Prairie trawler leaking issue

MAP · 06-01-2021, 10:26 AM

Spent the weekend on our new '79 Prairie trawler in massive rainstorm and heavy wind. I have to say, we were cozy! But...both cabins had substantial leaking (very little from the windows, but some), but the side walls up under the overhang around the beds leaked and got the mattresses pretty wet. Everything on the outside of the boat seems very well sealed. Has anyone had this problem and solved it?

**Comodave** · 06-01-2021, 01:40 PM

Not on your particular boat model, but the process is pretty much the same. You need to find the place where it starts coming in. Then look, usually higher but not always, and see what is up there and then start rebedding the items. Sometimes the leak can be below where it enters the boat and the water can build up inside the side of the boat until it spills over into the inside. I would maybe cover a portion with plastic taped securely to the boat. Then spray with a hose and see if the leaks show up. If they do then the leaks are somewhere else. If it doesn’t leak then you have covered the leaks. Keep doing this until you narrow it down, then rebed whatever you suspect. You can use paper towels taped inside to see where the leaks are coming through. The paper towels will show where they get wet. It is a real PITA to find leaks but you must find them and stop the bleeding, so to speak. If the windows have not been bedded recently that is a good place to start. Marinehowto.com has an excellent article on how to bed things. Good luck.

janice142 · 06-02-2021, 03:56 AM

I am not an expert, however on a prairie near me two points of water intrusion were identified and cured.

1. In the anchor locker, wood went bad just aft of the Lofrans.

Resolution. Wood removed from the inside. I contributed teak that was soaked in epoxy and used to reinforce the area.

2. Bow, between raised forward cabin and anchor locker there were soft spots.

Resolution. Two part epoxy mixed with cabosil (spelling??? - the microbeads that do not expand). Holes 1/4" drilled in bow every 6" in a curved pattern. Picture a crescent moon shape semi following the curvature of the bow. Starting at the high point, mixture squirted into holes slowly.

Use a giant syringe. The syringe can be cleaned and reused.

The syringe treatment took about three treatments. The deck is stiff again, with zero soft spots. Water did not get in though we have yet to experience torrential downpours.

Good luck Cap'n. And ask again for the gents to provide better/more in depth instructions. I will no doubt learn more shortly as this is planned for the overhead above my galley where I have soft spots and leaks

Pete Meisinger · 06-02-2021, 06:37 AM

Teak Decks or fiberglass? It makes a difference.

pete

CaptTom · 06-02-2021, 06:53 AM

The Prairies have a double-shell cabin construction, so you'll find the leaks always end up around the edges.

The first place to look is rail stanchion bases and other deck hardware. Re-bed them all if it hasn't been done in the past 5 or so years. I found an assortment of bolts and screws, and some had aluminum backing plates while others didn't. I suspect I wasn't the first one to tackle this problem. I'm down to one leaky stanchion as of the last rainstorm.

The problem is replacing the nuts where you can't reach the other side. My latest attempt was rubber blind nuts, which keep the leaks out pretty well but leave the railings a little bit wobbly. I think I'll find a more robust solution for the ones on either side of the access breaks. Those tend to be used to pull yourself aboard. The rest I'll keep the rubber nuts.

I'm not sure of your experience level, but for future readers, do NOT just slather the outsides of the bases with sealant or adhesive - especially silicone! You have to actually remove and re-bed each one.

MAP · 06-07-2021, 09:30 AM

We have a fiberglass boat.

sailormike · 06-07-2021, 07:40 PM

Quote:

Originally Posted by MAP

Spent the weekend on our new '79 Prairie trawler in massive rainstorm and heavy wind. I have to say, we were cozy! But...both cabins had substantial leaking (very little from the windows, but some), but the side walls up under the overhang around the beds leaked and got the mattresses pretty wet. Everything on the outside of the boat seems very well sealed. Has anyone had this problem and solved it?

On ours we had problems with the stanchions leaking. also the rub rail around the deck seam is a notorious place for leaks. check all seams and mounting areas for leaking. Our windshields last year started leaking again after 20 years they were re sealed with silicone. I cleaned out all the old silicone and old rubber gaskets that were dried out and destroyed from sun. I was able to source the rubber gasket material from Hatteras parts supplier. That compared with new sealant not a leak. The side windows we had leaks in too and bout 20 tubes of silicone no more leaks. Also check portholes. A high powered led penlight during a heavy rain will work wonders.

CaptTom · 06-07-2021, 08:51 PM

Quote:

Originally Posted by sailormike

... bout 20 tubes of silicone no more leaks.

This goes 100% against everything I've heard and experienced. The only silicone allowed near my boat is in the grease I use on the rubber hatch gaskets.

I won't be "that guy on the internet" telling others what not to do, but I will strongly encourage the OP to do their own research about the right way to seal stuff.

**Comodave** · 06-07-2021, 09:05 PM

Keep in mind that once you go with silicone you can’t go back without sanding it off after lots of time spent scraping it off first. Maybe on glass, but where it attached to the frame if it does leak, nothing else will stick.

sailormike · 06-08-2021, 05:45 AM

The silicone used was what was recommended by the window mfg. I have the data sheetes directly from them stating the procedure and the product to use. There are some places where silicone was used by previous owners and i have been able to remove and reseal with no issues. I have also had to repaint some of these areas too with no special prep work needed.

Quote:

Originally Posted by CaptTom

This goes 100% against everything I've heard and experienced. The only silicone allowed near my boat is in the grease I use on the rubber hatch gaskets.

I won't be "that guy on the internet" telling others what not to do, but I will strongly encourage the OP to do their own research about the right way to seal stuff.

CaptTom · 06-08-2021, 08:06 AM

I agree that using it in accordance with the manufacturer's instructions for new installations (assuming a legitimate marine manufacturer) is appropriate.

But I've seen boats with globs of the stuff slathered all over the outsides of deck fittings, hatches and port lights. I just want to make sure no-one reading this thinks that's a good idea. (By the way, doing that does NOT stop the leaks. Nor does slathering on more silicone over the mess that you made the first time.)

sailormike · 06-08-2021, 03:58 PM

I agree! there were some places I found over four types of sealant on top and beside each over. RTV gasket sealant, silicone, window glazing construction glue broken down 5200 ect. NO sloobering the wrong stuff is just as bad as the leaks if not worse!

Quote:

Originally Posted by CaptTom

I agree that using it in accordance with the manufacturer's instructions for new installations (assuming a legitimate marine manufacturer) is appropriate.

But I've seen boats with globs of the stuff slathered all over the outsides of deck fittings, hatches and port lights. I just want to make sure no-one reading this thinks that's a good idea. (By the way, doing that does NOT stop the leaks. Nor does slathering on more silicone over the mess that you made the first time.)