is this normal

[cme4pain]

Was painting my bilge and where the paint had warn off the glass I found these cracks in the mufflers. I removed a litle more paint to see what was going on. Cracks are on the inside. Wondering if anyone has seen this before.

Is it possible for me to wrap with new glass and epoxy resin?

[cme4pain]

found these cracks in my mufflers. They are on the inside.. But they have me kind of worried cause they are below the waterline.

Can I reglass the outside of these?? I have some 24oz glass and a gallon of epoxy resin left over from a previous project.

This, obviously are cracks related to stress. Not to chemical (alcohol) or wearing issues.
You should first find the source of the issue before deciding on a solution.

A bit more info on the installation would make it easier to narrow the prob!? Please provide.
Regards
Richard

[Landlubber]

Yes Apex, they are stress cracks, and the resin looks very wet too, may I suggest that they are in fact because the resin was so rich that the fractures occurred. I would wrap them up again in more glass as you suggest yourself. Once the pipes ate wet from the exhaust they do not get very hot at all in fact you can actually use PVC pipes for templates, and some have even just left the PVC inside anyhow, with no apparent bad results.

That is why I would just rewrap them with a few ozs and not be too worried about them.

[cme4pain]

As far as the install, the mufflers are in a shamrock cc. I have corrugated hose from the exhaust manifolds for about 3 feet then the mufflers connect to the thru hulls with a coupling. Mufflers are strapped to the stringers.

So there is no flammability issue by re wrapping with glass? I understand they only get as hot as what is going through them. Flammability was my only concern as far as rewrapping. I think the 24oz glass I haveleft will pretty much make them bulletproof.

[Landlubber]

as they are wet exhausts, there would only be a problem if the water pump failed, that would be a serious issue, but it would be anyhow.

You can install a simple temp sender on the pipes if you so wish, make it trigger an alarm buzzer, or better still put a temp on the water injection point, it will be hot very fast without the cooling and may save the day

[Boston]

Originally Posted by Landlubber

Yes Apex, they are stress cracks, and the resin looks very wet too, may I suggest that they are in fact because the resin was so rich that the fractures occurred. I would wrap them up again in more glass as you suggest yourself. Once the pipes ate wet from the exhaust they do not get very hot at all in fact you can actually use PVC pipes for templates, and some have even just left the PVC inside anyhow, with no apparent bad results.

That is why I would just rewrap them with a few ozs and not be too worried about them.

Masali had some experience with pvc pipes in his exhaust system, said they did fine if I remember, but Ild recommend asking him how it went and what if any troubles he had

just a thought
B

[gonzo]

PVC is not rated to the temperature for and exhaust application. It works only as long as it doesn't run dry for any period of time.
Have you seen the cracks before? The pattern is typical of a crushed pipe. That is someone stepping on it.
Epoxy is not the right resin for it. High temperature/fire resistant polyester is the correct material. If you can't get it, use the standard polyester. It is going to cause a problem with the rubber hoses because you'll increase the diameter. At the end, new pipes may be the best.

[cme4pain]

There is reducers on each end already. I would only be reglassing the center section. Tubes are 4 inch and reduce to 3. As far as stepping on its impossible. Tubes are below decks in the bilge and off to the side and hatch is bolted down in this area. Tubes are kind of cheezy too. They sound like they are about 1/16" thick. Where can I get the fire resistant resin?

[gonzo]

Most fiberglass suppliers carry it. It is a requirement on passenger boat enginerooms. Are you sure they were not cracked before?

[cme4pain]

Couldnt Say. They were painted when purchased new. But if you run you hand over them you can feel a slight depression at every crack. No way they came from the manufacturer like that.

[gonzo]

They could've been cracked a long time ago

[SamSam]

Originally Posted by cme4pain

found these cracks in my mufflers. They are on the inside.. But they have me kind of worried cause they are below the waterline.

Can I reglass the outside of these?? I have some 24oz glass and a gallon of epoxy resin left over from a previous project.

You could rotate the one to where it's supposed to be (This side up) (they have baffles) take some pictures and send them to the factory along with a note saying you're posting this all over the internet asking if this is normal for this brand of muffler. Maybe they'll send you some brand new crappy mufflers.

[gonzo]

SamSam: those are not mufflers. Check the facts before calling anything crappy.

[cme4pain]

yes they are mufflers.