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SCrazy
05-15-2011, 06:49 PM
Been a long time since I did any TIG welding, and even back then I didn't do a ton and only on steel....Well reworking my IC, Blower Top and IC tubes is becoming quite the adventure.

Welding on the top and IC where the material is about 1/8" thick was no problem....came out acceptably well, BUT......

The 2mm thick IC tubes are about to drive me NUTS!!!!! I need lots more practice before trying anything final....I can't get the puddle to flow across the joint then when I do I wind up blowing through the wall more often than not....aaarrrgggg.

Running at about 50amps with 3/32 tungsten and filler. I have found some success when I sharpen the tungsten and work with a smaller more focused puddle but still no pretty.

I no Ken that's for certain.

CMac89
05-15-2011, 08:20 PM
The pointed tungsten is the only kind I'll use. What kind of tubing is it? If it's the cheap eBay tubing, then it isn't a good metal at all. I'll set the welder up where I can floor it to create the puddle and then back off to half pedal, once the puddle is built up, to start adding filler rod. It's difficult to get the hang of the right heat to filler rod combination, at first, but it sounds like you aren't adding enough rod and too much heat.

XR7 Dave
05-15-2011, 09:41 PM
Starting is the hardest part because the flame only wants to go to either one side or the other. Build up a substantial pile/puddle on both sides, then bridge between them. As soon as you have a bridge, stop. Now the two sides are joined and will transfer heat between them. It will go much easier from there.

As Casey said, add more rod. I find using 3/32 rod works well for 2mm tubing even though it seems too thick and the reason is because it lets you fill the gap quickly and absorbs enough heat to keep the thing from falling apart. Hard to explain correctly, but that's what I use. You have to move somewhat quickly and keep the rod flowing!

Oh, and the 2mm Ebay tubing welds great. If you are having trouble its because of other reasons.... ;)

nmcbchief
05-15-2011, 10:00 PM
Just do as Dave has said about going from one side to the other. If you could get a foot control to adjust amperage would be the ideal tool when welding thin tubing.

SCrazy
05-16-2011, 07:33 AM
I think what Dave described is pretty accurate for me. Arc jumps side to side across the joint allowing me to form small puddles on either side...however when I add filler to the two small puddles it doesn't flow but rather I get a big glob of death sitting on one side of the joint and it takes a tremendous amount of heat to get that puppy to flow out....and by that time I've often blown a hole in the tubing.

I've also found the peddle technique to be very important once the puddle is established....it takes alot more heat to get started than to actually run the weld.

shoalcracker
05-16-2011, 01:58 PM
What welder and tungston are you useing?

On first read you may want to look at a smaller filler rod and tungsten (.062)

Each should be close or smaller size for thin wall welding (rod and tungsten)

Grind tip to 45 degrees. Allow a little more time for heat buildup for puddling.

Also tungsten should ball no more that 1.5 times of the (tungsten.)

Hopefully foot controlled, and if so, the above posts are applicable. (higher heat then back off)

If not foot controlled a lower heat and wait it out.

Paul
(from Nick- HT Eng)

the-big-e
05-16-2011, 05:07 PM
It will help if you preheat the parts before welding.....

If you cannot do that, then arc off on the parts and use the arc as a kind of preheat.....

It might take a minute or two before you get a good puddle going....

And you need to be using the green 100% pure tungsten as your electrode....

SCrazy
05-16-2011, 07:30 PM
Using an older Syncrowave with pure green 3/32 tungsten electrode sharpened with a blunt tip to about 50% diameter. I get a nice shiny little round tip but not a big blop Qtip looking ball.

I am going to try some 1/16 filler and see if that helps. I was using the tungsten with just a blunt balled tip and I've found that sharpening the tip definately helps focus the arc.

I also think I'm being to timid feeding the rod initially as it seems to want to ball up before it gets to the little puddles even if I'm very careful about my torch and feed angles (happens even with torch angled AWAY from the filler). I've been told I should try jambing it in a little more agressively.

I haven't tried preheating yet...with the stuff so thin I didn't think I would need to but anything is worth a try.

XR7 Dave
05-16-2011, 07:33 PM
No need to preheat that material. Remember, you can't get the filler rod in the path of the flame. You have to introduce it directly to your puddle.

SCrazy
05-17-2011, 08:30 PM
Got my hands on some 1/16" filler and things went much much better tonight. I was consitantly able to get the puddle to bridge the joint and start flowing. Welds were much more uniform as well.

I'm a happy camper......I think with a little more practice I'll be ready to do some "real" welds.

Jacob_Royer
05-28-2011, 09:08 PM
Clean Clean Clean! that is the secret to welding alluminum!

Stainless steal wire brush is your friend! brush the hell out of anything alluminum you weld! also if you stop and start again it doesent hurt to clean your surface again! I prefer a 1/8" green toungsten for alluminum. I switch the welder over to steal and arc off a piece of scrap and mash the pedal all the way down and pull it away from the scrap. This puts a nice ROUND end on your toungsten! which is what you need for welding alluminum. Also they make some stuff welders call Pixie Dust (not sure what the actual product name is) but it allows you to EASILY put a nice round end on your toungsten and its very cheap! Take your time and apply heat slowly at first, listen to the sound your arc is making! It sounds kinda like bacon frying but faster when you have everything right. Also watch the two surfaces you are welding together they should both look shiney! that is the point where you can start adding filler rod! I like the drag the weld twords me, you can get a nice rythm going where your heated surface sucks the filler rod in as you go. One more thing when pre cleaning use a STAINLESS BRUSH ONLY! cleaners can royaly screw up your weld by contaiminating the surfaces!

SCrazy
05-29-2011, 06:22 PM
What do you do when the puddle get contaminated and you get a "pond skum" on top.

Stopping cleaning and restarting doesn't seem to work real well.....do you need to grind out the puddle??

Once the puddle is messed up it's hard to get things flowing again.

Dirtyd0g
05-29-2011, 08:23 PM
I don't do aluminum but I know with steel if you get a puddle of junk you have to grind it all out as it contaminates anything you put on it. Either that or lay a huge fast puddle over it before it can get contaminated.
Alan

SCrazy
05-31-2011, 07:38 AM
Most of this welding is on Aluminum IC tubing.....

I think the contamination is coming from inside the tubes. I've noticed it seems to happen most often when I have heat right on the joint and I overheat the puddle a bit. Things going along perfectly...a little to much heat....then BAM pondskum.

Also when tacking before I really clean the tubes up I've noticed I get nice bright puddles when I focus the heat on either side of the joint but once I put heat right on the joint it's prone to getting dirty quickly.

I tried cleaning the insides of the tubes with some Laquer Thinner and that seemed to help a little (at least in my head) but certainly didn't cure the problem entirely.

Jason Wild
05-31-2011, 08:48 AM
Do you have a tig welder you can adjust the clean seting on? Might want to try it set to a little more clean then auto will give you

SCrazy
05-31-2011, 09:22 AM
My machine is a 10 year old Syncrowave that doesn't have that adjustment feature.....I don't mind cleaning by hand but I have found the right technique yet.

XR7 Dave
05-31-2011, 02:36 PM
You almost answered your own question Brian. You most likely got the weld too hot and burned the aluminum. Once you get burnt material into the weld things just get ugly. You can work the spot to bring some of the contaminants to the top or you can flood over it to seal it up. Of course this isn't a structurally sound way to deal with the problem, but sometimes if strength isn't the most important thing you can cover things up and move on. Be aware that you most definitely won't be able to grind/smooth the weld after you've had that happen though.

Grinding it out and starting over can be messy too.

SCrazy
05-31-2011, 03:14 PM
Well...one thing I do know is that I've burned or melted just about everything else in my garage so it wouldn't suprise me if I burned the aluminum as well.

Good news is that I'm getting better at spotting when things are about to go to crap and I'm able usually able to stop before things get too messed up.