View Full Version : o/a welding aluminum
07-10-2006, 05:07 PM
I got Kent Whites lens, flux , and video and have been burning gas and turning scrap aluminum into scrap with holes and ugly looking welds.
My question is this how important is the alloy? Kent says 1100 or 3303 weld well. The only marking on this metal I have is asm-b209
I can weld steel with o/a and make it look good. I can tig steel and aluminum and make it look good.
The welds i am getting o/a welding aluminum are very poor looking and have holes well I will say not good. With 5- 6 hours of practice the welds are better but not good at all.
Can it be its just that hard to weld aluminum with the o/a tourch or do I have a alloy that isnt weld frendley ,,but it tig welds well.
I watched the tape the first time I said to my self Kent makes this look too easy I bet it isnt,,,for me right now I am fustrated I hope its not just a plane case of LOT ( Lack Of Tallent )
07-10-2006, 07:15 PM
I can relate, but here are a few suggestions:
- the metal must be very clean. Wire brush or scotchbrite then wipe with alcohol. This includes your filler rod. Oxides start reforming on cleaned surfaces almost immediately, so keep that in mind as you go, and reclean frequently. Keeping oxides out of the weld puddle will help you to weld quicker and hotter with better results. Once oxides get into the puddle it gets much harder to save the weld. Use plenty of flux, mix it with distilled water or ethyl rubbing alcohol if it is in the powdered form. Keep the flame neutral to very slightly carburizing. Sometimes if the hot and fast approach doesn't work, try "pulsing" the torch in and out, letting the puddle heat and cool but keeping the puddle in the outer flame envelope always.
Alloy is important as well since there are definately some not recommended for welding. 1100, 3003, 5052, 6061 will weld. I am unfamiliar with b209. I learned from Kent but still needed to pull hair out before it started to work well for me. I found it had a lot do do with developing a rhythym with both hands and getting the heat right. Hope this helps -Mark
07-10-2006, 07:37 PM
I have been there. I spent months melting holes in aluminum, until I bought Kent's video. Then my weld quality went up fast. High enough that my highly polished aluminum sculpture piece, fabricated from six sections of .050 aluminum, shows no signs of having been welded. (That said, I am still no expert. Kent is the expert.)
You probably need to cut your torch way down. And move the torch back off the weld when it is getting too hot, the way Kent does in the video. Another thing I do that helps is to use strips of copper to back up the weld. I do that a lot with all types of sheet metal. (I know, somehow it seems like cheating, but until I get as good as Kent, I have to do anything I can that gives me a decent weld.)
Get yourself some 1100 or 3003 to learn on. It's hard enough with that. If you can't find any around your town I'll mail you some. I assume any aluminum I can't identify is 6061. There is so much of it around, odds are good that that's what it is. Everything else is kind of rare.
07-10-2006, 09:06 PM
Your asm-B210 (actually it's ASTM-B209) is a Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate. See:http://www.principalmetals.com/specifications/astm-asme.htm
It does not tell you what alloy you have but 6061 will gas weld just as well as 3003. Regardless, gas welding AL can be a challenge. OA of AL will generally be used to butt weld body panels, so get a few sq feet of .060 or 3003 and cut into different sized pieces and butt weld them back together. Once you can see the puddle well, it's really just a matter of heat/torch control.
I don't gas weld AL anymore because for me, the flux is just so difficult to get totally get rid of. But I found that gas welding AL easier than Tiging it.
Either way, welding thin AL is never real easy. Good luck.
07-11-2006, 11:36 AM
Thanks for your help and encougerment!
This morning I got out the wire wheel on the grinder and cleaned the metal.
Then I sheared off a strip and s/s wire brushed the weld aera clamped fluxed tacked
Then fluxed again both sides and welded the parts together I had a lot more controll over the puddle,,It still looks bad but much easyer with clean metal.
Maybe with new materal and another hundred or more hours of pratice it will look good.
Can a tig welded part be hammered in to shape and wheeled ect or is this the way to do that?
07-11-2006, 12:38 PM
They say to do the job properly you should only use the stainless steel wire brush not a steel one. You should be able to planish and wheel a tig weld.
07-11-2006, 02:18 PM
They say to do the job properly you should only use the stainless steel wire brush not a steel one.
Yes I know. In my fustration I did that and was surprised with the results.
The materal I have been useing needed a good cleaning and just the s/s brush by hand wasnt getting the job done.
Now I am wondering if a s/s cup brush is available on a 5/8 grinder shaft I bet it is.
I have gotten a couple of inch spots that look good,, thats out of 4 ft of welding but the holes are getting less :smile:
07-11-2006, 03:32 PM
I have never seen an OA AL weld that looked anything like a good Tig weld. If your joining body panels that will be metal finished, then what your shooting for is a good penitrating weld that is slightly proud. It doesn't have to look pretty. :grin:
07-11-2006, 05:07 PM
Good luck Joe,
I hope you succeed where I have failed.
Despite having the help of a welding god I can't get the hang of it. Great top, rubbish penetration, or the other way round. Never good both sides.
To start with I used too much flux. This "glows" and spoils the view of the molten metal. It's surprising how little flux is needed.
Anyway, I've given up and bought a Miller Dynasty and should have done so in the first place.
Crushed a few test pieces through the wheel and the results are super. A light file and a rub with wet & dry and roll on my Lotus nose cone.
All the best,
07-11-2006, 06:30 PM
The one thing I did that I forgot to say is I used hot water for the flux .I got a lot more water in the mix than I had been useing but it mixed well so I thought I would give it a try. just like that! ,, it works better, not so strong. Just like you said with out the flair up ya can see a lot better.
welded another 6 hrs today, I got a foot or more of good weld,, out of many feet of welding.
Thanks all for your input :grin:
07-11-2006, 07:17 PM
Most welding supply places have stainless cup brushes with a 5/8 - 11 thread. That's pretty heavy duty action for aluminum. I use little two and three inch stainless brush wheels, made by Weiler, on a die grinder. If no die grinder, then an electric drill will do. I get them from McMaster Carr on the internet. They ship the same day.
Also I use those two inch Rol-Loc sanding disks a lot, in a die grinder, to prep for welds.
07-11-2006, 09:22 PM
Joe you are using a special lens right? There should be no flair visible from the flux with these lens. I have a Kent White lens, and one that is much cheaper. I bought them both from Henrob Jim, and I can't tell much difference between them. Even the "blue film" between the lens works well for the flair.
If you want to see a pretty OA aluminum weld you need to come to MetalMeet and watch Jim. I told him that it looked easy , he handed me the torch, and the 1st bead with his torch looked as good as any tig bead I've ever made.
Aluminum flux, correct lens and the right torch set correctly Ijust cannot get time to practice somine still suffer...........john
07-12-2006, 05:19 AM
Having the torch set right is paramount, the lens is as important and this is where the Henrob/DHC 2000 excells as the flame pressure is about 80 % less than a regular torch.
Making the weld look like a Tig weld is not that hard on the thin stuff.
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