[FitNPipe]

Ive got some .035 wall 1/2" 304 tubing to weld to a substantially thicker 304 fitting. Its a socket weld, and I'm using TIG, I was just trying to figure out if I should match my filler wire to the tubing? Or is it manageable with 1/16th wire? I am on the verge of ordering some .045 wire since my LWS doesnt carry it.

[Poland308]

Is it a SS socket fitting? If so I’d use 308 or 316. If it’s a carbon forged steel fitting and SS tube then it would be 309.

[Oscar]

I tried doing the same thing a few years back when I did some work on my fuel pump for the race car.






If it's anything like this, you will want no bigger than 0.045" and MAGNIFICATION ! I recommend a long 4x taper on the tungsten with a tiny flat on the tip. If the fitting is not attached to anything, put it in the oven and pre-heat it, because it will be wayy too easy to blow through the 0.035" tubing, as I did many times. Don't use too big of a tig cup because then it might force you to use an incorrect angle.

Man, those were the days. I think I used my Eastwood TIG 200AC/DC for that. Good times, lol.

[noddybrian]

If it is anything like Oscars project I would have used silver solder or silver braze - eutectic make an excellent pre-fluxed rod for this type of application - it flows & into the smallest of gaps & is ideal for this kind of work - sometimes old school oxy / acetylene still works best.

[cj737]

Ive got some .035 wall 1/2" 304 tubing to weld to a substantially thicker 304 fitting. Its a socket weld, and I'm using TIG, I was just trying to figure out if I should match my filler wire to the tubing? Or is it manageable with 1/16th wire? I am on the verge of ordering some .045 wire since my LWS doesnt carry it.

I would use 0.045 or smaller since the tubing is what you need to hold, not the socket. Purge if possible will help greatly. Some fusion tacks, then a thin bead with the smallest wire you can lay your hands on. If you use the 1/16th, wire you’ll need more heat than the tube will tolerate to melt the filler. Cup size and stick out is up to your style of welding.

[FitNPipe]

Thanks for the responses. I have the option to order some .035 wire, so I'll go that route. It will have a purge on it, and I'll preheat the fitting a little. I was provided a piece of scrap to get my heart right so that helps

[Oscar]

If it is anything like Oscars project I would have used silver solder or silver braze - eutectic make an excellent pre-fluxed rod for this type of application - it flows & into the smallest of gaps & is ideal for this kind of work - sometimes old school oxy / acetylene still works best.

I agree. If I had to do it all over again, silver solder would be the way to go. TIG'ing a joint like that was a pain.

[FitNPipe]

I picked up some .035 wire and tested amperage on the extra piece. I set my machine to 75 amps and hooked up the foot pedal. Im using a 3/32 2% thoriated tungsten. I put my ground on the fitting and lit up on that with really low amperage to preheat it a little before moving to the tubing. I put a short weld on it to make sure things would melt together and had good success. The purge is working nicely and i should have no problem as long as I make very short welds and let things cool down. I'll post some pics later.

[FitNPipe]

As promised. .035 304 tubing to 304 compression fitting. Set machine to 100 amps and used foot pedal, never maxed out the pedal. I used .035 308l wire and purged the piece. 3/32 thoriated tungsten sharpened to a needle point. I ran 2 passes because I knew I was running cold since I was afraid the wreck a 300 dollar coil and didnt want it to leak. It could be better but I'm happy with it.

[JayWal]

What size is the nut on that fitting?? Is it as small as it looks?