Repairing FRP Exhaust "Wye", Advice Needed

[Montenido]

Hi folks,

My boat has two 5" diameter FRP 2-into-1 wyes that are for the wet exhaust on each engine (Cat 3208 NA). One of them has a small crack that drips saltwater. Can I repair this with epoxy, or should I use some type of high temperature resin? I think that I can do it from the inside of the wye, and then finish it on the outside. Has anybody done a repair like this?

Thanks for any tips.

Cheers, Bill

 

[DavidM]

Bill:


I would do this just like any other fiberglass repair. Grind the crack out and taper it back an inch or two. Then lay up glass and resin over the crack. You can use epoxy or polyester resin. Epoxy sticks better in a repair situation.


Epoxy alone will soon crack again.


David

 

[caltexflanc]

You need a high temperature rated resin. Recommend you contact one of the exhaust specialists like MESA or D'Angelo and they can hook you up with the right product. This is a system that can sink or burn down your boat.

 

[Montenido]

Thanks for the replies. I think I might try JB Weld high temperature epoxy putty to begin with. The crack is just hairline and not structural. Has anybody used this before? If this doesn't work, I'll do it the proper way.

Cheers, Bill

 

[jleonard]

I personally wouldn't do a temporary that might work repair. May as well fiberglass it and be done. If the repair is on the outside of a wet exhaust
There must be a supplier in your area that can recommend the right resin.
Or there are internet sources as well.
I use LBI (Legnos Boat Inc) out of Groton, Ct because they are local to me.
There might be info on their website or give them a call.

 

[C lectric]

YOur choice but consider that if you simply cover it up, which is likely what you are going to do, that the next time the crack appears it will be bigger as it will grow. Do it right now and you won;t be redoing later.
If it comes back it may not do it at a convenient time.

Caltexflanc has a serious point.


If you go with the JB then at least use a couple layers of 6 oz cloth in the repair , working the JB right in like you would with any resin.

Also take a good look at the support. Maybe the exhaust hose is hanging from the wye which is what started the crack. Pieces like this are not meant to be structural. Do a good repair and check the support. Add a hanger or two to take any load/weight off.

 

[Montenido]

You guys are right - fix it correctly the first time. I will get some high temp epoxy and do it right.

Cheers, Bill

 

[bayview]

Figure out why it cracked first. Those things should not be under stress.

 

[what_barnacles]

You guys are right - fix it correctly the first time.

That would be with a new Y.

 

[Shoalwaters]

I would do this just like any other fiberglass repair. Grind the crack out and taper it back an inch or two. Then lay up glass and resin over the crack. You can use epoxy or polyester resin. Epoxy sticks better in a repair situation. Epoxy alone will soon crack again.

I agree, this is the right way to do it. No special hi-temp resins required as the raw-water/exhaust mix that passes through this fitting is no hotter than bath water. I would use epoxy resin though - it is a much better adhesive than ordinary polyester resin. I suggest washing the surfaces with acetone after grinding and before applying the mat and resin. This will avoid those little fish-eye shapes in the resin caused by residual grease or oil.

 

[Capt.Bill11]

I agree, this is the right way to do it. No special hi-temp resins required as the raw-water/exhaust mix that passes through this fitting is no hotter than bath water.

FYI, if the water flow becomes restricted, or cuts out completely, the exhaust gases are no longer at "bath water" temperature.

At the very least he should use the high temp JB Weld.

 

[what_barnacles]

LOL stop it. Do not repair the Y, replace it.

Youre talking about something that can flood your engine room and possibly sink your boat. Think not? What about getting caught in a storm and the same forces that cracked it the first time reappear, and your glued to the instruments and outside the windshield. You'll never know it's flooding your bilge until you have way too much in there.

 

[kulas44]

I guess I dont understand why a person would want to replace a piece of equipment that is easily repairable, and expensive. Personally, I would probably remove it and clean it up really good, then wrap it with 3 or 4 layers of "glass cloth and a good 4 to epoxy. If the crack is accessible I mite repair it in place, as long as I could still completely wrap the area with epoxy/"glass cloth. You can get 'glass "tape" in whatever width and weight needed. This is all just basic fiberglass repair, not rocket science.

 

[MICH MIKE]

If you do the temporary repair while waiting for the new part, I would suggest 'stop drilling' small holes at the ends of the crack before applying the bandaid.

 

[Capt.Bill11]

LOL stop it. Do not repair the Y, replace it.

Youre talking about something that can flood your engine room and possibly sink your boat. Think not? What about getting caught in a storm and the same forces that cracked it the first time reappear, and your glued to the instruments and outside the windshield. You'll never know it's flooding your bilge until you have way too much in there.

That's why you should have a high water alarm.

It sounds like a simple repairable crack to me. I mean you don't buy a new boat if you crack the hull.

 

[Scary]

Repair it

Grind out cracks 15 to 1. Add chopped fiberglas to your choice of resin. If you chose epoxy most mats are not compatible with epoxy resin. The binders will not wetout. If you can wrap the crack with fabric that will add strength. Jb weld has its uses , this probably not my choice for this repair.

 

[caltexflanc]

No special hi-temp resins required as the raw-water/exhaust mix that passes through this fitting is no hotter than bath water

I'd invite you to stick a temp probe in there sometime, since sticking your hand in there isn't possible. Now true, the place where it is leaking is "water cooled" ... water that has been through various heat exchangers and is now in contact with exhaust gasses. But you will want to thoroughly seal the area around the crack as well. Not having seen the suspect crack, I don't know how big the crack is or what its root causes may be (an important point raised by other posters). I certainly would want a professional opinion, rather than merely rely on us internet cowboys with no first hand view of or vested interest in the problem or the outcome of the fix.

 

[Montenido]

Hi folks,

Thanks for the lively answers, here is a bit more information. It is a hairline crack with some salt residue leaking out, nothing structural. Chances are it has been this way for quite some time. The crack is accessible, and on the bottom of the wye, so water probably normally flows over this area. I have very good fiberglassing skills, as I have been making repairs since I was a teenager (a LONG time ago, lol). I do have a high-water alarm. The leak is virtually dry under operation, I just want to fix it as the boat is new to me. I have ordered some high temperature epoxy that will certainly do the trick.

Once again, thank you all for your input.

Cheers, Bill

 

[sunchaser]

I'd be concerned about aging FRP parts going through rigorous heating and cooling cycles with resultant brittleness.

My 2 Ceteks showed a few salt crusts since new that have been successfully covered by JB. Only when vessel running with no signs of moisture at rest. Cetek says not uncommon.

But if a crack showed up I'd replace them in a heartbeat. Not because I'd worry about the boat sinking though, just all that sooty exhaust in the ER.

In many vessels regular and thorough checks occur while underway - roomy ER advantage so little things can be monitored. If OP's vessel is a hatch lifter and this elbow not easy to routinely observe, I'd consider replacement.