The problem with O-A welding aluminum is the aluminum oxide coating that forms on the surface of the aluminum. It has a higher melting point than the metal underneath. It's necessary to use a flux that melts at the exact temp of the under layer, and start feeding the fill rod as soon as the flux melts. Otherwise, by the time the oxide flows, the metal is a big puddle under it and it just falls away. It takes lots of practice to get a good bead with O-A and aluminum. TIG is the easiest way, but the metal has to be brushed shiny clean before you begin to take the oxide coating off. Jerry
Save up your pennies and get both! It's not so much a matter of which is better, as they both have advantages and disadvantages. O-A will 'eat your lunch' money-wise if you start doing frames, roll-bars, etc.. Brazing, heating & bending, and cutting are done easily with O-A. etc. etc. JG
The real reason people like using a TIG with aluminum, is that you don't have to spend hours washing and finding flux before you primer and paint. With OA on aluminum you need to use a flux, and it makes the job really easy and fast. TIG is much slower to weld, but there's no cleanup when your done. One thing you can do with OA though, is to braze and aneal. Two very important metalsmithing techniques. When building a closed aluminum tank (for instance) you can't (OA) weld it (but can TIG it) because you could never wash the flux out, but you could braze it together. The flux is a corrosive. Sadly, like all things, you need one of each MIG, TIG, OA, PLASMA CUTTER, Grinding Disc... Oh, and you'll need an aircraft torch, cutting attachment, Meco torch, and a Henrob/Dillon before your collection is complete.
I can't get my scanner to work, but i have a vintage Audell welders book with a lot of the aluminum torch welding tips and tricks in it. when i get it fixed i'll try to put some of it up,this is late 40's early fifties stuff.
The people use TIG is because everyone who is uninformed has gotten the impression that tig is intrinsically superior. lol It's not. It's just ANOTHER process. They are all good, and when done right, they all do the same thing.... fuse metals. If you know what you're doing there's no reason a wirefeed welder is sub par compared to TIG.
If you are weighing the choices about getting an O-A setup, it's been the one tool I wouldn't part with, versatile, intuitive in learning the process, and w/a small torch, you can make durn near anything. Sheetmetal welding come easily, w/the right settings and a little practice.
Ill chime in...im an AWS certified welder and a Navy certified welder...have done a lot of work with tons of different welding processes including CNC and robotic...every welding process has its advantages and disadvantages. O/A is great if your are experienced at using it...the key word is experienced...I know some welders that have been doing it 30 years that know how to do every kind of weld but when it comes to Oxy-fuel they cant do it to save their life...If you are looking to do any kind of sheetmetal work...good luck if you are in-experienced youre probably going to ruin the panel you are working on...Aluminum is a whole other story...you need special flux and colbalt blue lenses...I need to make it very clear you must use blue lenses with aluminum and only aluminum...Oxy-fuel is great for heating and cutting...un-beatable for that...But as for welding it is the softest weld...little penetration and if you are looking at doing anything with a ton of structural work turn away from Oxy-fuel welding...There is reasons why everything built pre-1940s was riveted together...the welding technology wasny there...heli-arc(tig) was developed pre-WWII for the aircraft industry and boiler industries...I know a lot about its development as my grandfather was a part of it...but it was really used throughout the war along with tons of SMAW(stick)...TIG has a smaller heat effected zone but you still have to watch it as much as Oxy-fuel you can ruin a panel just as easily with TIG...there is a lot of heat produced...but tig is the prefered method of welding for tube ch***is because it is the softest of electric welding processes...dont ley the scare you...it basically means if your in an accident there is more give in the welds to keep the ch***is together...TIG is also the best looking weld...but the key to good looking welds with TIG is keeping everything clean...the metal on both sides of the weld should be cleaned AT THE LEAST 1/2" from the weld...usually i do an 1" it should be cleaned to bright shiny metal...MIG is definated the cheapest and easiest type of welding...pretty self explainatory...but If it were me I would buy both an Oxy-fuel set up and a TIG set up...with those 2 things you could build anything you wanted from ch***is work tothe finest of sheetmetal work...you can even do brazing on br*** and copper with TIG & silicone bronze
OK guys, heres one for you.... I have a 120V Lincoln MIG. I'm OK at it, but I'm ALWAYS rusty and ALWAYS have to brush up before I do what I'm really set out to do (I'm a pencil pusher in real life, all the hard labor and dirty hands stuff I choose to do). I have an old-school OA rig, a pair of big*** bottles with Union Carbide regs (that you could drive nails with) and a Harris cutting torch (cutting only). I really would like to expand my welding abilities (and what I can weld), I'd like to take a cl*** but I don't think it's an option; I'd like to take a machine tool cl*** too, AND an auto body cl*** , but the "trade school" hear is really geared towards high school kids, not a 8-5 guy (they bus all the trade school students over to the trade school for half the day in high school), and at the community college you have to gain access to those things you have to be part of a full blown academic program. I have a good friend, actually my son's mom's uncle, who was as pure a hotrodder as they come, and made the most GOREGEOUS OA welds I've ever seen. Unfortuately, he's in advanced stages of Parkinsons and it's heartbreaking to try and watch him do work that used to come so easy to him. I would LOVE to pick it up, since it is so versatile (and because I'll probably never fork over the dough for a TIG box). Is this a skill that can be picked up by one's self (realisitically here, I'm an average guy with no "exceptional" abilities in these areas), or does it really need to be taught to you by an experienced user?
i'll chime in on this... my opinion might not mean any thing as a new member but here goes. i have been welding ever since my first shop cl***. the first rig i ever got was OA since it was cheap. i have since upgraded over the years but to better OA setups. no i use a dillon type torch. and weld just about every thing with OA including aluminum! there is a lot of skill involved with all of it. and years of practice. it took me about 3 yrs of screwing stuff up and learning from my mistakes. i have had instruction from masters (go hang out in the aircraft restoration crowd). but nothing will replace practice and lots of it. as for the strenght of the welds i will but my welds up with any other form of welding needed for auto's. right now my motor is suported by 10 OA tacks. but like i said and it is true of all welding. to be nice looking and strong... it takes practice. any one in the houston area who would like to learn hit me up. and come on by the shop. i'm not a master by any means but good at it. and i do believe it is a lost art. as it is not the popular method. and many will try to disprove it as such. and to all who see the videos for most of the "aircraft style" torches welding up coke cans and such. thoose guys are masters! it can be done it's not a trick but don't get pissed when your new fancy rig dosen't work like theirs! thats my $0.02
Beetlejuice, Good question! And I'm sure there's a lot of guys out there who are in a similar situation and would like to improve their welding (or other automotive) skills. You might try contacting your local welding equipment and supply store. They many times have 'seminars' put on by their various suppliers such as Lincoln, Miller, etc. that you could attend. Or, possibly your local supplier could reccomend a business or even a local individual that would be willing to have, or help, an 'apprentice'. JG
http://www.cut-like-plasma.com/ watch the videos well worth the investment in my opinion, just ordered mine last week, can't wait to get it here
i have yet to see a video of gas welding where you can actually see the puddle form and and watch as it moves along, every video shows a bright glow where the torch is heating the metal and thats it, no puddle shot, maybe someone has a link to a good video.
and to all who see the videos for most of the "aircraft style" torches welding up coke cans and such. thoose guys are masters! it can be done it's not a trick but don't get pissed when your new fancy rig dosen't work like theirs! cut-like-plasma is what i'm talking about. and i have that style torch. the henrob is just a dillon remake.
OA can be totally self taught but it's gonna end up so time consuming you'll seek out ***istance at some point. Grab some coat hangers and s**** metal and go to town. If you're making a molten pool the thickness of the metal you're mostly in business. Break your own welds with a BFH to verify you're penetrating and wetting the base material properly. There are a lot of non car projects that will boost your skills significantly. Do you need a metal fabrication table? A set of car dollies? Many times there's good reason to build what you can buy. Even though it costs more that's a cheap lesson. Good luck
Kent White is the man: http://tinmantech.com/html/alum_videos.php He shows you the puddle, and he has some great aluminum video's. On the one I have he blows a hole in the panel, and then shows you how to make a ball of aluminum using the flux, and drop it into the hole. He likes gas for panel welding, because it planishes better on a wheel or using a s****. Kent also sells gl***es for O/A. Gone are the Blue Cobalt days that blinded everyone. The TM-2000 lens works with aluminum and steel. The above info isn't necessary for steel welding, as that is pretty straight forward. Just practice, practice. He has some chrome-molly welding video's and I used those along with a cl*** from the Experimental Aircraft ***ociation. They put on a two-day workshop in Shawnee one year, and it was alot of fun. We built a lot of tubing type welds.
Please no. This is obsolete information. I've welded with both cobalt-blue and Kent Whites TM-2000 lens' , and his gl*** is much easier on the eye's and safer. http://tinmantech.chainreactionweb.com/html/tm2000.php His lens works with both aluminum and steel, and he also sells the little stick-on magifiers, which helps blind people (who used cobalt-blue) like me. Throw the cobalt stuff in the trash, or let your kid use it to make a stained gl*** window...
"Then cobalt melter's gl***es were borrowed from the steel foundries. When eye damage from these became prevalent (1980), they were quietly withdrawn from the market" hmmm, cobalt lenses can be bought at half the price and meet ANSI standards... http://www.fournierenterprises.com/cart/product.php?productid=16179&cat=&page=1 I find scotchbrite and a wipe with meths makes for a cleaner puddle.
I started using a OA rig because Tig and Mig where just starting to come out many years ago. They are fairly easy to use and you can see the puddle as you weld. As for ruining panels that is not true that is all we had and replaced many a quarter panel and none were ruined. If you are doing long welds on a large flimsy panel you just have to s***ch weld it in spots and move to another spot while the other one cools. Or use any of the heat blocking products out there to localize the heat and keep it from spreading. Unbeatable in bodyshop work as has already been pointed out you can also lead, cut off, stretch, shrink sheetmetal, and braze parts. The only word of caution besides the kids running around danger is picking up the hot rod from the floor by the HEATED end... you know thinking about what you are working on and just reach down and grab the rod.... you will quickly learn the old bodyman trick of putting a bend in the cold end so you know which is which and I wish my old apprentice master would have just told me about the trick BEFORE I learned the hard way by grabbing the hot end but you will never forget after doing it once.
I've tried (briefly) to gas weld panels with little to no success but I really didn't know what I was doing and I was using a cheap Harbor Freight torch setup(don't flame me!!!). I've become pretty good on my Lincoln 110 MIG and am ready to try a new method. I've been eying up one of those Henrobs that Eastwood sells. Maybe a Christmas present for myself...
I've done both gas and tig, the thing i would point out that wasn't mentioned is the amount of heat required for oa. Whengas welding everything around you absorbs the heat (tig focuses the heat on a pinpoint) and when everthing gets to temperature it'll act like a radiator. It's a bear to gas weld in august. One other thing is that you can't have a fan blowing for cooler air because it messes with the flame or blows away the argon (with tig). TIG is much cooler to weld with, i just use a sleeve with my tee shirt and have at it.
You have to read this stuff closely: "the Cobra lens eliminates the orange glare ***ociated with the use of flux" Sounds great doesn't it! "Exceeds the requirements of the ANSI spec for IR and UV protection for gas welding." Hmm, what does IR and UV have to do with Orange flare? Is there an ANSI spec for how much flare the eyes can handle per hour? Who knows. The answer is probably in some pathology medical journal. Using this logic, I could say that sungl***es exceed the ANSI spec for IR and UV protection.
NG and O2 is junk compared to O-A. Most that use NG use it cause its way cheaper and typically only on cutting torchs. I've used NG a fair bit, and you can get somewhat good with cutting with it, but using Actylene is spoiling its so much nicer.
How about the ability to hammer weld? That plus ability to shrink are sources of my interest in OA. How much does hammer welding help with the warping issues, as well as its benefits for finishing?
Hammer welding works great... localized right in the area you are working. Using a good technique you end up doing a lot less metal working to cure low and high spots and save valuable shop hours and finishing time. BUT the problem with warping using OA comes working with long panels like a quarter panel. You have to be careful for "plip plops" further away from the weld. Plip plops are the problem of long panels having a spot in a straight looking panel that if you push it from the outside it plops inward and if you push it from the inside it plops back into position. This is where OA comes in handy when you can heat the area then stretch it to "Tighten" it up to take the plip plop out then shrink the stretched point you just made back to normal with no plip plop. Can't do that with other welders. OA is great for bodywork and normal panels BUT other welders work better when working with thicker material no doubt about it.
For me, TIG hammer welds almost as easily as o-a. The o-a weld is slightly more malleable than TIG, but TIG is WWWWAAAAAYYYY more malleable than MIG. (I'm pretty sure MIG wire is a harder alloy than typical TIG/o-a filler rod, plus, I think there are some metallurgical issues that make MIG welds rock-hard, but brittle.) As others have mentioned, TIG has a smaller, more focused heat-affected zone (HAZ). It's nice because there's an instant puddle, so you can get in there and back out nearly as quickly as MIG. claymore refers to the "plip-plops" (I've always heard it called, "oil-canning", but either term works.), which can really freak you out when they appear. This usually indicates an area that needs to be shrunk, as it has expanded too much, and it's pushing outward on the metal around it. I'm still having trouble getting the hang of torch-shrinking, but once you learn this skill, you can really correct some nasty stuff.
Slide I started another thread about shrinking with OA so we don't spam up this members thread see it at: http://www.jalopyjournal.com/forum/showthread.php?p=3895698#post3895698
My welding supplier carries the heat absorbing putty. In the old days the stuff contained asbestos and after using it you could mix it with a little motor oil and water and put it in the can to reuse later. the new stuff has NO asbestos. you roll a bead like kids modeling clay and put it about 3/4 inch from the weld area and press it down on the metal. after welding i clean it off with a putty knife and put in another can. I haven't tried to remix with water to see if it can be reused like in the old days.
The orange flare is eliminated and the claim blue lenses quietly disappeared from the market in the 80s is BS and brings the rest into question with nothing to back it up. I'd have a hard job convincing my employer we have a problem with such scant information.
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