Gas welding Aluminium.

[Moving molecules .]

Hi Gents, have done a bit of gas welding on a 1958 Aston Martin because it’s a softer weld ( which penetrates straight through ) and was period correct .....what’s your experience with it ? , Fluxes, Eye protection , welding equipment , torch makes Etc.
It all helps out on this tricky welding material .

cheers Matt from U.K.

[cliffrod]

Eye protection- it's hard (impossible?) to beat TM Technologies TM2000 lens developed specifically for gas welding aluminum to both protect your eyes from flux glare and properly see the weld puddle. I've had mine for almost 20 years and it's great. I also regularly use it for welding steel.

Welding Torch- some experts whom I respect very much have said to me that the Meco Midget N is the best torch they've ever used. TM Technologies also sells and supports this torch with a full complement of supplies and accessories. Other torches work fine, but as they cycle out of production they become less practical to keep in service.

A Gas Saver shut off valve is beneficial, especially for work requiring significant manipulation of the workpiece during the process. Haven't added a piezio igniter yet to use instead of the pilot flame, but plan to at some point. Both conserve time and welding gases.

I need lots more practice but have found that setting pressure using a vacuum/pressure gauge (hose installed over torch tip & adjusted with regulator) allows a much better welding experience than trying to use the gauges on regulators alone.

[Chazza]

Have you any photos of the pressure gauge on the tip Cliffy?

[kenc]

Well, I know Peter won't agree about the Meco Midget. I can't weld like Peter, but I agree with him that the flame is very harsh on the Midget. Perhaps due to the diminutive size of the chamber? Who knows? However, the Meco Aviator-Jet is a marvelous tool Sadly, no longer made but available on ebay now and again.

I have a couple of Meco Midgets, a new TM technologies sourced one, and an original Meco - they both act the same. Kent White even sent me a couple of experimental tips that were supposed to be improved, but they weren't much.

[kenc]

Other torches work fine, but as they cycle out of production they become less practical to keep in service.

.

Not sure I agree with this. I have - and have had - many torches, some a good 50-60 years old and have never had any reliability problems. I've heard complaints about the Aviator Jet seals but I reckon most of these complaints are just parroted by folks who have never owned one, since I own two Jets, neither of which is a youngster and they both function great. Have a few Harris 50s, a Smith AW1A and a few other, none have given any problems. A torch is a pretty simple item really.

[cliffrod]

I didn't say anything about reliability. If you have a complete torch, with all the tips (for example) that you'll ever need you're golden. If not, you're not.

My personal experience is being very happy with my concoa 750 kit that I bought new 25 yrs ago and used to learn to weld. Around the time it went out of production and I needed tips I didn't have (that didn't cost stupid money at the time) I got a brand new Purox w300 kit. After it went out of production and I needed tips that I didn't have.... This is the point I was making.

Yes, you can watch the Internet and buy nos tips for out of production torches when they can be sourced or hope used tips you find aren't junk. that's ok for a hobbyist but not a practical or timely approach for a work schedule. Good or bad, a Meco Midget is one of the very few that's still available new, well-supported and performs at an acceptable level. It wasn't designed to be an aviaton-grade torch but the ones that were are nla.

I like my concoa 750 very much. It's not an aviator-style torch, knobs are easy to bump, etc but it's the torch I prefer until I buy something like a Meco Midget. Depending upon an obsolete torch (like I do now) is a personal choice. IMHO it's probably not the best option for many people, especially a new person on a budget.

[Peter Tommasini]

Well, I know Peter won't agree about the Meco Midget. I can't weld like Peter, but I agree with him that the flame is very harsh on the Midget. Perhaps due to the diminutive size of the chamber? Who knows? However, the Meco Aviator-Jet is a marvelous tool Sadly, no longer made but available on ebay now and again.

I have a couple of Meco Midgets, a new TM technologies sourced one, and an original Meco - they both act the same. Kent White even sent me a couple of experimental tips that were supposed to be improved, but they weren't much.

Ken ,with the right tip (the old type ) the Meco Midget is quite good . As far as I can see the hole on the new tips is the problem , after studying the new tips I believe that the hole should be tapered from the inside and not straight true
Peter T.

[cliffrod]

Charlie- here's a couple of pics. It's not my idea but works well for m






It's much easier to read this plain engine vacuum/fuel pressure gauge that only ranges up to 7 psi than the much less definitive gauges, especially the oxygen. Slip the hose over the torch tip, open the respective valve on the torch and adjust the regulator by this pressure gauge instead of gauge on the regulator. Then close torch valve, disconnect hose to relieve pressures and repeat with the other tank. At 3-4 psi, the standard oxygen regulator gauge barely moves if it moves at all.

But when the line pressures are set accurately like this, there's even fewer reasons for a bad weld. And i still have undesireable welds. It couldn't be the operator, could it?...

[Chazza]

Thanks Cliffy. What a good idea!

[Chris_Hamilton]

Setting up the torch correctly doesn't even require you looking at the gauges. If you have Kent's video Gas Welding Aluminum "The Difficult" Part 1, he shows the proper way to set it up. Same way Peter did at the class I attended.

Open your tanks, back off both regulators completely, open your torch all the way, both the oxy and the acetylene. Hold the torch next to your cheek, gradually open the acetylen regulator until you feel a puff against your cheek. Light the torch (not against your cheek) Continue upping the pressure of the acetylene regulator till it burns clean. Gradually start adding oxygen with your regulator. Add more acetylene, then more oxygen until you don't see anymore increase. Now gradually run in your valves on the torch down to the size of the flame you want. Done.

[sparky]

Setting up the torch correctly doesn't even require you looking at the gauges. If you have Kent's video Gas Welding Aluminum "The Difficult" Part 1, he shows the proper way to set it up. Same way Peter did at the class I attended.

Open your tanks, back off both regulators completely, open your torch all the way, both the oxy and the acetylene. Hold the torch next to your cheek, gradually open the acetylen regulator until you feel a puff against your cheek. Light the torch (not against your cheek) Continue upping the pressure of the acetylene regulator till it burns clean. Gradually start adding oxygen with your regulator. Add more acetylene, then more oxygen until you don't see anymore increase. Now gradually run in your valves on the torch down to the size of the flame you want. Done.

Ha Ha... You wont find this this little tip in the safety manuals.😋

[cliffrod]

Setting up the torch correctly doesn't even require you looking at the gauges. If you have Kent's video Gas Welding Aluminum "The Difficult" Part 1, he shows the proper way to set it up. Same way Peter did at the class I attended.

Open your tanks, back off both regulators completely, open your torch all the way, both the oxy and the acetylene. Hold the torch next to your cheek, gradually open the acetylen regulator until you feel a puff against your cheek. Light the torch (not against your cheek) Continue upping the pressure of the acetylene regulator till it burns clean. Gradually start adding oxygen with your regulator. Add more acetylene, then more oxygen until you don't see anymore increase. Now gradually run in your valves on the torch down to the size of the flame you want. Done.

No videos or DVDs here. No matter, I'm 99.9% certain Kent is the one who suggested (over on AMS) using a pressure gauge like this. so I hung a spare one on my cart and do it that way.

Really can't remember if Peter suggested the cheek method when I took his class. It was more about wheeling.

[Moving molecules .]

Does any one like the Henrob or Cobra... it’s a funny looking thing ...but Does it work.
All very Expensive for me to buy from the US.
need to buy something for are new company... so need some ideas.
Used a old school torch in my old place sadly NLA.

[Bill Tromblay]

Hi,

I have the Henrob, and it is ok. The aluminum handles make it heavy and the pistol grip works great for a pistol, but not so much for welding. I use mine for Oxy/Acetylene welding and it works fine, but I prefer the Meco Midget.

Setting of pressures to your cheek and my year and half learning curve.... 😩 Short back story on my knowledge. I received certification for Aerospace welding with the use of Tig, steel and aluminum. I think I weld relatively Ok. Others can weld nicer, but I get the job done that is Airworthy. I think I understand the concept of gluing two pieces of material together with a weld. So, I decided to learn something new and go the Oxy/Hydrogen gas welding route as used by the aircraft company's of WW2. I bought the all the stuff new, gauges, hoses, Meco Torch, flux and on and on. I ordered the videos and every book I could find on the subject and sat down with a bowl of pop corn and watched away. "The trick" you don't need to use the gauges, turn up the regulators until you feel it on your cheek and go as described above. Great, off to the races.... The reg's that I bought had 0-150psi gauges installed, as you turn up the pressure and feel it on my cheek, it wouldn't move the needle off the peg, (but that is ok, because I have this trick).

Unknown to me at the time. When I would weld, a scab of aluminum would form over the weld (like you see on a casserole or on brown gravy) and the heat was extremely hot ( i'm going down in tip sizes from the recommended sizes). I would weld so fast, I had to use 1/8" dia rod, because I couldn't feed fast enough. The weld bead would look beautiful on the bottom, but the top would look like grains of salt,, stuck in the weld. No matter what I did, I couldn't make it go away. Leak checks, filters, different operator, different gas, same result. I consulted with above and others... The issue was "me" or "bad technique" or "what do you expect" or "fix your equipment (even though it was bought new from a guy in California)". But I didn't give up and I tried and tried and tried, varied my techniques, and equipment and no matter what I did, I would get the exact same result. One thing was for sure, no matter what I did or varied, I would get the exact same result (guess I had more skill than I thought).

Then..... One Saturday morning I log into Facebook and a guy by the name of Solice metal works is Oxy/Hydrogen gas welding some aluminum fenders together with the most beautiful work and beads you can imagine. I quick welded a test bead, still crap... Take a picture send it to him in a message and wait for a response. He writes back 5 min later with one question "what pressure are you running at??" Hmmm...??? I removed the 0-150psi gauge and installed a 0-15psi gauge that I had laying around. Opened the regulators and the torch and looked at the pressure. Alcoa, Reynolds Aluminum, Kent Whites booklets and videos, WW2 welding manuals all state that Oxy/Hydrogen welding should be set at 2psi Oxygen, 1psi Hydrogen. My highly calibrated cheek is set at 10 psi.... After wetting my pants, I turned down the both regulators to 2psi and 1psi respectively and proceeded to weld the most perfect, beautiful, wonderful, joyful weld that I have ever seen... Wetting my pants again on the process...

The scab and crystallizing of the weld pool was caused by oxidizing the living F#^& out of the weld, because the pressures were so high. It took a year and a half to finally figure out the problem and was by far one of the hardest things I ever learned. I have since bought overhauled two stage regulators with low tension diaphragm springs and low pressure gauges. The repair shop specially set them up for low pressure work.

Tricks and short cuts are great, but only once you learn the fundamentals. Every one says you have to move when you gas weld or you will blow holes, not true with the right equipment. I can gas weld .025" thick 3003 with no holes. Holes can still happen, but nothing like you see in the training videos that are out there.

Hope it helps someone save the time I invested, by some not so go advice.

Bill

[Chazza]

Great advice Bill!

So the puff on the cheek did not work for you?

I have tried the cheek method and the normal regulators, but not the method Cliffy uses,

Cheers Charlie

[Bill Tromblay]

Hi,

I was thinking and this may be a possibility. The cheek method may work with oxy/Acetylene, even though the welding books recommend the same low pressures. But I do know that does not work with Oxy / Hydrogen. I haven't come up with a reason as to "why" one and not the other, just my experience. Kent knows what he is doing and what he is talking about and I know the cheek method works for him with acetylene.

B

[joeswamp]

Hey Bill -- Are you saying that you were oxidizing the weld because your oxygen was set too high, or are you saying that both pressures were set too high? If it's the latter (and you were putting too much heat into the weld), doesn't that mean the length of the innermost cone would have been too long? I thought that the little inner cone length was really the critical factor, as it correlates well with gas flow. This is assuming the flame is close to neutral.

Maybe these are dumb questions as I've never tried oxy-hydrogen welding, I've heard you can't really see the flame and so I have no idea how you would adjust it. The flame is cooler so I'd expect you could go a little slower than with oxy-acetylene. I do know that a lot of people prefer it.

[Bill Tromblay]

Hi,

With the hydrogen unknowingly at 10 psi, I was running the oxygen (unknowingly) at the same pressure. The Oxygen needed to be that high, to create a cone. So even with high pressure, you can mix the gas to change the cone length, just as you can at 1 psi. The one thing i noticed with the higher pressure, you could go from a cold flame, to brutally hot, with a slight bump of the control valves on the torch. You had no fidelity with the controls. With the pressure now set correctly, I have a lot of control. One way I thought of explaining it, would be to turn up the TIG welder to full amperage than weld with it. Can you do it? Sure, but it isn't easy and will look bad.

I saw a picture today on-line of a Oxy/Acetylene gas weld on .063" 3003 aluminum and they had it set at 4 psi Oxygen and 4 psi Acetylene and their results had the same appearance as my welds. You can see the "salt crystal grains" appearance running thru the top of the weld and the bottom looks fine. As metal shaper's, most guys dont care about the appearance, because you grind the weld off or planish it into the surface. On most aircraft components, the welds were left visible, and caused my concern to solve the problem.

B