TIG welding aluminium

G'day,
I've recently welded my first piece of aluminium together (and on the 2nd try, I could even break it with my bare hands :) . I'm just
beginning to learn welding, both TIG and SMAW.
Now I've got a little project that I want to finish, consisting of a piece of angle aluminium (extruded), that needs to have 2 90-degree angles in it (U-shape).
Since I'm not yet very experienced (understatement...) at welding aluminium, I was wondering: can I place a small piece of stainless steel under my weld-zone, to prevent the aluminium from sagging (in case I put in too much heat). Perhaps a bit like the idea of using ceramic strips as is done sometimes in shipyard construction.
Yes, I know the best would be to get lots of practice and make sure I can do it right. However, as a bit of extra insurance for a beginner, might this help?
Peter.
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I use copper. The heat conductivity of copper keeps it from melting. Bigger pieces work better than small pieces.
Dan
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Thanks for the tip!
Will try it out ASAP. I had never heard of this 'solution' before, so I thought there was probably some reason that it wouldn't work. Still have a piece of copperplate in the shop.
In the original post, it should say 'on the 2nd try, I could NOT break it with my bare hands'
Did I mention I fell in love with my TIG machine? Beautiful process, TIG compares to stick welding as finger painting to calligraphy, IMO :)
Just welded two stainless steel rivets (M4) together (on top of eachother), with 3 tiny 'spotwelds', at 10A. Wow...
Also, good to hear that even the pro's burn through every now and then (my ego feels a lot better now)
Peter.
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Hi Peter, I run into the same problems with making intake manifolds quite often. The guy who taught me most of what I know showed me that using a sheet of copper (bare, plain copper sheet- available at almost any chain hardware store) can be used as a "burn-through plate" Not only is the copper an excellent electrical and thermal material it's easy to bend, cut or whatever you need to make the weld joint cleanly. I don't know if this is a recommended practice but it's definitely helped me out in a pinch more than once. I see even the *best* welders burn through. They all say it's part of the game and to be expected. (Now this is from Union guys so I fully believe them).
I hope this helps,
Rob Fraser
Fraser Competition Engines Chicago, IL.

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peter snipped-for-privacy@hotmail.com wrote:

I often use stainless steel backing plates for aluminum welding and copper for steel welding.
Ted
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Wanna see something cool???
Try using stainless steel filler rod on aluminum.
It makes real pretty colors and as it cools the whole area will start fracturing. It makes lots of noise.
I found this out by accident one day, but since then I do it just as a cool TIG demo.
--
"I love deadlines, especially the wooshing sound they make as
they fly by" - Douglas Adams
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wrote:

I once mistakenly used as stainless steel filler rod instead of a tungsten. How it escaped me when I was grinding the tip is beyond me. It puts on a quite a show too.
Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
void _-void-_ in the obvious place
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With the common reaction time - oh - hope not a beer on the table :-) - I bet there was a sparkler sending hot metal in various directions waiting to be stopped.
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder
Boris Mohar wrote:

-
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Argon gas. Just enough heat to wet the bead area. Apply the filler metal. The heat should be just to tackyness a little hotter. You need to keep heat sinks away. Keep the heat above tacky only. For deeper penetration only a little more heat to full penetration. You'll see. A 10 lens in your helmet for up to 5/8 inch. 1/8 inch filler metal. Use the thumb control for more independent application. Heat sinks will burn your hand through your glove. Buckskin gloves. Use clamps if the joint will warp. Tack in places. Backstep for less warpage. Re:

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Thanks for the explanation.
Have just tried my hand at welding again (a piece of 2mm thickness and one of 1.5mm). The problem seems to be that I get 2 separate welding pools, that I have difficulty joining together in one pool. Once I get one big pool, it's relatively easy to work your way further down the workpiece.
In the mean time, this thread gets to be printed out for future reference.
Peter, The Netherlands.
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