Muffler repair Q

Nothing added - white is just where I sanded as prep.
Guess I'll have to go buy a 6 pack of cans now :)
Thx
Ron

Pretty sure it's not 304 since I got it at Autozone cheap. It is exhaust tube so assume aluminized steel, but good point that it will likely eventually rust.
Anyways, here's where I'm at currently.
Thanks
Ron

Any issues leaving it in other than the slightly reduced diameter? Would feel better with some metal in there to resist the clamps...
Thanks
Ron

Finally in last stages of spring tune up and last thing to do is tackle muffler repair. After trying to sand/grind delam, found out it was pretty much fried - breaking apart and with gaps. So I cut the tube off and left about 1" that was good to bond to. Plan is to put a metal pipe to act as a mandrel and build up glass around that. Leaving metal pipe in for extra strength and so this doesn't happen again in the future. Went to autozone and picked up a 2.5" ID exhaust pipe which measures 2 3/8" ID, but original ID of glass tube was 2 5/8. Think I'm being anal, but will 1/4" difference make a difference in backpressure that might affect performance? Will post pics soon.
Thanks
Ron

Ron, you don't have to remove the tube to fix this. Repair the original one. It's not that bad and can be fixed. You want to use a thin satin or biaxel weave cloth as it will be able to conform to the complex curves of the muffler. Thicker cloth tends to lift up easier.

Cut out a section of a used juice can, coffee can, large vege can, or metal duct work to use as a form. Before you insert it into the tube place a sheet of wax paper between it and the wall so it won't stick to it. If the flange is weak and damaged then add a little resin to the damage before inserting your "backup form"

I'm gonna disagree with my fellow CCFans and say you don't have to grind out the delaminated plies until you hit solid. We do this sucessfully where I work by doing the following....

Prep the ouside wall of the damage my sanding it lightly, removing the black paint, then wipe it down with acetone to be sure it is free from all oils before you start. Mix up your resin then set it aside. Heat up the damaged area with a hairdryer and get it as hot as you can. Doing this will enable the damaged plies to wick up the resin and will flow deep into the damage getting better penetration and a more solid repair. Then start brushing in you resin being sure you soak it in everywhere.

Once you have thouroughly soaked the cloth with resin, use packing tape (clear or brown tape) and wrap the tube with it pulling it as taught as you can to compress the delaminated layers against each other. ( hince reinforcing the inside with a metal sleeve) Wrap it up as tight as you can being sure you fully encapsulate the entire damaged area. Once it cures remove the tape and lightly sand the tube. Coat the tube with resin then add a couple of repair plys going totally around the tube. Start and stop your repair plies in different areas so that you won't have a concentrated weak point at the seams. You'll want to overlap each ply about 1/4 of an inch. At this point leave the form in the tube and rebuild the flange damage if you need too.

I'd wrap it at least twice then cure it. Lightly sand it then paint it and reinstall.

Let us know how it goes and post pic's of your repair so others can learn. Good Luck!

Ron - I did a similar repair on my invertaflow. I just used some generic cloth I got at wallys. I would not cut the tube off. I recommend just grinding the delaminated part back until you get to solid material & tapering it out to a very shallow angle. Using a cylinder of some sort as a ID form is a great idea. After you get it built up, just sand it back to the correct OD.

Use epoxy resin, of course.

The whole boat thing is definitely a major hobby - it is good that I store it offsite 8 months of the year so I focus on other things too!