[jumpinjackflash]

OK Saturday I cleaned all my parts for my engine mount. Put everything up in the jig again and double checked everything. I'll get it tacked up. Yeah -right. There went all my practice out the window. I did manage to get 3 of the 4 main tubes tacked up. I blew out the first tube at the deep junction. Removed and waiting for more tubing to get here.

The tube angle is very near 20 degrees at the intersection. Tube is .625" x .035" wall. Washer support plate and stud tube are .068" thickness. I tried my best to keep the puddle on the washer first....but it did blow out the tube. The only reason I got the others tacked is I tilted the whole thing to where the crotch of the junction was down towards the floor on the table in a "V" shape. Maybe I am a psycho or something but it seemed easier to get a tack... a wide one but not blown out. Not quit sure if the weld made it to the root of the joint either. A solid place to start out of there on both sides I think. Used aluminum foil as a gas dam too.
Any tips as the next supports will be at a more severe angle? I hope that I have not ruined the project with a big weld in there like that. Will put up pix when I get the 4th member tacked in place....hopefully with a good tip to put in practice. I did have the torch in line with the tube...maybe should have come in a bit sideways?

[noddybrian]

Those sort of joints are always a challenge & I've never found a simple answer - the bicycle guy on here may have a secret trick or 2 he's willing to share as he does get some perfect looking small welds in difficult joints - other than that it's the usual

1 practice makes perfect as holding steady with long stick out is difficult even for experienced guys - it may also show up your eyesight needs some help with a cheater lens !

2 long stick out using a gas lens to get into the joint

3 try a long series " 54N () L " ceramic & you can shave a bevel onto the end if careful

$(KGrHqRHJBQFEzL0DlORBRsf7jlP+!~~60_35.JPG (6.83 KiB) Viewed 1195 times

4 sometimes the joint is just not practical to weld & really needs the part re-designed.

Good luck & hopefully someone else with more experience may have some additional thoughts.

[Wes917]

If it were me from the way I'm envisioning it, gas lens long stick out. It does take some getting used to, feels like your doing something wrong lol

[noddybrian]

Anything that gets the job done can't be wrong ! - it's just the answer so many times with next to impossible access joints using Tig is re-design the part or use another process ! cluster joints are far more easily welded with stick if thick enough & tube joints are far easier to oxy / acet braze if the strength is sufficient - I've said this several times but it seems people have a fetish for Tig welding where it is not the obvious or most efficient process !

[Superiorwelding]

jumpinjackflash,
Get a picture up for us to see. I should be able help you out. I have a few special cups for accessing tight places.

noddybrian- people today might have a fetish with TIG derived from the fact that many view it as a highly skilled version of welding, however in this application I don't think you want to use stick. Not saying it cant be done here, but SMAW welding 5/8" x .035 tubing, well that would be a challenge! Not everyone has oxy/acetylene to braze either.
-Jonathan

[kiwi2wheels]

If you get the long series lava nozzles, you can file the end to an angle or a V. That got me out of a pickle once where I was losing shielding.

[Otto Nobedder]

Jumpin',

Strangely, these blowouts with TIG often result from using too LITTLE current. This is a place where manual pulse will help a great deal.

An arc of too little power will not focus where you want it, no matter how fine the tungsten is ground. On really thin stuff, I like to set the machine high, say 100A for your thin-wall tube, and use very short "mashes" of the pedal to concentrate heat where it should go.

Give it a go on some scrap, at your 20* angle, and see if it works for you.

Steve S

[jumpinjackflash]

OK here is one of the not so mean junctions...but was still a big pain in the a$$ to get tacked without blowing out the tube. Still learning but this is a hard time for sure. I have one at the 20 degree angle...the last tube. I may try some .045" filler and let the puddle get wide as it wants and just try and keep it off the thin wall as long as possible until it needs to. At least that is my plan....I am probably wrong though. Tried a couple things tonight but sleeting ice pretty heavy covering my shop now and the heat just doesn't maintain a warm set of feet. This has turned into a real bugger to mate up for me. Frustrated with it now. This has a gap at the bottom....just going to have to let it be filled...out of steel again. I'll cool off and look at it again in the weekend......my biggest fear now is blowing a tube after getting on with it and making some progress.

[Wes917]

Yep I'll stick with my above, gas lens little longer stick out, and letter rip tater chip

[power]

Another thing to consider is maybe a flex head or swivel head torch to help you get a good position on hard to reach areas. Custom fit your nozzles helps too. Good luck

[Superiorwelding]

Jumpin,
I know how you feel being frustrated that you cant get something that should be easy. I would have to agree with the ideas posted already. I will take a pic of a set up I used a week ago that worked well for accessing a tight spot, although I think it is the nozzles in the picture.
Not knowing the application and taking into consideration your frustration, would this be better to MIG this joint? There are tapered nozzles and longer tips that you could use that I think would work out just fine. If you have access to a Pulse MIG, that would be ideal for this application, in my opinion. Just a thought.
-Jonathan

[jumpinjackflash]

I wish I had other options...I only have the TIG machine. It would be easier MIG....but I think after getting a tack I can start on that and come around the tube on that thick washer. You think that is a good starting point to come away from there? After watching Jody's video on a similar piece he did use this for a restart place. He was also using the same thickness material...so a little more problem for me to overcome. I do know a guy that works at Deere Hitachi and their machines run .045" wire at 700 IPM. Heavy duty plate. I only have access to older MIG machines at work. Nothing fancy and most in need of repair of some nature.....not a good choice for me.

[zank]

Tough indeed. I'll post again later with a few pictures, but a couple things come to mind.

Try tacking more on the sides. A couple of tacks on opposing sides should hold your alignment.

If you need to tack deep in an acute angle, don't be afraid to bridge a little. When you are running your bead and carrying a puddle later, it will be easier to wash metal down into the root. You'll consume the tack in the process.

Get a good puddle going on the thick piece and bring it over to the thinner tube.

You'll get there!