TIG welding experts, advice wanted

[CCjon]

I have a 2002 1150GS Adventure. A side seam on the catalytic converter has opened up about 1 1/2 inches long. I could ignore it but after several hours of riding, the hot gas blowing on my left heel is bothersome.

Talked to an aircraft welder who says he can TIG weld it if we lay the bike on its side. When I said something about removing the gas tank to disconnect the battery to protect the computer, he says he would clamp the ground(?) wire to the cat near where welding and there should be no problem. Says it would be a short loop with little if any current going thru the bike.

What do you say? Would you TIG weld your Cat this way?

Thanks for your opinions. Always valuable on this site.

CCjon


PS Inmates, before you tell me to dump the Cat and get a Y pipe, I tried that. Got too much vibration in the handlebars so went back to the Cat.

[mouthfulloflake]

should be doable, as long as no oil or nastyness on the inside of the busted seam, ubless the heat cycling over time has made that stainless fatigued.

for sure disconnect the electronics though, the TIG welder most likely has a HIgh frequency arc starter. Typically they wont hurt anything, but it would suck it fried some non-robust component inside the brain box.

[hasenwerk]

Originally Posted by mouthfulloflake

should be doable, as long as no oil or nastyness on the inside of the busted seam, ubless the heat cycling over time has made that stainless fatigued.

for sure disconnect the electronics though, the TIG welder most likely has a HIgh frequency arc starter. Typically they wont hurt anything, but it would suck it fried some non-robust component inside the brain box.

+1 on that - takes a minute to disconnect the negative terminal on the battery.

[RMR]

I agree with the previous post. most decent welders have a HF starting circuit to help establish the arc. Personally, I would remove the cat entirely before welding on it, as disconnecting all the electrics seems to be a bit of a bother.

the only other item that comes to mind, would be to match the filler material to the exact type of stainless used in the cat. I don't know where to start finding that out though...

[JurgenB]

+1. Take the cat off. That way you may also be able to clamp the cat nicely so that the seam ends match up and you don't have a gap to bridge.
Disconnecting the battery is not enough. Welding stainless may be tricky - may have to experiment. Not sure what exactly the material is, but it's highly heat-resistant.

[BobbySands]

I second the removal of the cat.

1. it's easier than laying a 550 pound bike on its side.

2. it'd be easier than welding it in position. This means less to a skilled TIG welder than your run of the mill welder.

3. Grounding as near to your work as possible is always a good idea, and should, in theory, protect your electronics. But as the Motronic is so expensive and finicky, why risk it?

4. I know a dozen or so good TIG welders. A high-freq machine is only needed for aluminum. Many of them never touch the stuff. But you can always ask. None-- exactly none of the 6 machines we have on the job at this moment are high-freq as we are only welding stainless and carbon.

5. as Jurgen said, if the high freq machine was going to fuck with your electronics, disconnecting the battery is not enough.

do yourself a favour and remove the cat.

6. The repair on stainless should be a snap.

[mouthfulloflake]

we always used HIgh Freq starters doing a286, hastelloy, airplane stuff.

the scratch start contaminated the weld too much to pass Zyglo, and Xray, not to mention hard arcs, and arc " breaking" led to cracks.

BUT, his welder might work at a different type shop, I was just putting it out there.

[sbrownn]

Originally Posted by BobbySands

I second the removal of the cat.

1. it's easier than laying a 550 pound bike on its side.

2. it'd be easier than welding it in position. This means less to a skilled TIG welder than your run of the mill welder.

3. Grounding as near to your work as possible is always a good idea, and should, in theory, protect your electronics. But as the Motronic is so expensive and finicky, why risk it?

4. I know a dozen or so good TIG welders. A high-freq machine is only needed for aluminum. Many of them never touch the stuff. But you can always ask. None-- exactly none of the 6 machines we have on the job at this moment are high-freq as we are only welding stainless and carbon.

5. as Jurgen said, if the high freq machine was going to fuck with your electronics, disconnecting the battery is not enough.

do yourself a favour and remove the cat.

6. The repair on stainless should be a snap.

When I change from welding aluminum to stainless the major change is to go from AC to DC. Most of the other settings do not change at all if the materials are of similar thickness; perhaps reduce the current for stainless.

[jsb223]

Take the cat off...

Find someone with real stainless welding experience.

TIG is not required, a MIG setup with a gas and wire change and
someone with real stainless welding experience can get the job done.

The thinner the material...the more experience they'll need.

That is someone with real stainless welding experience.

[drtlvr]

yes take the cat off,I weld stainless at Burger Boat co,I would use 316L for welding the cat,that will not rust,you can do some major damage to the electronics even if you remove the battery, if I was close to you you I would weld it for you,but I'm leaving tomorrow to deliver a yacht and won't be back for 3 weeks.

[fxstbiluigi]

Ground as close as possible to the weld. Disconnect the Neg. Term. on the Bat.(just to be sure nothing goes thru the $$$$) anyone capable with a TIG should be able to do the job in position.

[rxcrider]

remove the CAT or spend more time disconnecting all electronics. Just disconnecting the battery (both ends) may not be enough. Just ask the digifant (nearly motronic) box out of my dad's VW Vanagon back in the day - it wasn't too fond of him welding a split in the side where a fork lift attacked it.

[CCjon]

Thanks for the input guys.

The consensus is to remove the Cat and weld worry free. That's what I'll do.

With the table lift, removing and re-installing the Cat is easy job.


Many thanks
Ride safe

[G B]

Where I work we repair and sell big truck, when welding on them we disconnecting the battery (both ends) and connect the battery cables together so we do not burn the computers in the Can-Bus system. By using this method we do not have a problem.

[weldpro]

Originally Posted by Adventurrer

When I change from welding aluminum to stainless the major change is to go from AC to DC. Most of the other settings do not change at all if the materials are of similar thickness; perhaps reduce the current for stainless.

You are forgetting about changing the HF from continuous to start only. I am sure this is just an oversight though, and you know this just forgot to omit it!

To the original poster I would have no problems (ABSOLUTELY ZERO!) doing it the way the guy said he would however.......I would charge you more than if you brought it to me as just the part. My real concern would be if gas might leak out (from the gas tank or carbon can) during the job, and I could not see it whilst I was working with my helmet on.

As long as the current is not going through any circuits there will be no problems. The same goes for bearing assemblies as they will arc across if the circuit is through them, and ruin the bearings.

I see in this thread that folks who work for someone else tend to have shop policy's that say they must do this & that blah blah. Well if I had any employee other than myself doing the more complicated work then I would have some sort of "procedure" for an employee that would not share in the liability if they screwed up the job! I have tons of experience with working around electronics (even canbus), and I have yet (knocking on wood) ever had anything go wrong. Having the responsibility to have to repair or replace all those expensive parts is a huge motivator to never not know exactly what I am doing.
Hope this helps,
Richard