Best Solution for Small Exhaust Leaks? Sealant?

[Coastal220]

Hi All,

So I just put a Bosal muffler on my 1970 220, which helped significantly (the other one had rusted all the way through), but it still has a few minor but irritating little exhaust leaks.

I can feel small puffs of air coming out of most pipe connections around the clamps--most are so rusted that I'm afraid to tighten or adjust them in fear of making the problem worse.

Does anyone have experience using exhaust sealant, or is this just a total waste of money? is this the best solution next to having the pipes welded? Also, most of the pipes are so old, I'm not sure a muffler shop would even weld it for me... Thoughts?

THANKS!

[Tomguy]

Sealant is a waste of time and money. It will not last. Period. I've NEVER seen it last. Your best bet is to hope the pipes aren't too bad to get welded, if you can't clamp them better (and often times they leak at the clamps on new pipes anyway).

[Carpenterman]

Tomguy is on the money. An exhaust repair that works has been a holy grail for me, as well.

[Coastal220]

Yeah, that's what I suspected. What should I expect to be charged by a dedicated muffler shop to weld several joints? Do they normally need to remove the pipes from the car, or do they have a creative way of working around the top of the pipe near the bottom of the vehicle?

[Mark Rapier]

It is totally ghetto but it works pretty well for any joint or leak not too close to the exhaust manifold, VHT Silicone. Not the brand VHT but the type, it can be found at hardware store that carry stuff for wood or coal burning stoves. The stuff I've used is red comes in a 10 oz tube for about 10-12 dollars.

Once you figure out where the leak is, wire brush the area and an inch or two surrounding it, wet the area with water either a spray bottle or a soaking sponge or rag, goop some silicone on the actual leak and push some into the opening so it forms a kind of plug, then add some more silicone to form a layer about 1/4" - 3/8" thick covering the leak and the surrounding inch or two in all directions. It will take at least 10-12 hours to fully cure and if you can let it sit for a day, even better.

It will hold pretty well and because it's the VHT it will take almost 1000 F degrees. It is a good temporary patch until you either do it right or more rust developes and the pipe's continue to fall apart. But most likely the silicone patch will still be there when you replace the whole pipe. I've even reinforced the silicone with a piece of fiberglass mesh drywall tape for extra strength, but that probably was overkill the cured silicone is pretty tough stuff.

The gray water based stuff in the toothpast tube or shallow can is just too hard and brittle to stay in place once it's dried.

[meltedpanda]

most muffler shops ( if you can find them) will cut the pipes , weld in new and be done, around here what you are describing, if they do not need to replace a lot of pipe - $25

[Marrs]

Find an old-school muffler shop not a new chain-style franchise and they will likely weld or add patches for very little money, $20-40 I'd say based on my own experiences.

[280EZRider]

Originally Posted by Marrs

Find an old-school muffler shop not a new chain-style franchise and they will likely weld or add patches for very little money, $20-40 I'd say based on my own experiences.

I agree completely, although the price may be higher in the Bay Area.

The difference between a franchise shop and a private shop is that most guys in a private shop actually know how to weld.