Hi gents, require assistance with thin SS

Hi guys,
New member here so g'day to you all.

I have a protig pulse tig thats a pretty nice bit of kit, I bought it a while back to weld some hand rolled tubes and cones n stuff. However, the stuff I need to weld is only 0.5mm and I seem to have continuous problems with one side melting off before i can join the two with the weld bead and it just makes gaping holes.

If I drop the amps soon as I dab my filler it just leaves a blob that wont melt... so frustrating. I got some solar flux that did help, but what I really need is a video, or a 1 on 1 (or 1 on All of you ) for how to set up my pulse tig, duty cycle, hi/low amps and pulse rate so I can nail this stainless weld. Any suggestions please take the time to respond it is quite important to me.

Also note I can only get 1.6mm filler rods here, both steels are 304, I always clean with a wire brush and solarflux the backside which is just awesome. Someone help!

Cheers guys for your time.
Smokeyjim

For thinner filler wire I buy a small reel of stainless wire intended for use in a MIG Welder
Cut a small amount off and Bob's your Uncle

Andy

Thanks for the reply, I do have some 316SS but it worked really badly, if I can find some 304 I will definitely give it a go, in Australia its pretty hard to get good welding supplies.

Also tell me, I've heard two things from welders regarding the tungsten, (I use thoriated)... one guy says grind it into a point, the gently grind the tip of it flat, another says go with a straight point. I only just tried it with a flat tip an hour ago and seemed to work pretty well, no where near there yet, so Is there any other ideas?

0.5mm stainless with 1.6mm filler is never going to work well, if at all. 308 is the correct filler for 304 parent material but 316 should work fine- it's used all the time. There must be somewhere in Aus that carries 0.8mm filler or at least a mini roll of 0.8mm MIG wire (should be a lot cheaper!)?

Thin stainless is often welded autogenously (without filler) but fit up needs to be perfect. With a little practice you can get very good results, especially with pulse

Pulse settings are mainly personal preference but...

If using filler then you'll really need at least 50% pulse width (or duty cycle) to give enough time to add filler during the 'peak time'. Frequency would be typically in the 0.8 - 1.6Hz range but is dependant on travel speed- looking for around 70% overlap of the peak pulses to prevent defects. I'd set the background (low amps) to around 40% of peak as a starting point.

If i needed say 18A then i might start with 26A peak, 10A background, 50% peak time and frequency of 1.2Hz

The peak and background amperages can be averaged out to give, err, an average current. Basically as the background is reduced either the peak amperage or pulse width need to be increased to keep the average current right. There's a free pulse parameter calculator here, bear in mind that this site is really based around automated/orbital kit though

If welding autogenously then you can get more radical with pulse settings- much higher peak amperages and very short pulse widths combined with a higher frequency put very little heat into the weld. This is typically the only way i use pulse

Putting a flat on the tip of the tungsten isn't necessary here. It's often used on automated kit for several reasons but for manual welding the main benefit is less chance off the tip melting off at higher currents and/or longer tip life

I hate doing stuff that thin. Use of a chill behind it might be usefull, take a bit of heat away.
The filler, as said, its too thick, 1mm would be more like it, a dab at the start and the rest ought to flow nicely as long as its a nice fit.

Guys hope you all had a happy new year and a wonderful christmas.
I just wanted to say thank you all very much for your help and I think i'm finally getting somewhere with this thin stuff. Thanks a lot everyone and make sure you have a safe and happy holidays.

Take care,
SJ

pules calculator

hi can you please send me the web site so i can get the pules calculator. thank you . mark@lynnh.karoo.co.uk

With it being stainless, i'd either put something on the back and clamp it to it or use a purge setup, (much more difficult). Make sure there are no gaps at all before you start. You'll probably have to start with filler, but without gaps and no prep you should be able to zip along with a fast pulse without using filler.

Alternatively as suggested, use some stainless mig wire as filler.