Joining 6063 with unknown alloy?

AndersK · Thu Sep 25, 2014 2:17 pm

I will be welding 6063-T6 tubes to unknown aluminium alloy.
It is some deck chairs with kinked tubes that I will replace.
I dont have the chairs yet but is there a way to get any idea of what they are made of?

Am I assuming correct that 5356 would be the best choice of filler if I have 1050 4043 and 5656 at hand?

Thu Sep 25, 2014 7:09 pm

AndersK wrote:I will be welding 6063-T6 tubes to unknown aluminium alloy.
It is some deck chairs with kinked tubes that I will replace.
I dont have the chairs yet but is there a way to get any idea of what they are made of?

Am I assuming correct that 5356 would be the best choice of filler if I have 1050 4346 and 5656 at hand?

Since it's quite likely the deck chairs are a low alloy, likely 3000- series (possibly 4000- series for a high-quality chair), you would do well with either the 4043 or 5356. Since the alloy is unknown, and the 6063 IS known, I'd lean toward the 5356, personally. As long as you cut out no more than needed, you have room to cut another 1/4" or so each way if the first attempt gives poor results, but I don't think this will be the case. Aluminum chairs are usually a lower alloy to allow for bends.

Steve S

AndersK · Fri Sep 26, 2014 4:17 am

Thanks
I'm planning to replace entire section but I will take the cut out to test on.

AndersK · Fri Oct 03, 2014 5:14 pm

Made a test today. New 6063 tube welded to the old material using 5356 for filler. Wall is 1,5 mm (slightly less than 1/16")
Once it cooled I gave it some good whacks with a hammer until it finally cracked.
I'd say this is a pass

: IMG219.jpg (47.02 KiB) Viewed 1401 times

dsmabe · Fri Oct 03, 2014 8:20 pm

Looks good, it was the parent material that broke, not the weld. Not sure but might get a little more strength watching your heat input, and then again that might be as good as it gets.

TRACKRANGER · Sat Oct 04, 2014 6:00 am

Looks to me that the parent metal was definitely the fracture point.
I don't think that lower control of heat input (if possible) would significantly change things. The wall thickness is so thin that you don't have that much choice.
I would say that that is a very good result. Nice one!

AndersK · Sat Oct 04, 2014 10:40 am

I did the actual repair today. Got it down but not looking good. Got soot and pepper corn as soon as I started the arc. Tried to do the prep right. Ground down the old welds first with a flap disk then a velcro sanding pad. SS wire brush and then acetone. Clean tungsten.
Some areas came out really good though.
Ground two beads down and they were pure inside so I think it will hold. Noticed when I took down the original beads they were full of pits inside. Base material is an extrusion, so probably different material from the test piece I used.

Need a lot more time with aluminum before I get confident with it.

AndersK · Sun Oct 05, 2014 10:43 am

Forgot to ask what settings would you use?
I set it to 70 amps, no pulse, 150 Hz and 50% cleaning.

dsmabe · Sun Oct 05, 2014 1:42 pm

That's probably pretty close to what I'd try it at.
I'd probably have the Max amps @ 70-75, use a pedal, and a little less cleaning action on my machine.

AndersK · Sun Oct 05, 2014 2:16 pm

Just tried to lay some beads on a different material to see if it behaved as bad.

Image shows some 1050A 1,5 mm sheet. I welded it totally uncleaned. It has some salt spray on it so surface is a bit corroded.
I was surprised how well it came out compared to the chair.
Tried some different rods, the 1070 is really nice and shiny while the others are little gray and dull. I dont think I can blame poor results on either argon leaks or poor coverage.

: IMG227.jpg (89.1 KiB) Viewed 1302 times