JB Weld---reinforced fiberglas

killarney_sailor · #1 (**permalink**) 11-13-2011

Without getting into too much detail, a few months ago when we were approaching Moreton Bay in Oz, we fired up the diesel after a nice 9 day passage when it was not used and the nipple that joins the engine to the exhaust elbow had broken off. We did a repair to it rather than calling someone for a tow (we had to go along a very narrow, twisty ship channel in the dark so sailing was not going to happen.

Anyway, what I did was temporarily position the broken nipple with a couple of wires and then put a good coating of JB Weld (some sort of epoxy with metal filler) on it, then put a piece of West Systems fibreglass tape on/into it and then another layer of JB Weld on top. We had to motor for about 12 hours to the Customs/Immigration dock up the Brisbane River (don't get me started on that one) and then to the marina where we are now tied up. The repair looks the same as when except it has changed color. I have a new nipple (brought back from Canada to get the thread right) but I look at the repair and it seems a shame to take it all apart and it might be difficult to get the broken piece out of the elbow - and I don't really want to buy a new one since this one is ok and they are pricey.

Am I asking for trouble if I trust the repair? I know they make exhaust fittings out of FG and this one has a higher quality binding agent.

Capt Len · #2 (**permalink**) 11-13-2011

Doing it right! I'll bet you know the answer Question is Why did it break what tools do you need to get the stub out and do you have spare nipples. If this has hot salt water flowing thru even ss wont last forever. Probably need a butane torch, easy out and neversieze. Goodluck.

killarney_sailor · #3 (**permalink**) 11-14-2011

I think it just rusted through but did not look any different than when I bought the boat four years ago. The stub could be a real issue since it broke off almost flush with the surface of the exhaust coupling. I have a replacement nipple and we are not going anywhere until the end of cyclone season so Aprilisih. I think I might have a go at it in the next couple of weeks and then I can take it back to Canada when I go for Christmas. At least the machine shops there will be familiar with the thread - they use metric or some British standard thread here.

jrd22 · #4 (**permalink**) 11-14-2011

I've used JB for a lot of repairs, it's great stuff. Whether it will hold up in that application I couldn't say but I would worry too much about it letting go at a critical moment so I think I would try to replace it now while you have time to mess with it.

PaulfromNWOnt · #5 (**permalink**) 11-14-2011

I'd say take the easiest route. Is it easier to repair where you are, or in a seaway with swells/waves to contend with.

Parts never ever fail at convenient times.

SloopJonB · #6 (**permalink**) 11-14-2011

Quote:

Originally Posted by jrd22

I've used JB for a lot of repairs, it's great stuff. Whether it will hold up in that application I couldn't say but I would worry too much about it letting go at a critical moment so I think I would try to replace it now while you have time to mess with it.

Exactly - think about when it WILL fail - exactly when you need it since it won't fail when you are under sail.

Fix it in comfort, ESPECIALLY since you anticipate it will be a difficult job.

Cherie320 · #7 (**permalink**) 11-14-2011

JB weld is a great product and it has bought us time on numerous occasions (industrial repair applications). But I never slept well until the job was completed correctly with new material. It's a patch, not a fix. Fair Winds - Pat

BarryL · #8 (**permalink**) 11-16-2011

Hey,

A few years ago I was in a sort of similar position. I brought my boat to the dock to load with gear before we left on a week vacation. At the dock I opened a lazarette to get the water hose and I smelled exhaust gas in the engine compartment. Long story short, the exhaust riser has rotted out. I could not get a replacement in time to start the trip. So I made a short trip to an automotive repair place and bought a few supplies. JB Weld and some metal braces worked and allowed me to run the engine for about 20 hours on that trip, including trips up and down the NY East River, both with and against the tide.

But, as soon as I got back to my home port I had a new part installed.

It's up to you, but I would change out the temp repair as soon as it is convenient to do so. You don't want to be out at sea trying to fix the fix.

Barry