ChrisBradley04
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| posted on 23/5/04 at 10:28 PM |
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Aluminium welding
Hi,
I am looking to learn to weld aluminium. Can anyone point me in the right direction to start please?
I almost bought a TIG welder set only to discover that you need AC and not DC to weld aluminium. I had the cash in hand so almost a very expensive
mistake
Any advice at this stage would be really appreciated.
Regards
Chris
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stephen_gusterson
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| posted on 23/5/04 at 11:11 PM |
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Im told that welding alu needs a lot more skill than steel.
if you only need to do a little welding, look up something called technoweld.
Its fluxless, done with a blowtorch, a lot like solder. Its worked for me welding small internal corners.
'real' welding can be advised by mark allanson or viper
atb
steve
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Hugh Paterson
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| posted on 23/5/04 at 11:27 PM |
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A good AC/DC TIG welder is worth its weight in gold, but prob not worth the expense if you are only going to weld ali now and then. There are also
good MIG machines that do ali, but you dont want to consider one of them unless u want to go into business on a regualr basis producing lots of ali
fabrications.
If your determined to try welding ali with Tig suggest u take a course in it, before u part with your cash Im still saving
mine for the machine of my dreams
cheers
Shug.
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flak monkey
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| posted on 24/5/04 at 08:31 AM |
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I had a go at TIG welding ali a few weeks back. With a good tutor i managed to get a technique going in about 2 hours. After that its just practice,
which i didnt have time to do.
I did learn several useful tips though....
When TIG welding ali, due to the rapid heat loss, the welds have a tendency to crack due to very rapid cooling, in tubular structures especially. So
you maye have to preheat and post heat what ever you are welding....all a lot of hassle. This becomes even more of a problem if there is even a slight
draft...
And yes you do need AC as it 'lifts' the oxide from the ali.
Another thing to bear in mind ali welding is a lot brighter than you could ever imagine, its also bright white light, much brighter than MIG welding
steel. You really do need a darker helmet for ali, DIN14 or more.
Just a few things i picked up/was told,
Cheers
David 
Sera
http://www.motosera.com
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MikeP
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| posted on 24/5/04 at 01:08 PM |
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What are you looking to weld Chris? If you're thinking about ali sheet, you could consider gas welding if you've got a torch already.
I've got the begginer kit from http://www.tinmantech.com/. It's trickier than steel, but watching his video after a few hours practice I
was starting to run some good beads.
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ChrisBradley04
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| posted on 24/5/04 at 06:31 PM |
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Thanks guys. It sounds like there is a lot more to it than I had hoped (and a lot more expensive)
I don't have anything in mind to make, but had noticed when I built my last car it would of been really useful to have been able to make ali
brackets etc.
I think I will just learn to MIG weld and use steel
Thanks again.
Regards
Chris
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RPS
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| posted on 28/5/04 at 07:17 AM |
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Anyone know if you can gas weld with Aluminium with a propane set, or do you need to have Acetylene?
Cheers.
RPS
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Mark Allanson
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| posted on 28/5/04 at 08:27 PM |
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Gas welding ally is a very VERY special skill, TIG welding is not too difficult, everyone seems to ignore MIG welding the stuff, all you need is a
teflon liner, pure argon, ally wire and a couple of hours practice
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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MikeP
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| posted on 29/5/04 at 01:04 PM |
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Welding ali needs O/A or O/H, it can't be done with propane, though I think you can use propane for the weld the technoweld (never tried it).
The Tin Man suggests that for bodywork it has to be TIG or gas - MIG leaves the weld too brittle to work. I'm not sure about technoweld.
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Browser
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| posted on 29/5/04 at 04:42 PM |
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Technoweld is OK but since you need to heat up the whole workpiece it can take a LOT of heat (Oxy Ac needed most times). Also, you can get one bit
looking good, move on to the next bit & re-melt the first so if you have a large area or lots of different little bits you may have to use MIG.
I've used MIG and, as long as you don't expect TIG-like results it's pretty good. You need the wire feed & current quite high
(well, you do on my Snap-On 130 turbo anyway) but a little practice will see you right. Feels kinda cool being able to join Ali, dunno why
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flak monkey
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| posted on 29/5/04 at 05:25 PM |
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TIG welding is great. (Produces a hell of a lot of distortion on thin steel though!)
After about an hours tuition and 20mins practice at TIGing I managed to be able to do Ali welds that look like this....
Just need to practice more now!
 
Rescued attachment ali weld 2.jpg
Sera
http://www.motosera.com
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madforfishing
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| posted on 2/6/04 at 08:56 AM |
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You can't weld CAD models ! 
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JoelP
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| posted on 2/6/04 at 09:03 AM |
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i might end up welding ally soon if i get this damaged mast im thinking of getting... project 2.
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flak monkey
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| posted on 2/6/04 at 10:38 AM |
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quote:
You can't weld CAD models !
I tried...but it didnt do my PC much good...
Sera
http://www.motosera.com
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Jim999
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| posted on 4/6/04 at 03:02 PM |
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Alu Welding
Some tips that come in handy from a certified welder.
1) ALU welding is Expensive and time consuming to get a good TIG AC welding set with gas tourch and all the kit your talking well above £1000 this
expenditure will allow you to weld most aluminuim up to 6mm thick.
2) Welding Alu is hard but not as hard as copper. The problem is ally is a great heat conductor once it starts to melt it melts fast. Not only this
but it instantly oxerdises upon contact with air. This means when welding you need pure argon gas which again is £££ and you need a lot of it if your
think about a chassis.
3)Is thier really any avantage from manfacturing a chassis from ally. first it will be a lot weaker a secoundly its gonna cost more in time and
money.
4) You will probably find that if you do some CAD/FEA work inside a package like ansys (stress analysis tool) the weight you save is maginal by the
time you've strengthed the frame enough not to effect the suspension performance.
5) So you've done all the design work what next. Learn to weld of course ah well the welding was diffcult but hold on whats all this buisness
that the guy teaching me is doing with the equipment setup. Exactly TIG AC welding is reliant on serveral things unlike welding normal steel were your
mainly concerned about the amps ac welding is very diffcult to set up even more so then the actuall welding itself. This is because it relises upon
not only amps but the volts frequency and the gas flow rate just to name a few. Oh and making the items clean enough and by this i mean labortory
clean if you want really good welds.
6) Is thier a way round this the aswer is you can either buy a welder that is £6000 that allows easyier setup or go on a certified course and learn
about the theory and get a proper welding certificate. Which is the course i took back in 1993.
7) So end result i have got a chassis that maybe 20kg lighter and still as stiff then a steel chassis but was it worth it ? When you consider carbon
fiber and other methods like aluminuim honey comb my answer probably no certainly if your working in racing.
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