MS Pilot 34 - Exhaust Port Cracking

[aviator7836]

We have recently purchased a 2005 Mainship Pilot 34 Rumrunner II that is overall in excellent condition. One major discrepancy though is the presence of some significant cracking of the gel coat and possibly fiberglass matting around the exhaust port. The cracks are a few inches long and radiate out on the outer hull from the exhaust port. Clearly this is damage to the gel coat and/or glass layup from heat.

Has anyone else experienced this and do you have any experience with repairing the cracks? We are about to have a fiberglass specialist grind down the area and repair it but would love to hear any experience and advice from others who might have had a similar problem.

Thank you in advance!

Doug

 

[Comodave]

By the time the exhaust gases get to there they shouldn’t be hot enough to do any damage. I would check the exhaust route carefully to see what condition the hose is in. If it has been hot enough to damage the fiberglass then the hose should have melted too. Most likely Mainship didn’t make the glass thick enough there and it is just stress cracking. Before you spend the money to repair it, maybe you need to lay in some more glass on the inside to give it some support. Otherwise the repairs may crack again…

 

[rgano]

By the time the exhaust gases get to there they shouldn’t be hot enough to do any damage. I would check the exhaust route carefully to see what condition the hose is in. If it has been hot enough to damage the fiberglass then the hose should have melted too. Most likely Mainship didn’t make the glass thick enough there and it is just stress cracking. Before you spend the money to repair it, maybe you need to lay in some more glass on the inside to give it some support. Otherwise the repairs may crack again…

Nothing like that on my 2005 30 Pilot II, and agree that it is likely surface only stress cracking of the gelcoat.

 

[DrissZougari]

In my opinion, Stress cracking will be visible all around the exhaust port.
Having said that, the exhaust port is located on the starboard side of the boat and all the cracking is on the trailing side of the port means you have some kind of heat issue there (water & hot exhaust hitting the trailing side)
You should check all your hoses and possibly check your temperature using an IR temp meter (after a long cruise at speed).
They may have fixed any overheating issues before the purchase, but it is worth doing.
Congrats on your purchase and welcome to the group.