Welding aluminum??? Mig spool gun or go Tig?

[Russel Nash]

Hi all,

This would be for a "ladle" for a birdshot maker, so it really doesn't bear any weight or load.

I am using a steel ladle now that I welded up. It seems to me that all the commercial shotmakers use an aluminum ladle or pot to melt the lead in. It seems to me that aluminum is used because of its heat properties.

I already have a mig that I could outfit with a spool gun. I'd probably also have to switch the gas and maybe the polarity too.

A whole new tig machine sounds expensive... Plus there would be a learning curve with it.

[koehn,jim]

You have to switch the polarity and gas. I would stay with the mig unless you plan to do a lot of it. I am very happy with tig as it will handle many different jobs on cars. They are however a bit pricey to buy one, figure around a thousand dollars. Hope this helps just my opion.

[Shooter]

Spool guns are heavy. A TIG is more versatile. Pushing aluminum wire through a MIG lead can be done, but keep the lead straight, and expect feeding snarls.

P.S> Clean, clean, clean your work.

[375RUGER]

you don't have to get a spool gun. If you were going to do A LOT, I recommend a spool gun or the "special" kit they sell for aluminum.
I have a hobart handler and I run the Al wire from the machine. I keep the cable fairly straight. Makes a beautiful Al weld.
Use .035" wire.
Use Argon.
Run DC Electrode Positive same as solid steel wire.

[blademasterii]

Tig will make the best welds. It is however as stated an expensive investment. I am an aluminum welder fabricator by trade. Big heavy projects mig is great. Accurate and precise tig is the best.

[jmorris]

If you have never done either, MIG welding aluminum is harder to get good results than TIG welding. MIG is much faster but its just not as easy to get everything right as steel is and when you hit the button you really have to move.

TIG welding with a foot control for amps, lets you run at any speed.


You can also weld much thinner materials than you can with a MIG.

http://i664.photobucket.com/albums/vv5/qvideo/tig.jpg

[bearcove]

Just MIG it if you can run it on your machine. You will tend to get crater cracks but just grind them out and shoot a bead over them.

[zuke]

If it's just a one of job, why not pay someone else to do it?

[Jack Stanley]

jmorris ..... now that is impressive :grin:

Jack

[W.R.Buchanan]

+1 on the impressive. I can't do that!

Randy

[greywuuf]

Depending on the mig machine you have...changing the cable liner might be advisable as well, wound steel liners have a tendency to arc down the length and cause pitting and sticking on aluminum wire. Conversely non conductive liners can concentrate the current at the contract tip and create their own set of problems as well.

If you happen to have an old car alternator, you can do like I did and build a high frequency ripple dc tig welder. It really works best as a straight stick welder as I have yet to put a foot control on it.....but it was cheap!

homeland defense begins at home.

[shotman]

Back to your project
the reason for the aluminum shot maker is it is much cheaper to make and machine. Its NOT better its cheaper to make . The best is cast iron but it cost a lot more to make .
Once you use both you will see why

[Russel Nash]

Okay, thanks! ^^^^

The other idea I had in the back of my head was to build an aluminum tread plate dog box for my two weimaraners when we go hunting.

[Plate plinker]

+1 on the impressive. I can't do that!

Randy

What weld a coke to a dr pepper? I'd be more impressed with a coke to a Pepsi. :kidding:

[Russel Nash]

In a taste test, 9 out of 10 welders preferred Coke over Pepsi...

[hunter64]

I watched my brother weld an aluminum receiver mount step for the back of his truck with his ac/dc stick welder and aluminum rods. It actually didn't look to bad but my Tig would have been much better.

[John Taylor]

Always thought Mig for the heavy stuff and Tig for the thin light stuff. I used a mig spool gun on truck frames, fast and welds out of position. I have welded 1" aluminum with tig but it take 375 amps with 3/16 tungsten, max on the machine I had at the time. Little hard to weld pop can with a mig. Use AC for aluminum welding

[jmorris]

jmorris ..... now that is impressive It impressed me thus my suggestion of a TIG. You can control the heat so much better than any other method. Just another reason to get a new "toy", on your way to "one of everything", that allows you to do anything.

[Marvin S]

For smaller precision projects the Tungsten Inet Gas TIG process is the best. It allows quick change to ALL welding processes. Welding thick alum with a TIG welder requires lots of power and a heavy duty cycle. Think this out well and go to the AWS welding forum before you make a decision. The blue welders that say Miller on them are the best but also most expensive.
I may add some more on this in that transformer type TIG welders require mucho power to run them so keep that in mind. The inverter types such as the wonderful Miller dynasty's use about half but cost twice as much. You may look at the import Everlast machines. The Miller Syncrowave 200 is a good home welding machine but requires around a 70 amp breaker, it is what I use at home. You also need to think about air cooled and water cooled torches and the capabilities of the two and the cost to go either way. The inexpensive Harbor freight machines do not have an A/C high frequency setting and are only scratch start on D/C and do not have an amptrol. I have used one and they do weld steel pretty well.

[jmorris]

If you buy used you can save a ton of money. My largest Miller TIG is a syncrowave 350, can put out 375 amps with remote, water cooler, extra torches, two argon bottles and tons of extras ran $1000 even.

[JIMinPHX]

I have a fair amount of experience with both Mig & Tig on aluminum in a production environment. I'll give you the short version here. Tig makes it MUCH easier to get a good reliable weld on aluminum. Mig will allow you to move MUCH faster than Tig, but you need to have everything set up perfectly to get a good Mig weld on Aluminum. If you are planning to do less than 10 linear feet of bead, it is probably not worth the set up time to attempt Mig on aluminum in my opinion.

In general, aluminum needs about twice as much heat as steel of the same dimension. If you are going to run aluminum in a Mig machine, then you either need a spool gun or else a Teflon liner in your conduit.

If you just need to weld a few small parts, then you may wish to consider just paying a local welder to do the job for you. If you feel adventurous, you can also try aluminum rods on a stick welder. If you try that trick, preheat with a torch as much as possible.

[Russel Nash]

I've been working on my 3G the past two days. Where I am doing the test strictly forbids any grinding. Period!

This sucks!

It's on 3/8ths plate, beveled, 1/4 inch gap with backer plate.

I don't do any sitting down at work, ever, so sitting on a stool in the welding booth the past two days makes my buttocks hurt. I might steal a cushion from my other sofa, and take that with me in the morning.

[jmorris]

I've been working on my 3G the past two days. Where I am doing the test strictly forbids any grinding. Period! I almost never grind a TIG weld, maybe if its a cutting surface.

[Russel Nash]

whoops!

I forgot to mention this is just stick welding, 7018's.

I like the 3/32nds rods. Or I did because with that 1/4 inch gap I can actually see on either side of the rod, especially for the root pass.

This is what my instructor's welds look like:

http://i603.photobucket.com/albums/tt112/gryphon1994/5B913602-C525-41F1-A09F-33580ECADDDF-228-000000F8E433CF0C.jpg

And this what my last one looked like:

http://i603.photobucket.com/albums/tt112/gryphon1994/334ABAD0-A349-49C7-B115-2A36B01383B2-228-000000F8C02DC44A.jpg

ARrrrgghh!

This is weaving, not stringer beads.

For the actual test, The weld can't be any higher than 1/8th proud of the surface. Any undercutting can't be more than a 1/32nd.

Again, no grinding!

[Russel Nash]

A-HA!

I figured out what I was doing wrong.

Turn this pic on its side:http://www.eastwood.com/media/content/images/Eastwood-Stitch-Welder/19031Q-7.3.jpg

I was going too much in an arc motion, like an upside down U.

[JIMinPHX]

7018 is a high deposit rate, low penetration, high tensile rod. It is good for a top pass, but it is not the best choice for a root pass. You are better off using a high penetration rod like a 6010 or 6011 for the root pass & then topping with a higher deposit rod, like a 6013 for mild steel or a 7018 for higher tensile applications. Also, the high deposit rate rods generally don't like to be run very far out of position. The U motion works very well in some applications, but not in others. 3/32" rod is a little lite for 3/8" plate.

[jmorris]

If your "instructors" weld passes just run you rod right down the center fast enough not to build up more than 1/8" crown and you'll be good to go. Might try that anyway along with cranking up the heat a bit. A good stick weld will look the same as MIG once you have cleared the slag.

[jblee10]

For detailed work I alway prefer the Tig over Mig. Even on steel. But I really can't say. I have never used anything on aluminium other than Tig. Balling the tip of the tungsten is an art in itself, and something I don't think can be replicated with Mig.

[Russel Nash]

WOOO HOOO! I passed!

http://i603.photobucket.com/albums/tt112/gryphon1994/9FE3A8E7-D151-4813-AA1D-10DD96B95D7D-228-000002029BCA97AD.jpg

Here is a special tool that is used to make sure that the weld is not greater than an 1/8 proud of the plates.

http://i603.photobucket.com/albums/tt112/gryphon1994/44D4D27B-0A05-4EFC-9BF1-0E57C71CFC31-228-00000202F22D8693.jpg

Here is another tool used to check for undercutting which can't be more than 1/32nd:

http://i603.photobucket.com/albums/tt112/gryphon1994/5E077C7C-A3A1-4218-B4D1-CE0BCF6A9673-228-00000202CCDF0E78.jpg

LOOK MA! no pinholes. No slag inclusions:

http://i603.photobucket.com/albums/tt112/gryphon1994/FE9CE133-6C58-41FD-B894-1DF72ED22A54-228-00000203400AB26C.jpg

The instructor here is grinding the weld smooth (or the welding backer plate):

http://i603.photobucket.com/albums/tt112/gryphon1994/875DE2F9-C585-4B9C-8FB5-AA4F6EDAF946-228-000002035E6F4E87.jpg

The plate coupons are allowed to cool then placed in a hydraulic ram bending jig:

http://i603.photobucket.com/albums/tt112/gryphon1994/7ECAABEE-2051-4C85-A52A-1DC365C13043-228-0000020377899E64.jpg

http://i603.photobucket.com/albums/tt112/gryphon1994/9C717155-0998-4F33-9C5F-DEB44951B74F-228-000002038AEA193D.jpg

One "coupon" gets bent stretching the face of the weld. Then the other coupon gets bent the other way, where it stretches the back where the root pass is. No pinholes, no stress cracks when the were bent into a U shape:

http://i603.photobucket.com/albums/tt112/gryphon1994/33B9ECE5-7B04-4493-A053-9915AAB2A416-228-00000203A002C669.jpg

[theperfessor]

Good job! That's a pretty weld.

[Russel Nash]

I put everything into a public photobucket album, so that's why the above links are broken.

Try this:

http://s603.photobucket.com/albums/tt112/gryphon1994/3G%20Vertical%20Up%20Welding%20Test%20Three%20Eigh ts%20plate/?albumview=slideshow

Thanks Perfessor!

[oldred]

For Aluminum stick rod the trick is to run VERY short beads! Even just doing a series of tacks will yield a better weld than trying to run a long fillet bead like you would with a steel rod.

Also unless I missed it no one has yet mentioned the oldest method of welding Aluminum, an Oxy/Acetylene torch. Those stick rods for arc welding make darn good torch rods and already have the right flux on them, preparation with a stainless steel brush is the key to using a torch but a person can do a surprisingly good job with a gas welding rig. With practice both thin and heavy Aluminum can be welded by this method and although not quite as slick as TIG it can make a very presentable weld that is every bit as strong, I fabricated several boat gas tanks this way before I finally bought a TIG welder. An example of the strength of gas welding Aluminum is the many welds used on WWII aircraft, I looked at the gas welded wing tip skins on a P51 Mustang some years back at an air show and even from way back in '45 that darn thing almost looked like a TIG weld.

[Trifocals]

Yes, a spool gun (expensive) will do the job as will TIG (very expensive). However, if you are a reasonably proficient "stick" welder, aluminum stick welding rod can be obtained from any well stocked welding supply store. It works as well as the proficiency of the person doing the welding. I have used a spool gun as well as TIG and also "stick" rod. You will probably not get a pretty weld with stick, but it will be strong. A hand full of stick rod is a lot cheaper than purchasing a spool gun or a TIG welder. I would suggest you purchase several brands and variations of aluminum stick rod and see which you prefer. LOL :smile: Trifocals

[pipehand]

I have a little bit of experience in TIG welding Aluminum. A couple of tips-

1. High Frequency welding machine.

2. Make sure the metal to be welded is very clean and free of oxides. Grinding discs specifically for aluminum are available. The one you use for steel will clog up.

3. Do Not use the 2% Thoriated tungsten you use for welding carbon and stainless steel. Use only pure tungsten.

4. Do not sharpen the tungsten like you do for ss and carbon. Just let the electrode form its own ball when the arc starts.

5. Don't try to "walk the cup." You'll actually be "long-arcing" a bit, melting the parent metal, and dipping the filler wire into the puddle.

Going off a ten year old memory, but I hope its helpful.

[jmorris]

Destructive testing is a good way to know of a weld will fail but if your part is too expensive to ruin or too important to chance on "he can weld one part good", there are other methods to check each and every weld like sonic, die or X-ray.


Example part made of Inconel and stanless with hours of machine work for a hydrogen/natural gas burnner, gets all of them. 35 millon BTU out of this small one.


http://i664.photobucket.com/albums/vv5/qvideo/IMAG0126.jpg

[Marvin S]

There are so much better tungsten's out now than pure which will not take the heat well. Look at 1.5 and 2% percent Lanthanated, Zirconiated and Ceriated when run with straight helium will increase penetration with low power machines . And now the rare earth hybrid blue looks like a good way to go.

Just for a note not all aluminum is weldable as far as strength is concerned most notably are the so called aircraft grades of 2024 and 7075.

[JIMinPHX]

Also unless I missed it no one has yet mentioned the oldest method of welding Aluminum, an Oxy/Acetylene torch.

You must have a touch that I have yet to develop. I tried a torch on aluminum once. By the time that the metal got hot enough to melt, a large area just fell away from where I was trying to put the bead. I could not get the heat concentrated in a small enough area with a torch. It looks like I still have a few tricks to learn.

[oldred]

You must have a touch that I have yet to develop. I tried a torch on aluminum once. By the time that the metal got hot enough to melt, a large area just fell away from where I was trying to put the bead. I could not get the heat concentrated in a small enough area with a torch. It looks like I still have a few tricks to learn.

It's really not as hard as it might seem and just like any other process it's just a matter of practice. back in the late 60's and early 70's when I first started welding Oxy/acetylene welding of Aluminum was quite common and an accomplished welder could produce a bead that would rival a TIG weld in some situations. I am not saying torch welding Aluminum is as good a process as TIG, obviously it's not for several reasons, but a properly done torch weld is strong and done right it will look nice. One trick we did was to use a Cobalt blue lens which made visibility much better and thus it was a lot easier to see when the base metal was reaching the melting point, very fine line between just hot enough and having the base metal just collapse and fall away. Those stick rods make pretty good torch rods and already have the proper flux on them and in fact one brand, Forney I think, even suggests on the package they can be used this way. Base metal cleanliness and the proper flux so the filler can penetrate the oxidized layer and reach the puddle is the key to doing it successfully but once mastered it really becomes quite easy, just like torch welding steel however it's becoming a lost art.

[jmorris]

just like torch welding steel however it's becoming a lost art. Ahh the good old days when Dad wouldn't let me use his welder "waisting" electrodes and having to weld with oxy/act using coat hangers.


Agreed, good machines for other methods are so cheap now and the cost of gases higher, oxy/act has simply been replaced with other faster and better methods.

[JIMinPHX]

Ahh the good old days when Dad wouldn't let me use his welder "waisting" electrodes and having to weld with oxy/act using coat hangers.


...or bailing wire.

[oldred]

You guys are right about it being common to use both hanger wire (probably more DIY tail pipes welded with coat hanger than any other method!) and bailing wire but a good virgin alloy welding wire works so much better it's amazing. I too have used my share of coat hanger, and even mechanics tie wire, but true good quality welding wire from a welding supply will flow out a heck of a lot smoother with waaaaay less sparks and popping. Coat hanger, "bailing" wire, etc may be ok for an occasional tail pipe but should NEVER be used for anything that needs a quality weld, the stuff is not only of unknown alloy but it is made from scrap and contains all kinds of junk that can ruin a weld. When buying gas welding rod make sure it's a good quality certified welding alloy since a lot of the rods sold for this purpose are little more than copper coated coat hanger, all gas welding rods are not created the same! Cheap rods are a dead-give-away that they are junk, good quality rods start at about $5+ a lb but are worth every cent.

[jmorris]

but a good virgin alloy welding wire works so much better Yes, I haven't used coat hanger since I was a kid and its not as easy as using the correct filler material but it tought me how to weld. Sort of the same way I learned how to stick weld using rods that the flux had become wet and were so difficult to weld with my father didn't mind me using them to learn with. After a few years welding with them I took a welding class in highschool and welded several others coupons up I was so impressed with how easy it was, with good rod.

There was a time when folks didn't throw anything away, waisted little and made what you had work. Back then my father wouldn't want you to use his good welding gloves because they cost too much and "your skin will grow back".

[Russel Nash]

Destructive testing is a good way to know of a weld will fail but if your part is too expensive to ruin or too important to chance on "he can weld one part good", there are other methods to check each and every weld like sonic, die or X-ray.


Example part made of Inconel and stanless with hours of machine work for a hydrogen/natural gas burnner, gets all of them. 35 millon BTU out of this small one.


http://i664.photobucket.com/albums/vv5/qvideo/IMAG0126.jpg

What is that for?

A refinery?

[Russel Nash]

I am working on my 4G (overhead) now. I think I picked up some tips and tricks that I'll try tomorrow.

[401]

Oxy/Acetylene & Blue Cobalt glasses works pretty nice if you want to play with gas, however Oxy/Hydrogen with Pink Didymium glasses & Anti Borax #8 flux is the ticket for Aluminum welding with gas , just use an Oxy regulator with the connector to the tank changed to left hand thread (fuel), a cheap alternative and the way it was done back when before tig/mig.
Just throwing out some gas info, not really what the post asked though, just saw it mentioned so I floated that out there :)

[oldred]

I have used Hydrogen and thought about mentioning it but it's kind of usefulness limited so I stuck to the Oxy/Acetylene since it's so common and does work quite well. You point out something I hadn't thought of however and just for kicks I think I will research it to see what I can find, I mentioned Aircraft Aluminum welding back in the forties and I was "assuming" they used Acetylene because I didn't stop to think about it but I betcha it was Hydrogen.

[401]

oldred:
Yup, I do believe it was.
Its easyer to weld with , lower temp and all and you can see through the flame or lack of visable flame alot easier. As far as I know it is the only FAA approved method for welding an aluminum fuel tank. butt weld style, for things such as aerobatic aircraft other than the electric methods allowed, much cleaner then acetylene as well. Really the drawback vs electric is the heat distortion on large panels and the penetration on really thick material. For say a fuel tank, you do need to tack about every 2 inches because of the heat warping which is less evident with them "new fangled electronic gadgets" :) lol ( words from the fellow who taught me how to weld with dirigible fuel)
Nowadays tig/mig has gotten alot cheaper but in the 60's through 90's there were alot of people and various chapters over at the EAA and the rest of the aviation world who set up oxy/hydrogen setups to do what they needed done and it was cheaper and worked just fine.
Not sure of the cost differential anymore these days, but heck its an option and thats always nice to have, Like casting vs buying!

[oldred]

As far as cost have you priced Acetylene lately!!:holysheep


Hydrogen is almost free compared to Acetylene.