Leaky hatches

Ram

Well-known member
Joined
Jan 26, 2009
Messages
86
Fluid Motion Model
C-248 C
Hull Identification Number
FMLT2511I607
Vessel Name
Akashi
I've had some serious leakage this past winter which I believe is coming in around several of my overhead hatches (this is a 2007 R25). I pulled a couple of the hatches from the top today. What I found was that the screws seemed to be a little loose, which was probably part of the problem. Mine were sealed with what looks like a butyl tape (brown). This strip seemed to be somewhat dried out. I put a wide strip of a softer butyl tape (grey) all around the flange and re-seated them. I feel pretty confident this will fix the problem, but we'll see. I need to get more tape to do the rest of the hatches. If your boat is more than a couple of years old, I'd suggest pulling at least one hatch to see what the condition of the seal is. You could prevent a lot of interior damage which I have to deal with next.
 
Ram --- I have an R25 of the same age and a hatch started to leak this winter. Right now I am using a bucket on the table to solve the problem. Too much rain here to take them apart. I am unfamiliar with butyl tape. What is the brand and where might I find it? Sounds like an easy fix but I would prefer not to use a liquid sealer. In the past, on other boats, I have used a thing called "hatch tape" that works well but crushes after a while. --- Cary ---
 
I do not know if the hatches used are the same, but we had the same problem on our 2007 R21, purchased last fall. I pulled the hatches and found several problems. The primary one is that they are installed with (sheet metal) screws and several were stripped due to inadequate holding and/or over tightening. Another problem on our hatches was that the screws on the hinge side were countersunk a considerable distance and therefore held salt water. One screw was corroded completely away, the other was not a great deal better. Those are both faults in design in my opinion.

Ours have a flat rubber gasket between the flange and the hull. That should work, but with loose screws water works right past it.

The first thing I did was fill the deep countersink on the hinge side with epoxy resin with some chopped fibreglass mixed in. Then I re-drilled the holes and used longer screws which are countersunk at the surface instead of being in salt-water wells.

It is not particularly nautical but I put two rows of "string caulk" around the flange, one on each side of where the screws penetrate. That compresses nicely, stays flexible, and does a good sealing job without gluing the hatch in place. Whatever you do, do not use adhesive caulks like "5200". We literally had to saw out a broken hatch on our Atlantic 44 on which some yard-bird had used 5200 when "seating" it. Yes, there is stuff that will dissolve it, but lots of luck when it is paper-thin on a 1 1/2" wide flange, That required that I completely rebuild the deck flange before I could replace the hatch.
 
When I went to accept my boat last year, there was a problem with the upper hatches. The dealer swapped out the hatches and I noticed he did not apply any sealant. I asked him about it and he said the factory does not use a sealant.

On my previous boats, I had some leaks around some windows and hatches. I applied silicone sealant - the same as I used around the windows and doors on my house - problem solved. What is nice about silicone is it stays soft and pliable, and has a 20 year warranty. If you should have to take the hatch/window off, it is easy to break the seal and clean off the old silicone.
 
I used a puddy knife to pry off the city fresh water regulator without too much trouble (thing burst a part) and Andrew sent me a new one. In my sailboat days we used something made by Interlux called "boatyard bedding" which stays soft and is perfect for seating hatches and such. I found Dolfinite Bedding Compound at West Marine and just about dropped dead when I saw it was $46.99 by the pint-the smallest amount they sell. Jamestown Distributors has it by the pint for for $21.83, which is still a lot of money. Still, this is the stuff you want to use under deck fittings, trim, mouldings, etc. If you need a quart, Jamestown sells the Interlux product for $30.71 per quart; no smaller quantity available. Either way, you'll have to pay an additional $5 for the hazmat fee on top of shipping! You can't win.
 
In this day of stronger is better, it is difficult to find a bedding compound that doesn't also "permanently" glue the surfaces together. And even for thru-hulls, that can mean trouble if replacement is ever required. Heat can be used on metal fittings, but most plastic ones will burn before the sealants let go.

My only problem with silicone sealants is that most will not allow another coat to adhere since it is so slippery by nature. That is not a problem in many cases, but on one boat we had which had the windows "glued in place" with silicone (no fasteners) it was impossible to stop the leaks once they started since each additional layer just added another tiny path for water to leak in. Silicone is best if the item is fastened with something other than adhesion. For instance you put a layer of silicone down and then screw or bolt the object in place. The best procedure is to leave the fasteners just a little shy of "tight" and after the silicone cures for a day or two, snug them down. What you have essentially done is to build a custom gasket which you then seat the part on when it cures. Our cruising sailboat had covers on the molded-in water tanks sealed like that and that works perfectly as long as you follow that procedure. The covers are still removable if you need access, and any additional layer (ever tried to get silicone off 100%?) when you replace the cover is compressed enough that the line between the layers will not leak.

Currently we are using LifeSeal for a general bedding compound. Not a perfect solution but not bad either as it does not have such a high-strength adhesion as some other products. I did not really want to "glue" the hatches in place, so the "string caulk" met my needs perfectly this time. (Mortite is the brand I used.)
 
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