Any tips for welding something you can't see?

Are you sure you are not a weldment designer in your day job. It really helps if you can remove, weld , then reinstall. At least see if you can drop the pipe down off its hangers onto some temporary wire ties. If it is stick you can actually bend the rods. Some people don't know that. If you can sit a pocket mirror in the right place it helps. the mirror trick will not likely work overhead. Some mig nozzles are more bendable than others. If you have spare parts you can bend a custom gooseneck. Worst case is to cut a big hole in the bottom part of the pipe then weld up the upper section from the inside. After welding that up make a patch to cover the hole on the underside. Randy

The R&R option would turn a 10 minute job into a 3-4 hour job. I'm trying to repair the Y-pipe on my '79 GMC 4x4, and removing it requires removing the front driveshaft and the rest of the entire exhaust system. I've actually gotten it pretty much done, there's just a small section at the very top that I couldn't get (MIG gun was hitting the bottom of the torque converter), and it's going to have to stay that way 'till I get my headers on.

Thanks!

Jeremy

I made up a mirror out of a 3x5 gold mirrorized filter with a plastic cover lens to eliminate the pitting associated with glass. Then bend some 3/32 6011, set welder at straight polarity, turn it down, and think "backwards"

Except bending some 3/32 6011 won't do me any good with my MIG gun...... ;-)

Is there any chance you could reach the spot with a small oxyacetylene torch?

JC> The R&R option would turn a 10 minute job into a 3-4 hour job. I'm trying JC> to repair the Y-pipe on my '79 GMC 4x4, and removing it requires removing JC> the front driveshaft and the rest of the entire exhaust system. I've JC> actually gotten it pretty much done, there's just a small section at the JC> very top that I couldn't get (MIG gun was hitting the bottom of the torque JC> converter), and it's going to have to stay that way 'till I get my headers JC> on.

JC> Thanks!

JC> Jeremy

If you want to keep it down to a 10 minute job why dont you plug the remaining small section at the top with muffler gum?

ive used it and it holds good in high pressure ares. fixed a 1 inch gash which was 2 feet away from where the exhaust manifold mates to the block.

will take you 5 min. if it ever blows you can always revert to the full blown job.

the other idea i thought of was to wrap some thin sheet metal around this pipe and weld where the ends meet at the bottom where you can see. the metal will cover the exposed hole at the top.if the pipe here is not completely clyindrical you might want to add some muffler gum as a sealer.

Sam

dare I post " JB Weld" to seal the rest

I don't know what a slip flange is. I'm imagining a piece of larger tube cut in half to fit over the break. Can you describe it?

Oh I get it. He has to cut the pipe in two to install & weld it. Pretty snazzy if he can flex the cut pipe. :^) With that thought, he could just buy two flanges and a gasket, cut the pipe, flex/muscle it into position for welding and then bolt it together. That would be my choice since I don't have stock that size to fabricate from, don't have the cutting skills(tools) to make it other than making it a half day job on the flange alone. If the pipe won't flex, he will be SOL since he probably won't know till it's cut in two.