Modern Vespa

Where's the post about filling the exhaust with water and freezing it to fix the dents?

This discussion starts here and runs for a bit.

Thanks! My search query I guess did t use the proper words! Did you plug both sides?

I didn't plug either side. I just put some ice cubes in both sides to make sure the ends froze first and directed the expansion into the dent.

It's definitely a trial-and-error thing. I had a tiny split in one of the seams I had to weld up, too, to that's a real risk as well.

It's so easy to bang up an exhaust when running on 8's. I hope it works out for you.

Tried freezing it twice now. I'm not sure if I see a difference.

I probably need a new pipe yea?

Are you sure you're getting all the air out of there before you freeze it?

Absolutely.

No. I'm amazed at how much water this thing holds! I'm trying one more time. I thought I had it filled up this time but no ice clinbef out of the one open end which should have happened if it was full.

Like truly shocked at the amount of water it holds.

Postively Yes.

You only need to fill and attempt to plug the U part of the exhaust and set it upright in the freezer. Try filling the U part with water up to the joints circled in red, then try packing both U openings with ice.

I'm with Ray. If next freeze attempt doesn't work, Bin it and get a new one.

Alright today's the day. Filled the neck with ice cubes then filled with water. Lots and lots of water.

Waited till it poured out of the other end. Then added more again. Looked and saw the water level was right below the spigot. We shall see.

I had the advantage of a separate manifold, so I had easy access to both ends.

In any case, I'm pretty certain that getting the ends to freeze first made a difference for me, forcing the water in the bend/dent to expand into the dent rather than up the pipe.