Weld New Pipe to Old Tailpipe Flange: Damage Gasket?

[Vanagon Nut]

Hi folks.

"2.1" Muffler is ok, tail pipe has rust perforation at flange, tailpipe bolts rusted in place, my Dremel just died. Instead of snapping of bolt heads, drilling out remains.....

Will MIG welding, maybe stitch welding, a new piece of pipe to flange burn off the gasket causing a leak?

I can't recall if I used a paper gasket at tailpipe or the metal type.

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[MarkWard]

Stitch welding with your mig should be fine. Move around the pipe to keep from
overheating one area.
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[Vanagon Nut]

Thanks Mark.

If I end up damaging gasket, maybe heat will loosen up the bolt threads. I may even drop the muffler for the job. We'll see. With 2 Vanagons and only 1 shop bay, I'm trying to find ways to reduce downtime though a tail pipe hardly qualifies for that.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[MarkWard]

Isn’t the tailpipe through bolted? With all you do, might be time for a small acetalyne torch set. You could burn those off in the time it takes to post a question. HD has a complete set for $300. You won’t believe the uses you can find for it. I imagine Harbor Freight and Northern Tool have something similar
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[Vanagon Nut]

The tail pipe is bolted on as it came from factory so not through bolted.

I'd love to get set up with more tools. Just not sure how long I'll be renting here. But if this is the set you refer to:

https://www.harborfreight.com/portable-torch-kit-with-oxygen-and-acetylene-tanks-65818.html

doesn't look too big. e.g. 20 cu ft tank is about 15" long?

https://www.amazon.com/Steel-Oxygen-Cylinder-CGA540-Valve/dp/B01E2TS1TQ

Never tried oxy acetylene "hot wrench" on stuck fasteners. I hear it works great.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[MarkWard]

That’s a very similar kit. You can also weld and braze with it. Working on old vehicles it’s a must have. That’s portable enough you can do stuff for your friends and earn beer money.

I know the air cooled tailpipe bolted directly to the muffler, but would have sworn the water cooled was through bolted. Anyhow, don’t worry about your gasket.
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[Jake de Villiers]

[danfromsyr]

for fine detail and close quarters work I use a set of these 'brazing' torches for a hot wrench. (I do have a BIG tank set too).
the Oxy bottle usually gets several nuts/bolts. though you want to be quick/dilligent it's not the most efficient hot wrench but it has it's places and is great for that incidental use like you are experiencing.. without the full $$ commitment. plus it's not usually considered 'torches' if a land lord or insurance person ever inquires.. it's a plumbing tool

[bluebus86]

[MarkWard]

We carry a portable setup similar to the one Neil linked to the race track for emergency repairs. No you won’t run a production shop with it, for the DIY guy that gets in jams from time to time, it’s plenty adequate and has a small foot print. Add a rosebud tip and a #1 tip you can get a lot accomplished.
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[bluebus86]

[Vanagon Nut]

Thanks for all the great information here folks!

We'll see. It's been sunny lately so I've been "Vanagon Lazy" about preemptive work and maintenance but the tail pipe will need to be done before summer I'd guess. The bigger looming job is the clutch housing and maybe engine crank seal but they can wait as well.

The MAPP/O2 set up looks tempting even just for the brazing capability, of which I've found the need for from time to time.

I'll check out HF during my next trip south but Princess Auto up here in Canada (similar to HF) has a similar looking foxy acetylene. The description re: tanks is interesting, maybe for legal reasons ? but there is a smaller and larger tank most likely for O2 and acetylene.

Princess Auto:

https://www.princessauto.com/en/detail/oxyfuel-cutting-and-welding-tote-with-tanks/A-p8590465e

But after CAD to USD conversion, it's still priced higher.

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Vanagon Nut]

[Vanagon Nut]

So the answer is basically "no". In spite of not allowing a whole lot of time between stitch welds, the gasket still seems fine.

A scrap of new 2" aluminized pipe fit ok as-was but I used a ball peen to reduce OD at one end a little to match it to the old tail pipe OD.

I took time to grind off as much rust as possible and was able to leave ~ 3/16" of the old tail pipe at flange which helped; in part, the welds contacted that material. The welds look horrible (MIG wire feed seemed uneven, sporadic. I should've run a practice bead first) but hitting the pipe hard several times with a dead blow hammer didn't knock it loose.

A jack stand and a weldors magnet held the work in place for tack welds.

The muffler sits lower than the OE WBX position so i think this job would be harder with the muffler at OE position.

Pic:

https://lh3.googleusercontent.com/pw/ACtC-3fOU0Mdq...authuser=0

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[4Gears4Tires]

My previous MIG welder was certainly on the cheaper side and it had terrible feed issues. A friend solved it by opening the case and using a clamp on the wire feed wheel housing. That dramatically improved the quality of the welder. Took it from a $125 welder to at least a $200 welder!
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'87 Syncro
Ferric Oxyhydroxide Superleggera Edition

[Vanagon Nut]

[4Gears4Tires]

Yep, exactly. I've also read of people adding small fat rubber bands (like the ones from the grocery store for veggies) around the feed wheel to improve grip.
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'87 Syncro
Ferric Oxyhydroxide Superleggera Edition