Sunday 7 April 2013

Hatch seal replacement

Good day,

We had a tremendous amount of rain recently, with upwards of 3 inches of water flooding down the deck.  The scuppers weren't keeping up, and I noticed that the forward deck hatch (all original Atkins & Hoyle) were leaking.

When the sun came out I inspected the gaskets, which are round EPDM, set into a groove cast into the aluminium hatches.  They were all original, and very dry and brittle.

I contacted Atkins & Hoyle and discovered that while they can supply them (Parts Dept), they were VERY expensive:

Prices are as follows:

505C - $32.50 ea.
XR100 - $45.00 ea.
XR90 - $37.00 ea.
Glue for install $29.95 ea. (will need two tubes)
I got a rough quote from UPS, around $275.00 to ship (about 1-week delivery). I estimated a box 14"x10"x8", if you have some other friends at the marina or something I would be easy enough to fit more material in the box without causing shipping to go up that much. This may allow you to split shipping with another boater. 

As the kids say these days....OMG!  The total bill approached $600.

I found a manufacturer in New Zealand that stocked identical items (Rubbermark Industries) and purchased everything I needed for less than $100NZD.

I picked a fine weather week, and started by removing all of the portlights (there are 7...sorry...you know this).

They are held to the frames by stainless steel hex bolts with 4mm heads.  They are of course corroded into the frames, and needed some WD40 to break free.  One of them sheared, but I can replace the seal in place in a pinch.

Here's what I did:

I removed the old seal, it came away very easily, but on some of the portlights there was a bead of rubber sealant left behind.  The best way to get this off is to simply rub it with your finger.  In all but one case this caused the whole lot to peel up.  The problem child required some time with a scotchbrite wheel at the end of a drill.


Old seal

Close-up of old seal




Once clean of adhesive, I wiped the channel out with paint thinner.  I took a roll of the proper sized gasket (there are two sizes, the portlights take 1/2" or 3/8", the larger hatches take 5/8", and laid it down into the groove.  You must used soft-faced clamps when turning the corners and make sure not to pull and stretch the gasket when measuring (you want the gasket completely un-loaded and resting in the groove).  When you get the length right, cut it straight with a razor.

Pull the gasket back out and wipe it with paint thinner (or similar).  Lay a bead of silicon at the invert (bottom) of the channel about 1/4" wide.  Press the gasket back in and clamp it very lightly in place with soft faced clamps (I have 10 of the pistol-grip clamps made by Irwin)


When the silicon "kicks" and is a bit firm, remove the clamps, wipe the gasket carefully with thinner if any silicon has oozed up too far, and put the old gasket on top of the new gasket (because you've been insanely-careful, you won't have silicon everywhere and this will be possible).  Then place a small bit of plywood on top of this...then, like turning a cake over (call the missus), turn the hole thing upside down onto your workbench.  Put some weight on top evenly over the portlight face (another sheet of plywood and a brick), and now you have an evenly distributed force pressing the new seal into the channel and the silicon.  Leave it like this for a day.
Why put the old gasket on top?  Because if you look at the portlights you will notice that the gasket is not proud all the way around...if you just turned it over on the workbench it would rest on the aluminium, not the rubber.

Once everything had fully cured, I polished the lexan with PlastX and cleaned the frame of all grime.

I reinstalled the portlights with new 316 stainless hex-head bolts, adjusted the lever-arm dogs to suit (the black lever-arm dogs are adjsuted inward as the gaskets begin to compress and age...you MUST back them out with new gasket or you will never get them closed).  Back off the 12mm nut and use a hex key to back the bolts out of the frame).

The finished product doesn't photgraph well, but the clarity is great, and the seal is PERFECT!