View Full Version : Torch Welding Aluminumn?

08-08-2008, 01:26 AM
Is this a good way to join aluminumn? I am planning to build a Hull of sorts and am either going to rivet everything together (useing 70 series aluminumn) or weld using 50 series. I am considering using a torch for some of the joints. what do you pros recomend ? Thanx Mike

08-08-2008, 03:50 AM
Thats how they did it before tig. You will need special glasses among other things. Tough to do.

08-08-2008, 06:41 AM
As with TIG and most things its prep and cleanliness. Practice,practice and practice. Stainless Steel brushes. I haven't did much but the goggles with the correct colored lenses do help.

Go th the Henrob site, They had some videos on the torch and welding aluminum. https://cobratorches.com/

He also has the goggles that let you see the puddle and melted metal better.

You can rent the tinman tech gas welding of aluminum video at smartflix. http://smartflix.com/

08-08-2008, 07:46 AM
Mike..if this is for your boat hull... prolly a lot of welding right?
I'd suggest this is not the best idea.
Gas welding aluminum is a hard thing to learn. You'll make a lot of scrap before you get it right.
It is nice once you get the hang of it but it has it's downfalls...that why you seldom see it anymore.
#1 pain... you HAVE to use "brush on" flux...that HAS to be removed after welding or it can eat the aluminum. Not a big deal if the welds are accessible, but if they aren't you are in trouble. The only way to get that stuff off is with a nylon brush and hot soapy water.
#2 pain...it is a very slow process and the metal around the weld gets really frikkin hot if your doing any long welds. Burnt forearms and elbows...I'm not kidding. And...you get a lot of warpage from all that extra heat on long welds.
You need really accurate regulators because you use very low pressures. Yup...anyone can get low pressures with any reg...just try to do it twice so you are consistant....that's the tough part.
You need a very low and soft gas delivery. If you don't have that the flame "pressure" with actually blow the molten metal out of the puddle. It doesn't take much.
You have to coat both sides of the weld joint and the rod with the flux. Fluxing the rod is a pain also. I use two smaller rods....twist them together very tight then apply the flux. This holds the flux much better.
Another pitfall...if you get some rod that's a bit old...you have to be very religious about removing the oxides. Gas welding is very fussy about the presence of oxides.
And you do need the special lenses. That's the reason i quit gas welding alu. The only lenses I could get at the time where the ones for the small round lens goggles. I need glasses now so they don't work over the glasses.
I believe you can get the square lenses now that will fit over glasses.

08-08-2008, 07:57 AM
OK.. I just watched the Henrob demo video. That weld he did... was not really a very nice weld compared to tig. He got the same drop through I was getting if I wasn't really careful.... he called it 100% penetration...true but it was ugly. He goes pretty fast...he had to....the puddle was dropping through like crazy. Good thing he stopped when he did or it may have fell on the floor.:D
I was really impressed how that little torch cut the aluminum tho...never seen that before...well on purpose anyway.

08-08-2008, 12:35 PM
I use GTAW and GMAW on Aluminum but sometimes need something a little more friendly.Check out www.aluminumrepair.com, or www.durafix.com and see their welding wires and techniques on Aluminum. I use the kind of rod they are showing but mines from Washington Alloys. They are all kinda the same. Melt point is 720 degrees, can use map gas to keep heat and distortion low. Would refer to their Tech Engineers to be sure your application is safe as this stuff is more brittle than the base Aluminum. Easy to use though. search www.youtube.com and watch them make repairs using this stuff. Hope this helps.

08-09-2008, 02:17 PM

I posted this elsewhere but ... tried using this rod today. Just screwing around. I've never seen it before (not that it means anything).


The rod ...

Aladdin Products


I'm quite sure with a little (and I mean little) practice you could make a nice looking weld. This was my first shot ... yes I can do better.


08-11-2008, 05:46 AM
Has anyone used?
HTS-2000. Aluminum Brazing Rods.
HTS-528. Cast Iron Repair Rods.
As advertised on; www.aluminumrepair.com

08-11-2008, 12:21 PM
I have never used the HTS stuff but they have demos all over youtube and I will say that with any of these particular types of rods they are pretty much the same. I have been using the Washington Alloys brand and it pretty much does what they say. I posed the question of its use and history to Frank Armao with the Practical welding magazine and here is what he said--

This stuff has been around for 30 years that I'm aware of and has been sold under hundreds of brand names, including the 2 you mention. I've used it a number of times and I have some in the cabinet right now. These alloys are all simple alloys of 95% Zn, 5%Al, sometimes with 1% Mg and 3% Cu added. No matter what brand you buy, it is virtually all made by Ney Metals in Brooklyn, NY. They call it Ney 380. In fact, if you want to save yourself some money, buy it directly from them. Check out their website, www.neymetals.com, for a good ezplanation of how to use it and what it is.

Let's also correct a few misunderstandings. This filler does not produce a weld. It makes a soldered joint. It works because aluminum forms low melting intermetallic compounds with most other metals, including Zn and Cu. You rub the tip of the rod in the joint to scratch through the aluminum oxide on the surface. When the filler and the base metal get hot enough to form the intermetallic compounds (around 700F if I recall) the filller flows and you get a soldered joint. However, the joint is most definitely NOT stronger than the aluminum and has almost no ductility.
Don't get me wrong. This stuff works and is great in the right application. If you have sheet metal to repair, by all means use it. However, do not use it for structural or piping joints and absolutely don't look at it for
thicker material or as a universal filler metal for aluminum. It isn't . As I said, this stuff has been around for over 30 years and it hasn't replaced TIG or MIG welding in that time. It won't replace them in the future, either.

By the way, I think this is a very good question. If you don't mind, I plan
to use it as the basis for a future column. Thanks for the input


Frank Armao
Chairman, AWS Structural Aluminum Subcommittee

08-12-2008, 01:47 PM
Is this a good way to join aluminumn? I am planning to build a Hull of sorts and am either going to rivet everything together (useing 70 series aluminumn) or weld using 50 series. I am considering using a torch for some of the joints. what do you pros recomend ? Thanx Mike

Why not get a good MIG welder, and a spool gun? And again as other have said here, clean as much as you can. I used acetone, stainless steel brush and acetone again. Don't let it set to long after cleaning.

Or a good water cooled TIG torch set up, same about cleaning.

Michael Moore
08-12-2008, 01:58 PM
I got my goggles and flux from Kent White at TM Technologies (http://tinmantech.com/html/aluminum_welding_supplies.php).

I used the torch to weld up a water tank for my TIG from 1/8" plate. It worked well, was pretty straight forward (.032" AL sheet is a different matter!) and I had zero leaks in the 9 feet of bead.

Gas welding seems to have less problem with the weld cracking when you are shaping sheet aluminum. TIG is great for lots of other AL welding. As with many things you need to pick the proper technique for the job.


03-18-2013, 08:08 AM
gas welding alum is a verry bad idea on an alum boat hull, dont wast your time, tig or rivets, probaly too thin for mig spool gun. i have over 40 years professional welding and taught welding at community college for 7 years,