What Settings

[Big_Eddy]

I'm pretty green when it comes to TIG, so would appreciate some guidance.

Need to weld up some 22ga 304 stainless pans. Mostly 6" corner seams with perhaps a few longer ones. Seams have to be watertight when I'm done.

I have a Maxstar 150 STL and will buy Stainless filler.

What would I expect to be using? Tungsten type and size, amps, Argon cfh, filler type and size etc? Any tips, pitfalls, suggestions. I assume I will need to stitch weld but it would be convenient if I didn't.

I have lots of scraps to play with so will practice a lot before I start the final project. (Arc time is arc time - even if it is just welding 2 3" squares together - right?)

And - would I be better off with MIG instead? I have a HH210 and a Lincoln 110V. Pros and cons of MIG versus TIG for this task?

[tailshaft56]

I'm pretty green on stainless but I'll give it a shot. The settings for argon will be the same as mild steel. I would use a 1/16 tungsten or maybe .040 if you have it. not sure on the amps but if it were me i would start around 50 and tweek from there. The weld shoud be back gassed or at least use the welding paste to keep the backside from sugaring. keep you heat down as much as possible. SS will cook to crispy critter pretty easy. When you get it right you should have a nice bead with a little rainbow coloring around the bead. If it looks dark dingy it's fried. Others will probably have better advice but maybe this will get you started.

As for mig I would think it would have to be done as a series of spot welds. My preference would be tig for this one.

[enlpck]

I'm pretty green when it comes to TIG, so would appreciate some guidance.

Need to weld up some 22ga 304 stainless pans. Mostly 6" corner seams with perhaps a few longer ones. Seams have to be watertight when I'm done.

I have a Maxstar 150 STL and will buy Stainless filler.

For 304, 308L is a good filler to use (or 308, but 308L is less succeptable to several problems, such as carbide formation, which will reduce corrosion resistance in a bad way) Filler size can be whatever you are comfortable with. Thick is easier to handle and easier to find, but you don't really want a filler thicker than the material if you can avoid it. I would go with 0.035 or 0.045, if you can find it. In a pinch, you can use MIG wire of the appropriate diameter, but you will need to straighten it and it may still be tough to handle. 1/16 will do it, but is a wee bit heavy for my taste.



What would I expect to be using? Tungsten type and size, amps, Argon cfh, filler type and size etc? Any tips, pitfalls, suggestions. I assume I will need to stitch weld but it would be convenient if I didn't.

I'd run this at about 30 amps for the outside of the corner, and a bit higher to fillet from the inside. The outside is a lot easier. Adjust as needed. Hotter and faster is better than cooler and slower. If you can set up a guide for the torch to follow, life is much easier. Try to lay the wire as flat to the joint as you can, in line with the joint, and practice with different feed techniques. I sometimes slide the filler back and forth in the groove for a weld like this, rather than lift and dab. Just laying the wire in and running it over sounds easy, but may lead to problems. (see http://www.millerwelds.com/education/tech_tips/TIG_tips/hints_tips.html, about half way down for corner joint)

I'd go with a 0.40 (or 1/16", if you don't have 0.040) thoriated (red) or 2% lanthanated tungsten. With the 1/16, I'd grind a long taper (maybe 4:1) for part of the way, then the standard 2:1 near the end, and put a small flat at the tip (maybe 0.010" dia), so that the 2:1 and 4:1 are about the same length. The long then short taper helps a little with starting and control, since the 1/16 tung is really a bit large for the current you will be running. (3/32 is WAY too big, despite the rep for being universal.)

Cover the back with solarflux for about 1" to either side of the joint.

You may need to clean up the weld area to restore the corrosion resistant properties. Depending on the service that will be seen, this can be done mechanically or chemically, depending on service requirements. (see http://www.assda.asn.au/asp/index.asp?pgid=17977, for example)


I have lots of scraps to play with so will practice a lot before I start the final project. (Arc time is arc time - even if it is just welding 2 3" squares together - right?)

And - would I be better off with MIG instead? I have a HH210 and a Lincoln 110V. Pros and cons of MIG versus TIG for this task?

If it needs to be liquid tight, I'd go with TIG. Plenty of people would go with MIG, but I prefer TIG. MIG tends to put in less heat if set up right, TIG gives more control over fusion.


There are a few people here that do sanitary and kitchen SS work regularly and will have more to add. I have done jobs like this, but it isn't everyday work for me.


To give you an idea, the pics are of 0.010" thick razor blades done by hand, using 0.040" 308L, dabbed, and a 0.040" thoriated tung, at between 10 and 15A, using a Maxstar150. Used fixed current with remote finger switch. No solarflux on the back. You can see the sugaring from the lack of protection. (Ya, I gotta show off once in a while, but it shows what you can do with thin material)

[Big_Eddy]

Thanks to both enlpck and tailshaft56 for their inputs.

I thought I would give it a try on mild steel first - 22 gauge. I used Red 1/16" with 30 amps on the dial, but turned down a bit at the thumb.

I only had 1/16" filler, but I also had 0.030" Mig wire. I actually found that once I got the arc established, I really did better without using filler. I found that with tight fit up and about 10-15 thou overlap of one piece to the other, I was able to use that overlap as filler material by melting the edge back to the lower piece. (I was running horizontal - had my 2 pieces forming and upside down V)

Starts were fun, and I needed to remember to slowly reduce the heat as I went along, otherwise I got a nice blowout at the end of the seam, (that's where I used the filler)
I was pretty pleased for a novice. Pictures will come.

I have a 0.040 Red tungsten so may give that a shot next still with mild steel. When I have done a few more coupons and think I have the idea - then I'll try some stainless. Thanks for the help.

[Big_Eddy]

Here are a few quick pictures . Sorry about the size and focus - webcam won't focus close and my real camera went to school with my son.

It is watertight - but only after I fixed a few holes. Most was done without filler - I clearly need some 0.040 filler, as 1/16 is too large, and 0.023 evaporates! When I did use filler- I ended up with large bumps.

Comments and suggestions are welcome. Try to get some better pictures next time.

[whateg0]

Far from expert Tigger here, but I'd expect the 0.023" filler to work great for this. It's small enough to keep from cooling the puddle too quickly. You do need to feed more of it (length) into the puddle though.

Dave