Gas wielding

[IronicCapers]

Heard a lil rumour and i mean my tutors an idiot who according to other more professional older tutors he cant weild but he this twat said that you can gas weild aluminum.

Now if thats possible what flame setting would i need because i know its a non-ferrous metal that reacts to oxygen. And of course aluminum has an outer casing of naturally forming oxygen. And aluminum is one of the most reactive metals.

Any views on this as i wanna cut down on taking my sub frame to the boat builders(thanks blade runner an Tjebbe an dave).

[Ixion]

Yes, you can weld aluminium with oxy acetylene.

It's not easy though, and now that TIG is around not many people would.

You need to preheat castings. Use a neutral or slightly reducing flame, start out large and soft and heat the area of the joint, then cut the flame size down .

You MUST use the right flux. Talk to the rod people, there are special rods that make it easier.Melt both edges of the joint, then melt a bit of rod into the molten pool in the joint - move the ord inot the pool then withdraw it. And move along, forward hand.

Practice, practice, practice.And , do remember, aluminium is hot short.

You can also get zinc based rods that are easy to use as a sort of "aluminium brazing", but this is not as strong as welding.

However I would NOT recommend anyone use oxy welding on an aluminium motorcycle frame. The risk of failure due to a bad weld is too great.

[oldguy]

Yes you can gas weld alum, did it years ago when I was an apprentice sheety, can't remeber the flame settings, my uncle has this gas set I remeber I guy giving a demo of what this gas set could do and he welded a coke can no problem

[rfc85]

Yes, you can weld aluminium with oxy acetylene.

It's not easy though, and now that TIG is around not many people would.

You need to preheat castings. Use a neutral or slightly reducing flame, start out large and soft and heat the area of the joint, then cut the flame size down .

You MUST use the right flux. Talk to the rod people, there are special rods that make it easier.Melt both edges of the joint, then melt a bit of rod into the molten pool in the joint - move the ord inot the pool then withdraw it. And move along, forward hand.

Practice, practice, practice.And , do remember, aluminium is hot short.

You can also get zinc based rods that are easy to use as a sort of "aluminium brazing", but this is not as strong as welding.

However I would NOT recommend anyone use oxy welding on an aluminium motorcycle frame. The risk of failure due to a bad weld is too great.
heah heah its a damn hard job to gas weld alli, use tig or mig but again its not an easy job,may pay to get it done properly

[Motu]

Yeah,tricky stuff alright,you need a lot of practice - then it's pretty easy.But I've never got to that point.One thing is you need far more heat than you think,it transfers heat fast and you got to keep feeding the heat in...and then it doesn't melt like steel,it goes plastic...and then plop...it's on the floor.You'll need a lot of practice before you attempt your subframe.

[merv]

I did it back in the '70's and one of the key issues is it doesn't really change colour, you have to watch the liquidity i.e. it doesn't go red hot and as said above heat it too much and next thing you know its all over the floor.

[Vagabond]

From my experience, if you burn the aluminium black with the acetylene (no oxygen) then when you start heating the ally up,you will have a guage to know when the temp is just about right, which will be when the blackness disappears. Remember you will only have seconds before it's all on the floor!

[IronicCapers]

Oh yep soundsd bloodly hard alrite. Well thats one more myth cleared up. Since it has the strange reactions of being incredibly plastic rite i think it mite jus be the idea to simply buy a TIG or jus take it down to the people who know best.

Although il will keep the info and start practicing cause you never know wen you mite need it.

[Ixion]

Unfortunately, the cheaper TIG units won't cut it for ali welding. You need the more expensive DC ones. Sigh. I'd like one, but I just can' tjustfy it.

[Motu]

Or the Dillon or Henrob torch,they will weld (wield??) alloy with no prep or preheating.I've got one,and they certainly do it better than a standard gas torch....but alloy welding is still 90% opperator skill,and I'm at 20% level.Get hold of Death,he's the man for alloy welding.

[Sensei]

Gas welding is easy as shit . you set the torch up with a black carbonising flame & wipe across the ally so as to black it then set back to a Netrual to slight oxidesing flame & heat the ally till the point when the black carbon starts to burn off then the plate etc is ready to weld use a dipping method as with S/S & carbon gas welding . Start practicing with thin metal as it will heat quicker & is easy to get the pool flowing . As with all things after 30ys of doing it it is just like breathing air . Be patent .

[DEATH_INC.]

Get hold of Death,he's the man for alloy welding.
Never really tried to gas weld it though (I use tig)......may hafta give it a shot....

[sAsLEX]

1 part aluminum 1 part ferrous oxide(rust)

ignite with a hot flame, using a piece of magnesium, and :gob: thermite!

[RiderInBlack]

Know some of the top competition Farriers (horse shoers, I know not bikes, but it's me job, OK) gas forge weld Alloy ta make Alloy Egg-Bar horse shoes (completely round horse shoe without an open heel). Bloody hard cause it is so easy ta end-up with a pool of alloy in the bottom of ya forge. A good one and ya can not even see where they have welded it. Must ask them what they use for flux. I'd be worried about getting the right tempering done after ya finished if it was for part of a bike frame. It's easy for Alloy to loose it "temper" and therefore it's strength due to heat. Fire damage fu*ks Alloy scuba diving tanks real quick, making them too dangerous to fill.

[Motu]

Hammer weld alloy? Supposed to be the strongest joint,I don't know about these days,but it was once the only way you were allowd to join ships anchor chain.

[clint640]

I'd be worried about getting the right tempering done after ya finished if it was for part of a bike frame. It's easy for Alloy to loose it "temper" and therefore it's strength due to heat. Fire damage fu*ks Alloy scuba diving tanks real quick, making them too dangerous to fill.[/COLOR]

Thassa good point. T6 heat treatment is pretty easy to do if you have access to a big enough hot enough oven though, do a search, it's something like 600deg for a while then 200deg for a bit longer. I've done it to a few MTB bits after they've been welded with no probs. You do need to know the alloy but it's most likely 6061.

Cheers
Clint