WS6HUMMER

iTrader: (19)

I was looking at the stainless Y pipe that Thunder built for my car years ago and the weld beads are so flat & clean that I suspect they may have fusion welded it and used on filler. Have any of you welded your hotsides with just fusion welds?

70Stang

iTrader: (2)

It is normally bes to use filler so you can get full penetration.

Some welders will do a root pass and then use a 'looks pass' to clean the weld...have you had any issues?

WS6HUMMER

iTrader: (19)

Yeah I was practicing on 1/16 plate just laying some stringers, I was using 3/32 filler and it was a bit messy like I was adding too much filler. I plan to try using a smaller rod (.045) and see how it goes.

Here's a pic of the weld that I suspect is a fusion weld, what to you think?

DMH Fabrication

iTrader: (126)

Like 70stang said, you really need to use filler. Material and thickness really determines if you need a root pass. It is possible that your y pipe was tigged and they used a smaller filler rod and wider bead so it looks flatter.

Edit: I can't see your picture at work since images are blocked but I will take a look when I get home later for you.

WS6HUMMER

iTrader: (19)

Thanks, also what filler rod should I use, 308?

DMH Fabrication

iTrader: (126)

What grade stainless are you welding? 304, 321, etc.? 308 filler is correct for 304 stainless.

smokinHawk

iTrader: (48)

that pipe does look like it ws done with filler, but sparingly

WS6HUMMER

iTrader: (19)

I'm looking at some builder kits at columbia river, I could 304 or 409, whats the different & what rod do I need for 409?

Thanks, I was using 3/32 to practice and it was messy, think I'll try some .045 and see if I can make it look clean.

Fireball

iTrader: (21)

409 is magnetic and can surface rust.

WS6HUMMER

iTrader: (19)

Thanks! 304 it is.

smokinHawk

iTrader: (48)

for all the lab testing I have done on 304, that stuff is awesome.

WS6HUMMER

iTrader: (19)

Thanks, its expensive but it wont rust and I dont have to pay to have it coated.

Derek @ EDO

iTrader: (73)

You can fusion weld stainless tubing with a thickness of around sch.10
If done properly the joint will withstand hundreds of PSI.
Simply butting up two clean ends and welding them together with the appropriate heat will
penetrate the tubing creating a bead on the inside as well.

For a smooth bead on the inside of the tubing use argon as a purge.

You can add filler material as needed but be aware of the metal depositing on the inside of the tubing.

You see fusion processes performed in all sanitary food grade environments where the inside of the tubing can not have excessive penetration. This is done to alleviate the possibility of food product particles getting caught in the "penetrating weld"
If that would occur the stuck particle can spoil creating a contaminated batch.

WS6HUMMER

iTrader: (19)

Very interesting info, thanks!

ls1_chevelle

iTrader: (9)

Go with 309l filler rod, I used 1/16 filler with a orange 1/16 tungsten.

WS6HUMMER

iTrader: (19)

Thanks.

ls1_chevelle

iTrader: (9)

Your very welcome. And to explain why....

You should only have to see at max 55 amps +/- to weld standard exhaust pipe in mild steel or stainless steel form. The effective range of 1/16 tungesten is right in that range, where-as 3/32 tungsten is pushing it on the effective range, you can do it with a very long taper. But 1/16 makes life easier.

For filler rod, 1/16 is what you want simply because it makes over depositing less likely to happen. You mentioned above that you were having this issue. It should go away now if you leave your technique alone, If I assume right.

Also, 309l filler metal is for disimilar metals like MS to SS. It works great on SS to SS aswell. Its just more useful, a bit more expensive, but it serves more then one purpose compared to a 308 filler rod.


Hope that helps a bit more

DMH Fabrication

iTrader: (126)

Looks like it had filler rod but it's not the best picture to tell. 304 should be fine for what you want to do. My turbo headers are 321 but most that I build are 304 or ms and then coated. I would just use 308 filler with the 304 stainless but if you want to spend more money 309 will work also as stated above.

WS6HUMMER

iTrader: (19)

Thanks alot guys, this thread has really paid off for me I am learning so much.

Gonna pick up some 309 because I'm sure @ some point I will have to weld some MS to SS.