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Welding aluminium ?
Wingnut - 5/7/04 at 11:59 AM

Has anyone tried wleding aluminium using a MIG welder with the appropriate wire??

My welding stockists said it's a no-no, unless I use different gas, wire feed etc...

Anyone tried it with a regualr mig & Argosheild??


Staple balls - 5/7/04 at 12:05 PM

as i understand it. it's a no-no unless you're very skilled, using the right kit, and can get the work heat treated after


white130d - 5/7/04 at 12:06 PM

I weld aluminum with my Millermatic 200 with a spoolgun and straight argon. The problem with most Migs is trying to push the very soft ali wire through the hose/gun, with the spool gun it only travels 6" straight so it doesn't bind up.

David


MikeP - 5/7/04 at 03:34 PM

I tried it with my push type low end MIG. The ali would bind up just after the pinch roller and make a mess, I got frustrated so I never got far enough to find if there was a feed & power setting that would work.


NS Dev - 5/7/04 at 05:06 PM

I've done it with a Clarke 150 TE "low end" welder and straight argon and went okish.......the welds were crap though!! The problem was the lack of heat control with the MIG, in order to start the pool you need loads of very localised heat, otherwise the ally just conducts it away, heating the whole piece up to melting point at the same time. This is why AC Tig's tend to have variable amp foot controls. Boost the amps up to start the weld, then back off to continue it, and back off again at the end of the seam. The Tig is a far more concentrated and focussed heat zone too so minimisinf conduction away from the weld area.


Viper - 5/7/04 at 05:06 PM

You will need pure argon, a teflon liner, and lots of practice till you find a set up that works, even then the weld will look shite,
Tim


DavidM - 5/7/04 at 11:17 PM

You also need to brush the joint vigourously with a stainless steel wire brush before welding to temporarily remove the oxide film from the surface of the aluminium. This film has a higher melting point than the aluminium itself and removing it will allow the use of more controllable settings, resulting in a more satisfactory result.

[Edited on 5/7/04 by DavidM]


Mark Allanson - 6/7/04 at 06:49 PM

Try it with sexy ahotalene, my efforts were passable but not brilliant - VERY difficult


spunky - 6/7/04 at 08:37 PM

If you think MIG welding ali is tricky, you should try arc welding the stuff. Thats what I had to do at work 'till I convinced them to buy a TIG....

John


albertz - 7/7/04 at 12:27 PM

I was just about to post this very question, then i noticed this link.

I am considering trying this technique to modify the inlet plenum on my engine. From the responses above, it seems that it is just about possible but looks crap.

In my limited experience, of welding in general, i have found that welds that look crap actually are crap and sometimes welds that look OK are still crap.

What i really need to know is about the weld strength. I dont think that i need incredible weld strength for this particular part, mainly it needs to be airtight and just strong enough to hold its own weight etc.

Do you think this is a reasonable item to attempt this ali welding on?


Mark Allanson - 7/7/04 at 04:13 PM

Try you skills and equipment out on some scrap first!


MikeP - 7/7/04 at 04:52 PM

MIG welding on something like the 4AGE intake plenum Albert? The guys here should be able to help, my first thought is that it's pretty thick ali and an unknown alloy. You may need a serious amount of current to get penetration, and the weld will need to stand up to a good amount of vibration.


albertz - 8/7/04 at 08:00 AM

I might give it a try on some scrap and then batter is senseless with a big hammer to get an idea how good a weld i am getting.

As the intake plenum is quite prominant on the engine, it may be better to get it TIG'd, purely for cosmetic reasons as much as anything.

I have two, so i might as well have a go on one of them.


andrew morrall - 12/8/04 at 06:28 AM

I came accross this product, bought it but have not yet tried it. Check out the website http://www.alumiweld.com


stephen_gusterson - 12/8/04 at 09:33 AM

its also sold under the name of technoweld.

its 'ok' on the very small jobs i have done (joining corners of folded panel flanges).

Its a bit like solder. It doesnt 'stick' well unless you stir the 'weld pool' with a wire stick. (This is recommended in the leaflet that comes with the starter kit - and you get a metal stirrrer too.)

Might be ok, but dunno how suitable it is for a big job.


atb

steve

http://www.hindleys.com/technoweld/

[Edited on 12/8/04 by stephen_gusterson]


wilkingj - 12/8/04 at 11:47 AM

I have had this Demo'd to me, and its brilliant. Ahhh but the bloke was an expert user!. However what I learnt was that you need the right blowlamp for the job, I got a Primus Sievert with interchangeable nozzles, EXPENSIVE or wot!. Nozzles £15-30 each, and the gun was £107. But its the Mutts Nutz of blowlamps. I have used it for loads of jobs not all alli welding!
When it comes to alli welding, I found it difficult. And being a very good solderer (35 yrs on BT/ GPO) I still found it hard. there is a definate technique here. But it does work and makes a good weld. The little I have used it, has produced good although not pretty results. The hard bit is trying NOT to melt the whole bloody issue!. I warmed the whole area, then used an on / off technique ie removing and replacing the flame / torch on the work area. This is what the expert did, and it takes practice, but its easier than trying to get a steady temperature with a permanant flame on the work piece.

Anyway, thats my 2d worth on this..
Reasonable results but need more practice.!!

Regards

Geoff