Small TIG Welds

[RHschecter]

I'm a media blaster and I see a lot of differn't size and types of welds. I also own a Syncrowave 200. I see welds on things like piper cub planes and a lot of stainless steal food machinery that are realy small maybe 1.5-3mm across. Today I took home a stainless sink out of the scrap bin and cut it up, and The smallest weld I can make on it is ~4mm. How are these small welds made? I'm trying to do this on a Fillet T-joint.

[fun4now]

with a smaller tung. and cup, or with a inverter and a smaller torch, or an O/A setup with a small torch. it realy all depends on the situation and the welder doing the weld.
i think the syncrowave came with a W17 torch, replace that with a wp50 or mt 125 micro torch, like in the link or the pic posted.
http://www.arc-zone.com/catalog/web_...=6892375_53099
turn down the amps and go for it. its all about the right tool for the job.
the syncrowave is a great TIG unit but as its a transformer it will have a little larger arc than an inverter but can still produce some fine welds, but with a 3/32" tung. you can only get so small. you might try going down to a 1/16" tung. i dont know what came with the syncro200 but you can always get smaller tung. and cups as well as a smaller torch if the job calls for it.

[fun4now]

almost forgot, welcome to the board

[youngwelder_154]

I wish I could help you with your question but unfortunately I'm not very knowledgeable with TIG welding, But as fun4now said welcome to the bord I really hope you enjoy your time on this site. I know the guys on here have made my time on this site enjoyable and everytime I leave this site I know a little more then before I signed on

[RHschecter]

Thanks. That mini torch is interesting. I was using a 1/16th, The Sycro200 comes with 3/32nd. Thanks for clearing things up for me.

[tsalagi]

hey, don't forget the filler rod size. i've seen razor blades welded together at a lincoln seminar. it looked like the filler rod was smaller than a strand of hair. one of the coolest things i ever seen.

[Danny]

I have a tiny little flex head torch,rated for under 100 amps, and run a 1/16" tungston. I still use 1/16" filler but have heard of guys using mig wire as was discussed a few weeks back. I know you probably did this, but make sure you have a really good clean sharp point and a small cup that will allow you to get in close and personal.

[fun4now]

they bring up an exilent point about the filler wire. some things can be welded without any but always remember to use filler when doing aluminum. the heat of welding burns out some of the chemical make up of the aluminum and without filler it will not hold. magneaseum and silicone burn out fast and need to be replaced. filler wire is higher in thease 2 components to insure a good suply to feed the starter metal. 4XXX series is higher in silicone and 5XXX is higher in magneseum.
i have used MIG wire for filler befor with good results. i dont know what the $$ breakdown would be as fare as witch is cheaper in the long run to use, probly MIG wire, but if you run out of filler you can always grab a few ft. of mig wire to finish up, so keep that in the back of your head incase you need it. nothing worse than running out of filler with only a few inches left to weld.

[JonnyTIG]

The only aluminum alloy I ever welded successfully without filler was 3003. Aluminum Manganese alloy. Many high end truck tool boxes are fusion welded when using 3000 series material. Other than that specifically, I've never had success with other aluminum alloys. Thanks for the info Fun4now.

When I worked at Rocky Mountain Bicycles we used 0.035 ER70S-6 wire to weld the Cr-Mo frames. I've used .023 gmaw wire for making super small welds, 1.5 -2mm in width.

[etonline]

I use 040 red tung. on thin SS you can get collets that small for the 17 series torches from Arc zone

[down19992000]

at work we do plasma welding with a thermal dynamics welder using 3/32 tungsten welding eight thousanths stainless steel. pain in the a$$ to learn but leaves a pretty weld

[Rocky D]

I realize this is an old thread, but I didn't see anything about technique in producing small welds...we must do this in aircraft welding. In this project, I had to weld a 321 stainless fin .030" to an oil tank that was .035" thick, and have no penetration to the back side...I have never used a tungsten smaller than 1/16" and wire size of .030"...this is the trick...first have a copper backup purge for stainless, and force the rod into the joint, and carefully walk up the rod, leaving a .050" weld...you need good eyes, steady hand and good concentration to do it...soon it will become second nature.

[MadisonHotRods]

Could you explain this "copper backup purge for stainless"? I am familiar with back purging with argon gas only. How is this copper used?

[Aerometalworker]

Could you explain this "copper backup purge for stainless"? I am familiar with back purging with argon gas only. How is this copper used?

I think he meant:

Copper backup , purge for stainless

Meaning use a copper backup....and purge for stainless. This is pretty common for thin stainless work like that.

If im wrong I appologize

-Aaron

[batchelc]

If your thinking about doing thin tubes (like on the piper cub) then the WP-225 torch is worth looking at. It has a flexible neck and you can change the heads out with your gloves on. You can also buy 45, 0 and 90 degree heads:

http://www.arc-zone.com/index.php?ma...cPath=13_18_42
http://www.arc-zone.com/index.php?ma...h=13_18_42_342

Use a 1/16 red tungsten and turn the heat down (start at 50 amps). If you have good foot/finger control you can turn the heat up (75 or so) and pulse the foot control. You want to minimize heat input to the part. Either find the lowest amount of continuous heat that you can use or work of using higher amperage for shorter times (will cause the least warping).

You should be aware with thin stainless you should have an inert gas like argon on the back side or you run the risk of certain types of cracking. For flat plate parts to practice on I would not worry about this but if you do anything structural you will want to do some research first.