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I've trawled through the internet for info and now I'm after some knowledge from experienced folk.
Gas welding 1000 and 3000 series alloys to make cowling pieces for a FRED, which has no plans for firewall-forwards and thus has to be home designed and fabricated. The original one I made in GRP is a bit flat at the front so I rolled a new nose piece that I'd like to add a rear section to in order to make a complete new upper section in lighter alloy.
Will oxy-propane work instead of oxy-acetylene? What torch/bottles/suppliers do you recommend? Where from?
I've done plenty of MIG welding of steel before but no welding with gas or welding of alloys. I know I could rivet it together but it somewhat defeats the object of 'homebuilding' for me since I wouldn't be learning anything new.
there was a bit of interest on the Flitzer forum recently regarding brazing of aluminium as an alternative to welding, it did look a useful and potentially easier solution for the novice. The products Durafix and Lumiweld come to mind as filler rods.
Rob,
you can weld aluminium with a torch of course, but it's preferable to weld using an oxy-hydrogen mix rather than acetylene. The reason is simply that it produces a cooler flame and that equates with the lower melting point of aluminium. Buy some ally weldig rods and the correct flux and have a go! Be prepared to be frustrated while you learn to recognise flame colour and weld pool colour etc, and pre-heat the filler rod because the weld pool will be cooler and sticking a cold ally filler rod in there will just cool it down too much.
It's a long time since I tried it, I sold my oxy-gear years ago but often regret it! There's always TIG of course and that's a very similar technique to gas welding.
Nigel. Do you know if you can ali weld with oxy-propane mix since that is one mix that I can get without having to pay an anual rent on the bottles.
I assume that TIG welded pieces will still be able to be planished down or rolled through the english wheel easily, unlike MIG?
I'd prefer to get a suitable gas welding kit than TIG because of the OTT cost of a decent TIG kit for so few jobs.
Anyone got some suitable ali gas welding kit for sale, or even a decent TIG?
Hi Rob and a Happy New Year! Bernzomatic do a yellow cannister of gas which I think is an acetylene substitute possible called MEK which can be used with their oxygen to give more heat if required.
John.
Rob,
I don't know the answer regarding propane, but it may be 'dirtier'? With regard to a previous post, you don't need more heat than oxy/acetylene hence the oxy/hydrogen mix.
As for wheeling the weld, even a tigged piece would be achieved with aluminium filler so it would be soft enough (I had a guy do some ally welding for me on-site using a portable inverter. He and I then wheeled the piece (6' long!) successfully).
I don't NEED a TIG outfit, but it's one of those things that would be excellent to have in the workshop both for steel and ally. Ally TIG welding requires an ac inverter and thus is much more expensive. It's all down to balancing the need versus the want quotient!
A gas set is really useful around the workshop and a set of the little bottles (not canisters) isn't so expensive. People have welded aluminium with oxy-acetylene, it just takes a lot of practice.
I only have MiG set at the moment, but a small oxy set would be great for everything from freeing off recalcitrant car bits to brazing etc. Oh no, I feel an Ebay foray coming on!
I went to see "Mr Aluminium" in the metal shop and he gave me some 1050 to try. It ought to (according to him) be suitable in 1/2 hard spec for wheeling to give a polished finish (unlike the piece of 1000-series above) and it welds AND brazes nicely. Now, how do you BRAZE ali????
I've found a good site for tips on al welding with oxy and a good torch for the job. http://www.cut-like-plasma.com/
Nice videos on their site. Might be a contender?
One source of FREE very high quality aluminium sheeting for non structural work is from a lithographic printer. They are about the size of one of the large newspaper pages, and I got about fifty from a printer in Dingwall.
If I can just make a comment here, why go to the expense and trouble of buying new kit and learning the method when there are approved welders who could do the jib for you so quickly and cheaply it isnt worth the effort. Fair enough if you are going to do loads of Ali welding but justt for one set of cowlings???
No doubt I will get shot down over this but I would rather get my welding done by someone qualified. My welder is ex Rolls Royce and does a fantastic job.
