Water lift muffler repair

[IH82BL8]

The muffler on my boat consists of a recessed compartment in the hull liner, a flat lid sealed on top of the compartment and two pipes for exhaust hoses. The lid was leaking, so I'm repairing it. Once I got into the project I realized it had been repaired once before by someone who shouldn't make repairs. So I'm making a new lid for it and I need to epoxy the two pipes through the new lid. I have a few questions. Will thickened epoxy bond to PVC or do I need to use whatever pipe material was used in the original? The original pipes look like fiberglass. Does anyone know where I can buy this stuff or do I have to salvage and reuse the original pipes?

Thanks.

 

[woodster]

The muffler on my boat consists of a recessed compartment in the hull liner, a flat lid sealed on top of the compartment and two pipes for exhaust hoses. The lid was leaking, so I'm repairing it. Once I got into the project I realized it had been repaired once before by someone who shouldn't make repairs. So I'm making a new lid for it and I need to epoxy the two pipes through the new lid. I have a few questions. Will thickened epoxy bond to PVC or do I need to use whatever pipe material was used in the original? The original pipes look like fiberglass. Does anyone know where I can buy this stuff or do I have to salvage and reuse the original pipes?

Thanks.

why can't you salvage the pipes you have i assume you have a way to sand and grind the material ...or you can do a search on the net and find fg tubes for sale i think centex sells the tubes and replace them ...i will tell you that polyester resin will stand the heat better than epoxy ..and you also can thicken it with the micro fibers or cabosil

 

[CloudDiver]

Its hard to make recommendations about repairs when not familiar with your specific boat and how your wet exhaust is constructed and no pictures... (not picking on you, just sayin), BUT;
Yes, epoxy will stick to PVC. When gluing PVC material to the transom of an inflatable boat, WEST system G-10 epoxy is recommended. This is a good product because it is pre-thickened, and if you don't need a large amount you are not having to buy it by the quart or gallon.
With that said, I hope you are not planning to use PVC plumbing grade pipe in the place of fiberglass tube? Not a good idea in a wet exhaust application. Your exhaust tubing should be marine rated wet exhaust hose like SHIELDS series 250 or Trident in rubber or silicone.
I am assuming the fiberglass tubing you are talking about is only what enters and exits the box, cut a short length to make a flange where the appropriate wet exhaust tube will be clamped? A good source for fiberglass tube in short lengths at a competitive price is Goodwinds.com

Epoxy is better than Polyester resin, hands down. Temp should not be an issue, the point of a wet exhaust is to reduce temps in the exhaust system. Polyester resin does not have a very good secondary bond strength when repairs are done on previously cured polyester resin. You would be correct in doing your repairs with epoxy.

I hope this helps... without pictures of the system and the damage that needs repair it is just my best guess based on the info provided.

 

[IH82BL8]

Woodster, I considered salvaging the old tubes as a last resort. If I buy new tubes I can save myself a ton of work have a neater finished product.

I think I'm going to buy from these guys: http://www.mgs4u.com/fiberglass-tube-rod.htm

CloudDiver, these tubes are installed in the lid of the muffler to attach exhaust hoses to. The remainder of the "piping" is flexible exhaust hoses. See attachment. I didn't include clamps in the sketch, but the hoses will be double clamped.

 

[woodster]

Woodster, I considered salvaging the old tubes as a last resort. If I buy new tubes I can save myself a ton of work have a neater finished product.

I think I'm going to buy from these guys: http://www.mgs4u.com/fiberglass-tube-rod.htm

CloudDiver, these tubes are installed in the lid of the muffler to attach exhaust hoses to. The remainder of the "piping" is flexible exhaust hoses. See attachment. I didn't include clamps in the sketch, but the hoses will be double clamped.

wow thats close to home here only about 45 miles or so good find

 

[CloudDiver]

Looks good, just make sure the tubes they sell are made with epoxy, not polyester or vinyl-ester resins. I don't know if you checked out Goodwinds, but I know that they only use epoxy in their tubes. The site you provided looks good at reasonable prices with good selection of sizes/shapes, but their shipping prices are nuts!
Just be sure to get the correct wall thickness, you want those tubes strong so they don't collapse under the clamping force of the double hose clamps.
After you epoxy the new tubes into the lid, I'd suggest a few layers of fiberglass tape on both sides at the union. Also, with the water muffler drained, I'd sand the whole thing out and let it dry for several days with a dehumidifier in there, really dry that box out... Clean with acetone several times during the process. The apply 2 barrier coats of epoxy, this will make it really 'water-proof', because polyester resin actually is not (at a microscopic level).

Woodster, I considered salvaging the old tubes as a last resort. If I buy new tubes I can save myself a ton of work have a neater finished product.

I think I'm going to buy from these guys: http://www.mgs4u.com/fiberglass-tube-rod.htm

CloudDiver, these tubes are installed in the lid of the muffler to attach exhaust hoses to. The remainder of the "piping" is flexible exhaust hoses. See attachment. I didn't include clamps in the sketch, but the hoses will be double clamped.