Welding Tips and Tricks

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.

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.

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.

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.

FitNPipe wrote: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.

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

noddybrian wrote: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.

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.

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.

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