O/A welding aluminum help

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what kind of setup do i need to weld aluminum?im buying a "set" come with the tanks that are bigger than the portable.what will i need thanks
Reply:You want to use O/A to weld Al? That is a whole different skill to master, you may want to start saving money a get a AC/DC tig machine.  If your trying to find a cheap way to weld Al  by going O/A I think it would be better to take a class it would give you an idea of what to expect without spending alot of money.
Reply:Hello,        You will need to use a slightly carburising flame for ally. Have not done much but as usual, practice on scrap first, Good luck.Lincoln SP-170 MigHypertherm powermax 45Lorch T220 AC/DC TigButters FM 215 synergic MigKemppi 180 adaptive mig RULES ARE FOR THE OBEDIENCE OF FOOLS AND THE  GUIDANCE OF WISE MEN.
Reply:http://www.tinmantech.com/ is one resource/vendor you should get acquainted with for O/A welding aluminum.I had some success with it, but no where near as good as I am getting with my new TIG setup.  (IME, the TIG allows better heat control, and avoids the aluminum welding flux problems.)   But here is what I can say about it...It definitely is possible to do.you need the metal to be prepared absolutely pristine clean.  You need to remove the "invisible" oxides on the weld joint before welding.  I had best luck doing this mechanically, with a scotch-brite like pad, or plastic abraisive impregnated wheel or cup brush.You will need to flux the surfaces to be welded, and/or your filler rod.  You should plan on removing the flux after welding.  The flux contains acids which will BADLY corrode the aluminum if you just leave it on there.  You will need access to the back sides of your weld joints to be able to mechanically brush away the flux.  IMO, flux removal is a big problem for some weld joints, but not much of a problem for others.  I hear you can alternatively remove the flux with nitric acid, but post 9/11 (it is a primary ingredient for making things that go "boom"), good luck getting a hold of that.  And it sounds like horribly nasty stuff too.If you mess up and oxidize the joint, you will need to mechanically remove all the oxides (including those trapped in a weld joint that didn't get proper fusion) and that might mean grinding away a portion of the work and needing to patch it, and start over.  If you do it right though, you can get very good results on the first try.Oh yeah, preheat heavy parts (IE: castings) in an oven to 400 degrees before welding.  Otherwise you will be sitting waiting there forever to try and get a puddle to form...Wait for the shiny puddle to appear before attempting to dip fillier rod into it.  Don't let your filler rod melt before dipping it in the puddle.  Be very careful watching the torch angle, distance, and tip and flame size (to control the heat) or you will melt away parts you wished you didn't melt away very quickly!Edit: by the way there also exist some (maybe only relatively large diameter) aluminum filler rods that have flux core inside them, I've got some of it.  However I still liked using some flux painted on the joint directly, so so it wouldn't oxidize when I am heating it up to welding temperature.Last edited by jakeru; 06-27-2010 at 04:27 PM.
Reply:Oh by the way, you might also want to consider using an aluminum brazing material to join aluminum with an oxy-acetylene wetup.  The aluminum braze rod contains aluminum and zinc, which lowers it melting point.  That stuff is pretty easy to work with, doesn't need flux and don't really need to worry so much about oxidation problems either.  However, you can't really "build it up" like you can welding a real aluminum alloy, because all the previously added braze will rapidly liquify and fall away from where you put it if you go to re-heat it to try and add more.It is nasty (but possible) to TIG weld it afterwards.  The zinc in the aluminum braze will burn and pop and make kind of a mess if you TIG it too hot.  With practice, maybe possible to do it without burning it, but that's what happened IME.  It will melt away a little bit next to the TIG weld, but because TIG heat is so concentrated will mostly remain in tact.Best braze joints are tight fitting, with a large surface area.  Unlike a weld joint in that aspect.  The zinc braze is also plenty strong (likely stronger than the aluminum alloy) as long as it stays cool.  Some "real" aluminum alloys (7000 series I think?) have zinc as the primary alloying ingredient.  Can be very strong.
Reply:Ok, to clear up some things here, and provide insight from a guy that actually does this mystery welding quite often, here ya go:1) Cleaner surfaces give you an easier time welding, however arent as critical as for the Tig process. Meaning the cleaning process is the same, but the torch will do parts the tig cant ( i.e. oil soaked castings  and oil coolers )2)The corrosive agent of the flux is the salts, not acid, just like any salt on aluminum, and its treated the same. Comes off easily with hot water and a nylon scrub brush, or boil the part, or any number of water based cleaning methods. Trapped salts are fine, so lap joints must be welded on all sides. Its more of an issue for production, not the hobbyist.3)Casting pre-heat same as tig, no biggie4) Proper aluminum brazing material is an aluminum/silicon alloy, not aluminum/zinc. The zinc alloys have good strength, but poor ductility and can embrittle the base metal. Plus is is nearly impossible to re-do a repair over the zinc, and the entire section needs to be cut out. Real brazing material is typically 4047 filler, used with a flux such as Esab Allstate 53 or the brazing flux from www.tinmantech.com.5) There is no flux core welding rod.....period.....never was really.... All the literature available shows that all of the flux core alloys have been 4047, so they are brazing filler. There was a flux core rod of 1100 alloys made in the 1930's however the natrual corrosion between the welding flux ( welding and brazing fluxes are different, and there are corrosive and non corrosive versions of brazing flux ) and filler turned them useless within a short time, so the idea was dropped.6) On the subject of brazing fluxes, the non corrosive types are useless on 5xxx series alloys, and not much good on the 6xxx series. Corrosive types are used here.7) Buy the right lens, the TM2000 by far is the best, and its a piece you will appreciate no matter what your welding, steel, aluminum, cast iron, bronze, copper, lead, magnesium, you name it. The short of it is that aluminum torch welding is getting VERY popular again for people that work in the thickness used in aircraft construction and the like. Any class taught on it is filled within days, and huge companies like Esab, still turn out tens of thousands of pounds of flux a year. It has its real engineering advantages over Tig, hard to swallow but true. So anyway, my suggestion would be to hook up with someone at the local airport that welds with the process, and learn. We teach it as much as we can every year at the EAA convention, and I wish we had more time than we do as its always a crowd.-Aaron
Reply:Originally Posted by makoman1860Ok, to clear up some things here, and provide insight from a guy that actually does this mystery welding quite often, here ya go:
Reply:Mako,jakeru,So which process would you recommend to someone starting out?  The OP is looking the work on a 1000 cc gokart and is just starting to learn to weld Al. With all  the various accesories that would be need to go with O/A welding is it really that much cheaper then tig?
Reply:Originally Posted by Jay OMako,jakeru,So which process would you recommend to someone starting out?  The OP is looking the work on a 1000 cc gokart and is just starting to learn to weld Al. With all  the various accesories that would be need to go with O/A welding is it really that much cheaper then tig?
Reply:http://www.harrisproductsgroup.com/c...lloys.asp?id=2I think cor-al   is for brazing.
Reply:Originally Posted by jakeruThanks for adding to the discussion, Aaron.  But, I do wonder if you actually have experience TIG welding aluminum?  If not, I would suggest not to draw comparisons you've heard "someone else" make between the two processes, as it may be repeating possibly misleading or inaccurate information..
Reply:Originally Posted by tapwelderhttp://www.harrisproductsgroup.com/c...lloys.asp?id=2I think cor-al   is for brazing.
Reply:Originally Posted by makoman1860Solar flux is for nickel/FE alloys, not aluminum.
Reply:Originally Posted by jakeruSolar Flux "B" is I believe what you are thinking of, for stainless/nickel/iron.  Solar Flux "OA" I think they called it, (but memory is a bit foggy and I don't currently have any in my posession,) was their aluminum welding flux product.  I don't believe they make or sell it anymore, it now seems to be discontinued.And while I appreciate a lot of the O/A technique you bring to the discussion, I've got to ask what the heck is wrong with welding a part, that may happen to be a casting maybe not, without pre-heating it?  I'm guessing your objection has to do with reducing distortion.  But seriously, if its a heat treatable aluminum, it may be advantageous for strength actually to *not* pre-heat it.  (Not to mention, to use the focused heat of the TIG arc rather than non-focused oxy fuel flame.)Skipping the pre-heat can certainly simplify the process and save time, by skipping unnecessary work.  Doesn't it come down to what is the thickness / heat-sink mass of the metals you are joining compared to what is the heat transfer capabilities of the welding equipment you are using?  TIG allows much more concentrated heat than O/A welding, if you hold a very tight arc, that was my point, and it doesn't sound like we're debating that.
Reply:Originally Posted by moneymaker17basily what rod/flux is the best for me for welding aluminum on my go cart. i think im going to my welding shop tommorow to pick up some stuff
Reply:ok making the 3 mules welding suply trip list.1. fill both bottles2. cutting tips3. welding tips4. welding rods.5.welding mask6. couple strikers7. tip cleaneranything else i should get?
Reply:Originally Posted by moneymaker17ok making the 3 mules welding suply trip list.1. fill both bottles2. cutting tips3. welding tips4. welding rods.5.welding mask6. couple strikers7. tip cleaneranything else i should get?
Reply:ok so i got my tanks filled got acouple things. put everything together and when i got it all together i tryed it.turned the acy on first? strike it. flame... turn oxygen on then when i hit the lever it goes out? whats wrong? help lol thanks guys
Reply:Ok number one, from what you describe, you are planning to cut not weld right? The cutting head has the lever, a welding tip does not. Trying to weld with the cutting head can be done, but it's much harder.To cut: 1st set the acet reg to 3-4psi, Oxy to 20-30psi. See if when you open up the valves on the handle the settings change greatly. You may have to adjust the pressures a bit if so.2nd turn on the acet and light it. Add acet till the flame starts to want to jump off the tip and the black soot goes away. Then add O2. Depending on your torch you will have 1 or 2 knobs for O2. If 1 no problem adjust away. If 2 knobs, the one on the torch handle gets opened all the way up, the knob on the cutting handle adjusts the preheat O2. You want to add O2 till you have a clean inner cone and the feather is gone from the outter cone. (makes more sense if I could show you this).3rd when you squeese the handle you should hear a woosh but not see a dramatic change in the flame.4th start heating an edge. wait till it starts to melt a bit and squeese the handle. It should start to cut and throw sparks. When it starts cutting, move. If you move too slow the slag will fill back in behind you, if you move too fast you will loose the cut.If you want to weld/braze 1st you should get the right tip for the job you plan to do. Each manufacture has a chart that will tell you what size tip is for what size material along with reg setting ranges for each tip..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thanks awhole lot!!!!! got it going and started cutting!!!!!!!!on the acly bottle the nozzle like what you open and close the gas with didnt come with it. where can i get one? welding store. forgot! im going to order a bunch of stuff online any ideas?
Reply:There's a tiny wrench with a square hole in it for those "B" tanks. I found that the knob from a scuba cylinder fits that almost perfect. Thats what I use on my "B" cyl for the air/acet torch for soldering.  I find it harder to loose than the wrench and easier to turn on and off. I've seen plumbers with vise grips on there to turn them on or even small open end wrenches. Attached Images.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thats what i used today. but id rather have the knobs.
Reply:If you want the knobs, I'd suggest going to a scuba shop and seeing if they have any dead valves and would be willing to sell the knobs. Some shops will sell the knobs new, but will have to order them. If you can't find any at a local shop, let me know and I'll see if I can scrounge up one at a friends shop or get them to order one..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thanks!
Reply:i also took an old i mean old (me and my buddy actually found it burred in the dirt when we were scraping metal for this guy month ago) anyways when i drove my jeep around back to exchange the tanks i said will you guys take this. he said yes! i said OK! ill go pay for it right now.and i mean this thing was rusted beat up looking! lol Great Deal!it was the small 20cf in the picture  Attached Images
Reply:Some of the aluminum, brazing rod is hard you cannot file it easily.        Sincerely,             William McCormick
Reply:To give you an idea of what oxy-acetylene aluminum braizing looks like...This is part of an engine intake manifold piece that I braized (before eventually machining), shown right after braizing, without any wire brushing or anything done to it.  Notice how nice and shiny the braize material is, how it's completely flowed out between the two pieces (one having a rather complicated shape, the other flat so the braize material pools nicely on top of it.  Also notice the complete absense of flux. William is right by the way, the zinc-aluminum braizing material is noticeably harder than aluminum when you take a file to it. Attached Images
Reply:Originally Posted by jakeruTo give you an idea of what oxy-acetylene aluminum braizing looks like...This is part of an engine intake manifold piece that I braized (before eventually machining), shown right after braizing, without any wire brushing or anything done to it.  Notice how nice and shiny the braize material is, how it's completely flowed out between the two pieces (one having a rather complicated shape, the other flat so the braize material pools nicely on top of it.  Also notice the complete absense of flux. William is right by the way, the zinc-aluminum braizing material is noticeably harder than aluminum when you take a file to it.
Reply:Originally Posted by moneymaker17what kind should i use? im welding onto a sae forumla f1 car
Reply:Originally Posted by moneymaker17what kind should i use? im welding onto a sae forumla f1 car
Reply:Originally Posted by jakeruTo give you an idea of what oxy-acetylene aluminum braizing looks like...This is part of an engine intake manifold piece that I braized (before eventually machining), shown right after braizing, without any wire brushing or anything done to it.  Notice how nice and shiny the braize material is, how it's completely flowed out between the two pieces (one having a rather complicated shape, the other flat so the braize material pools nicely on top of it.  Also notice the complete absense of flux. William is right by the way, the zinc-aluminum braizing material is noticeably harder than aluminum when you take a file to it.
Reply:Here is an example of a restricted access fillet joint that (IME...) OA did not have enough heat control to successfully weld.  There was too high a risk of melting the machined edges, which I needed to keep "solid".  Second pic shows that fillet successfully welded with TIG.  For extra credit, see if you can find other defects in the first pic that are no longer present in the second pic.With TIG, I managed (with ease!) to stick the tungsten deep down into this groove, and concentrate the heat right in the deepest part of the fillet groove, where it was needed.  An OA flame I believe, would have likely spread the heat out too broadly, and I believe would have likely melted the machined edges, even with pre-heat.  This is an aluminum casting, about 1/4" thick.  This was successfully welded with an inverter TIG machine using mostly not more than 180 amps and an air cooled torch.  In many cases without any pre-heat (although a little bit of quick pre-heating using just a cheap, "bernzomatic" air-propane torch and a disposable propane bottle did work nicely, for those areas I was concerned about distortion control.) Attached Images
Reply:Originally Posted by makoman1860Ok, to clear up some things here, and provide insight from a guy that actually does this mystery welding quite often, here ya go:1) Cleaner surfaces give you an easier time welding, however arent as critical as for the Tig process. Meaning the cleaning process is the same, but the torch will do parts the tig cant ( i.e. oil soaked castings  and oil coolers )2)The corrosive agent of the flux is the salts, not acid, just like any salt on aluminum, and its treated the same. Comes off easily with hot water and a nylon scrub brush, or boil the part, or any number of water based cleaning methods. Trapped salts are fine, so lap joints must be welded on all sides. Its more of an issue for production, not the hobbyist.3)Casting pre-heat same as tig, no biggie4) Proper aluminum brazing material is an aluminum/silicon alloy, not aluminum/zinc. The zinc alloys have good strength, but poor ductility and can embrittle the base metal. Plus is is nearly impossible to re-do a repair over the zinc, and the entire section needs to be cut out. Real brazing material is typically 4047 filler, used with a flux such as Esab Allstate 53 or the brazing flux from www.tinmantech.com.5) There is no flux core welding rod.....period.....never was really.... All the literature available shows that all of the flux core alloys have been 4047, so they are brazing filler. There was a flux core rod of 1100 alloys made in the 1930's however the natrual corrosion between the welding flux ( welding and brazing fluxes are different, and there are corrosive and non corrosive versions of brazing flux ) and filler turned them useless within a short time, so the idea was dropped.6) On the subject of brazing fluxes, the non corrosive types are useless on 5xxx series alloys, and not much good on the 6xxx series. Corrosive types are used here.7) Buy the right lens, the TM2000 by far is the best, and its a piece you will appreciate no matter what your welding, steel, aluminum, cast iron, bronze, copper, lead, magnesium, you name it. The short of it is that aluminum torch welding is getting VERY popular again for people that work in the thickness used in aircraft construction and the like. Any class taught on it is filled within days, and huge companies like Esab, still turn out tens of thousands of pounds of flux a year. It has its real engineering advantages over Tig, hard to swallow but true. So anyway, my suggestion would be to hook up with someone at the local airport that welds with the process, and learn. We teach it as much as we can every year at the EAA convention, and I wish we had more time than we do as its always a crowd.-Aaron