-heating the cleaned heads in an oven beforehand.

Tig is the only way if your serious about learning to weld aluminum and especially on used vw heads , you will need to blast them to get them nice and clean and to burn out all the old contaminates , pre-heat is always good , aluminum dissipates heat quick so it takes a little to get them up too temp so they will weld up good .. also you need a good size welder , my personal beast is a miller sincrowave 250 with a small hw-20 water cooled torch , I have been beating on this animal for like 20 years .. its a work horse.

Fri Jul 11, 2014 9:03 am

You can Gas weld aluminum if you have the right flux and goggles, the nice thing about gas welding is it keeps the heat up as your are welding and does not produce a hard weld. Gas welding also burns up most of the contaminants so you get a cleaner weld.
One thing you should have if you are going to weld on heads is a good hot plate with a piece of 1/4" aluminum about 12" square to pre-heat the head, just set it on high heat and set the head on it and it will be hot in about 1/2 an hour.

Casey

Fri Jul 11, 2014 10:33 am

TIG.... Its about 300% better than any other solution offered.... IF you are not TIG familiar/capable, have work done commercially for you its cheaper and no learning curve....

Dale

Fri Jul 11, 2014 12:07 pm

You need a big power source to run the big machine. 50 amp 240 volt.

We have a Thermal Arc Tigwave 250 and a water cooled torch. The machine weighs about half a ton.

s

Fri Jul 11, 2014 12:19 pm

yeah, I know a guy with a TIG, seems like it makes more sense to pay him to do it than to invest in a bunch of equipment for a maybe 1 time project.

Fri Jul 11, 2014 12:25 pm

volkaholic1 wrote: yeah, I know a guy with a TIG, seems like it makes more sense to pay him to do it than to invest in a bunch of equipment for a maybe 1 time project.

Oh , if its a one time deal then yeah , doesn't make sense to invest all that money , my set up was like 4,500 20 years ago . but its paid for itself 20 times over ..

Fri Jul 11, 2014 12:43 pm

These Type 4 exhaust stud bosses on my head were cracked off. A local machine shop preheated, tig welded, and machined them back to their original shape. Pretty slick.

Fri Jul 11, 2014 1:40 pm

you need a TIG welder with AC capabilities, and you need something that will be capable of throwing approx 100A continues.

Since i bought my TIG welder, i just dont see any point of prepping any one of my other MIG nor ARC welders.

Fri Jul 11, 2014 1:55 pm

ravivos wrote: you need a TIG welder with AC capabilities, and you need something that will be capable of throwing approx 100A continues.

Since i bought my TIG welder, i just dont see any point of prepping any one of my other MIG nor ARC welders.

I would think you would need around 300 amps or more to tig weld aluminum cylinder heads. With aluminum, its around 1 amp per thou because aluminum absorbs heat so readily. Preheating the heads would lower this figure.

Fri Jul 11, 2014 2:03 pm

Northof49 wrote: ravivos wrote: you need a TIG welder with AC capabilities, and you need something that will be capable of throwing approx 100A continues.

Since i bought my TIG welder, i just dont see any point of prepping any one of my other MIG nor ARC welders.

I would think you would need around 300 amps or more to tig weld aluminum cylinder heads. With aluminum, its around 1 amp per thou because aluminum absorbs heat so readily. Preheating the heads would lower this figure.

Very true , mine will put out 300 amps and sometimes it feels like its using every bit of it but the trick is pre-heat .. any big chunk of aluminum can be tricky . but as soon as you get it hot it welds like butter ..

Fri Jul 11, 2014 7:14 pm

I second the recommendation for pre heating the part, It will be less likely to warp this way also. I recently moved from an old Miller Synchrowave 250 to this Thermal Arc 186
http://victortechnologies.com/index.php/thermalarc...power.html
Even though on by the numbers it's a smaller welder, it walks circles around the old Miller. Preheating the part, I have been practicing on heads and cases (Magnesium filler rod is expensive!!!$$$) and the 186 will easily get hotter than needed. And it's 50 lbs!
Really though, any good tig machine with high frequency start should do the job. Clean, clean, clean..

Fri Jul 11, 2014 8:07 pm

I only have a dryer outlet (240v/30a) powered 165 amp Miller Diversion, I weld heads all the time. Same sort of repairs as vanapplebomb. Trick is preheating, or using an argon/helum mixed gas. The helium easily adds 30 amps or so in apparent welding power to any machine, so my little 165 amp hobby welder acts more like a 200 amp machine. WARNING: helium is expensive! :shock:

I would not use any process but TIG for heads. Unless you have to fill a whole lot of material into the chamber and you're going to reshape it after, then you might be able to spool gun a bunch of stuff in there- but it would be far from ideal.

Fri Jul 11, 2014 8:58 pm

Tig is ideal. Mig will suffice. While generally its advised to preheat and post heat all metallurgically joined materials, aluminum is in a ballpark of its own. Both heat treatable and non-heat treatable alloys of aluminum become annealed when heated. The difference between the two is that the heat treatable alloys can have their mechanical properties restored by artificial aging(post weld heat treating).

Fri Jul 11, 2014 9:07 pm

oh, and i almost forgot, whether mig or tig, if your looking to heat thicker pieces of aluminum, helium boasts far greater thermal conductivity than argon. you're welcome

Fri Jul 11, 2014 10:48 pm

200+ amp Tig is what everybody uses. The arc rods work well too for spot repairs, but are $$$.

I'd love to hear some advice about mig welding aluminum castings.

The two times I tried it were so bad I never tried it again. :shock:

Sat Jul 12, 2014 12:13 am

Maybe you should try welding aluminum first. Up here at the college you can pay for time in a welding booth. You may deciede not to attempt welding aluminum head.

Aluminum is something else to weld. I wouldn't mig weld it for heads. I don't see why you couldn't I suppose.

Here's a good article about tig welding alum heads.
http://www.lincolnelectric.com/en-us/support/application-stories/Pages/engine-head-weld-repairs.aspx

Sat Jul 12, 2014 6:57 am

Problem with wire feeding aluminum is it's messy (spatters sometimes), metal deposition is often unreliable and it will not tolerate any impurities in the parent metal just like TIG. It's also a very HOT process, because if you're doing it right you'll be in spray arc mode. I would not use it on anything less than 1/4" thick pieces of aluminum, or you'll likely burn right through. Ask me how I know. That means for MIG, you're probably limited to the combustion chamber and the areas around the ports where the most meat is. Cooling fins and thinner areas? Forget about it, you will have no choice but to TIG.

Sat Jul 12, 2014 2:05 pm

There have been several advances in mig welding technology, the most prominent being in the application of pulse mig. Only problem is, the equipment that performs this process isn't really financially practical for the at home do it yourselfer(probably everyone reading this). I worked at an aluminum extrusion plant for 3 years. They had bought the miller Alumafeed set up... HANDS DOWN the best, cleanest way to mig aluminum. I'm talking TIG quality and appearance with no spatter on materials thick and thin. Even the inspector couldn't tell which weld process was used. Only thing is, that set up starts at $10,000. So again, not really a practical option for most of us. But the technology is out there.