[aclundwall]

I have a new exhaust header for my motorcycle. It took forever to get it...and once it got here, one of he spring anchors had come loose, and a couple others don't look to be very solid. Kinda weird, actually, cause the exhaust is pretty well constructed otherwise!

Anyway, I want to reattach this anchor, but I'm pretty new to TIG. I've been having some problems and thought I'd try here for some ideas.

The exhaust itself is stainless, though I don't know for sure what type. Tube wall is .035" thick. The 'anchor' is nothing more than wire about 3/32" thick, bent into a U-shape and tacked to the tube.

For equipment, I've got an Everlast PT210ext, and a Hobart Handler 210mvp. I've only tried the TIG so far, assuming that would be the best option, but now I'm beginning to wonder!

I haven't tried welding the exhaust itself yet, of course...I've been trying to practice on some .050 stainless sheet. If I can get it done on that, I've got some .035" wall tube to practice on next.

I just can't get the wire to weld to the sheet! I got some 3/32 stainless rod at the hardware store, and I just cannot get it done. If I get a puddle on the sheet and then try to join the rod, the rod just gets red hot and sits there.

On one of the motorcycle forums, a guy detailed his exhaust build...he did exactly what I'm trying to do, and he just used 3/32" 308l welding rod for the spring anchors, and it worked great. So I tried that, and failed miserably! Any heat at all, and the wire melts away! I know...what a shock!

I have no trouble putting a bead on the sheet! But I can't get that darn wire attached no matter what I try!

I started with my rig set on 35A max (I'm using a foot pedal). When that wasn't working, I tried settings similar to the guy I mentioned above. I used pulse, 60% on, 10A base, and I tried various frequencies. I ran some nice beads on he sheet, but still no go on getting the wire attached to it!

I'm using a CK17 torch with a gas lens, and a 1/16" lanthanated tungsten. Argon set to about 7 lpm.

Any ideas? I'm pretty much willing to try anything, since I'm not welding on the actual exhaust yet.

[rick9345]

I use an additional light gauge (12)ground with alligater clips on the u clip, with pipe well grounded. Press the 2, tight together and light up on the heavier wire(heat wire/pipe) and then wash the wire on to the pipe.

[aclundwall]

I use an additional light gauge (12)ground with alligater clips on the u clip, with pipe well grounded. Press the 2, tight together and light up on the heavier wire(heat wire/pipe) and then wash the wire on to the pipe.

Good idea...ground both. I'll try that. Wash the wire on to the pipe...Do you mean fusion weld the two, as opposed to using welding rod? And when you say wire, are you referring to the welding wire or the stuff I got at the hardware store?

Thanks very much!
Art

[zank]

Light up on the end of the 3/32 wire and basically use that as your filler. But instead of using the hardware store wire, I'd use a piece of welding wire like the other guy did.

[RichardH]

Wash the wire on to the pipe...Do you mean fusion weld the two, as opposed to using welding rod? And when you say wire, are you referring to the welding wire or the stuff I got at the hardware store?

For what it's worth, my experience is very limited, but I've been building wireframe using 1/8" and 1/16" TIG rod as my material, fusion welded together.

On fine joints, I've found that pulsing (1-2 per sec) gives much better results because the arc is much more willing to move between pulses, while it will cling to the puddle if you use steady current. So, it's easier to move back and forth between the two parts to get each to puddle, despite their differences in mass. Eventually they're both wet enough that the puddles join.

Working with thin material, I find there is a fine line between the point at which they are molten (but retaining their shape), and adding just a bit too much heat at which point surface tension causes it to ball up and retract / burn through. Your thinner material (the header) is larger in mass, so my concern would be figuring out which of the two needs the most heat without making a hole in your header.

I light up on the heavier material right at the joint, get it to puddle, and wash it close to the lighter part. Meanwhile there is some heat transfer to the lighter other part, so it puddles quickly once the arc is moved onto it, often while the heavier material is still wet, and the puddles bridge together. Sometimes it takes a little coaxing back and forth.

For current, I set the max for the thicker material and use a pedal to ease up for the thinner material, but use machine pulsing. I set the current just high enough that it takes several pulses to puddle it, which keeps me from accidentally blowing it away.

If you're using filler rod as your material, why not wash the end of it into the base metal, instead of adding more rod?

For what it's worth,
Richard

[aclundwall]

I made some progress tonight. I tried adding a ground to the anchors as suggested, and that helped. But actually clamping the anchors to the base metal helped more. I actually made up some of the actual spring anchors, and used a set of needle-nosed vice grips to hold them more firmly.

I also tried a whole bunch of different settings, tungsten, nozzles, etc. I wound up with my max amps at 40, 60% duration, 50% pulse current, 2Hz pulse.

The big surprise came when I tried a 3/32 tungsten electrode. Till then I'd been trying 1/16th and .040 electrodes. Things got a lot better when I moved up to he bigger electrode, and I'm not sure why that is!

I graduated up to welding these on some 1" x .035" wall tubing. It was actually easier that attaching them to the .050 sheet. I'd weld three or four one one end, then chop the end off and do it again. I tried pulling some of the last ones I did loose, and the held fast. But they're still ugly...more practice is necessary. But not once did I blow through the tube, so that's good at least!

Art

[zank]

I'm looking forward to getting a machine with pulse. Seems pretty handy.

[rick9345]

watch Jody manual pulse with finger sw or pedal.
luxuary is having a pulse machine and seldom if ever using it.

[zank]

Yeah, I've been pulsing with the foot pedal on aluminum lately. I still like a steady current on steel and titanium. But I'm getting used to it on ally.


aluminum macro by Zanconato Custom Cycles, on Flickr

[NYWELDERJim]

I know it has been discussed a lot on this site lately but how are you prepping your tungsten electrode? I have found for welding small parts like the ones that you describe a tip with a 30 degree included angle works good. I don't know why you are getting better results with the 3/32" dia. electrode, I would have used a 0.040" or 1/16" dia. electrode for the parts you described. You have a excellent approach by practicing and developing the process on scrap/practice metal before attempting the real parts.

Jim

[aclundwall]

I am sharpening the tips to a point, and I'd say an included angle of 30 degrees is pretty close to what I have been getting. Of course, I'm sharpening them the correct way (lengthwise, not crosswise).

I practiced more tonight. I did go back down to a 1/16th tungsten, and was doing OK. I'm going to try a .040 tungsten tomorrow.

I took some of the cut-off ends and fusion welded them together, just for giggles. That's kind of fun, though I was having some trouble seeing the joint clearly. I totally forgot that my helmet's darkness can be adjusted:-). I just screwed it to maximum and forgot it!

I saved the settings I was using on my welder. That sure is a handy feature!