Water Tight Deck Plate to Dry Out Foam

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Angus
Posts: 2
Joined: Thu Aug 11, 2016 11:23 pm

Water Tight Deck Plate to Dry Out Foam

Postby Angus » Fri Aug 12, 2016 12:33 pm

I am new to the Whaler Community as I have just purchased a 1983 13-footer. After having it now for a few weeks I am suspecting that it has wet foam. The hull is solid and has no [soft spots]. It is the topside that worries me. I do believe the floor has had a couple downrigger weights dropped on it.

I will be weighing the hull and doing a few other things to confirm my suspicions. If I do confirm it has wet foam my thought is to open up the floor with two six-inch holes, one fore and one aft, and install watertight deck plates. This would allow me to continue to use the boat as I wish and then unscrew the cover plate to help dry things out in the off days and over the winter when it will be stored upside down while I do some minor hull repairs. Once things have dried out sufficiently I would use the plug I cut out and fiberglass over the hole.

Any input on this approach would be appreciated.
Last edited by Angus on Fri Aug 12, 2016 4:59 pm, edited 1 time in total.

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Spinnaker
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Joined: Mon Jul 18, 2016 11:27 am
Location: Connecticut

Re: Water Tight Deck Plate to Dry Out Foam

Postby Spinnaker » Fri Aug 12, 2016 4:28 pm

Angus, congratulations. I love my classic 1981 13', which has a 1992 Mercury 40-HP four-cylinder engine. I think if you search the site, and take a look at the reference section in particular, you'll find suggestions on how to approach this particular problem, if it does indeed exist. See http://continuouswave.com/whaler/reference/FAQ/#Q3. Anyone who tells you they own a classic Whaler that has absolutely no moisture in the hull--well, I'll just leave it there. But beware of waviness and soft spots.

My concerns with your approach are that any water trapped under the glass will probably eventually end up near the bottom of the transom by operation of gravity, and in any case you'll be relying exclusively on evaporation to remove the water. Depending on what's in there and how much, humidity levels, etc. that could take years. The foam is quite dense.

One alternative would be to remove the brass drain tube at the stern, prop the bow up as much as possible, and try to wick the water out using towels and such over the course of the winter. I think you might be surprised by how much comes out. Another alternative is to drill a couple of small holes near the bottom of the transom that you can easily fill in later and paint over (if kept in saltwater). I've heard of folks using vacuum pumps to suck out trapped moisture. No matter what method you choose, you might want to temporarily remove the combined side lights at the bow just in order to equalize the pressure to allow the water to move. Many members here have tackled this problem using various methods and achieving mixed results.

jimh
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Re: Water Tight Deck Plate to Dry Out Foam

Postby jimh » Sat Aug 13, 2016 10:25 am

See the FAQ answer at

http://continuouswave.com/whaler/reference/FAQ/#Q3

If the dents from the downrigger ball weights have busted through the laminate, they could be a point of ingress for water. If the boat sat with water in the cockpit, some water could have drained into the inner hull space and been absorbed in the foam.

A test bore with a 0.25-inch diameter should reveal if there is water in the hull. As Phil mentions, drill in the hull bottom where water is most likely to collect.

A little wet foam is not enough to fret over. A rotted transom is a big worry. If the hull is strong and the transom dry, you can repair soft deck areas as you describe.

Angus
Posts: 2
Joined: Thu Aug 11, 2016 11:23 pm

Re: Water Tight Deck Plate to Dry Out Foam

Postby Angus » Wed Aug 17, 2016 10:39 pm

Spinnaker wrote:Angus, congratulations. I love my classic 1981 13', which has a 1992 Mercury 40-HP four-cylinder engine. I think if you search the site, and take a look at the reference section in particular, you'll find suggestions on how to approach this particular problem, if it does indeed exist. See http://continuouswave.com/whaler/reference/FAQ/#Q3. Anyone who tells you they own a classic Whaler that has absolutely no moisture in the hull--well, I'll just leave it there. But beware of waviness and soft spots.

My concerns with your approach are that any water trapped under the glass will probably eventually end up near the bottom of the transom by operation of gravity, and in any case you'll be relying exclusively on evaporation to remove the water. Depending on what's in there and how much, humidity levels, etc. that could take years. The foam is quite dense.

One alternative would be to remove the brass drain tube at the stern, prop the bow up as much as possible, and try to wick the water out using towels and such over the course of the winter. I think you might be surprised by how much comes out. Another alternative is to drill a couple of small holes near the bottom of the transom that you can easily fill in later and paint over (if kept in saltwater). I've heard of folks using vacuum pumps to suck out trapped moisture. No matter what method you choose, you might want to temporarily remove the combined side lights at the bow just in order to equalize the pressure to allow the water to move. Many members here have tackled this problem using various methods and achieving mixed results.


Thanks so much for the reply. I am going ahead this week with the 6" watertight deck plates fore and aft and over the winter leave them open to remove as much moisture as can reasonably be expected. Has anyone ever tried using calcium chloride in a large quantity sealed up in the boat over a few months in an attempt to remove the moisture?

dps616
Posts: 4
Joined: Mon Sep 19, 2016 7:40 am

Re: Water Tight Deck Plate to Dry Out Foam

Postby dps616 » Mon Sep 19, 2016 11:18 am

Angus,
Good morning.
I am doing the post purchase research on my 1986 13’ super sport and found that the hull has about 240 extra pounds. I found that the lower drain tube was leaking and took it out. About only 2 quarts of water came out. Your idea of putting in deck plates to get to the wet foam looks like a good one.
Have you tried it yet? If so, any success?
I was thinking about also putting in two 1” drain plugs in the stern so it can dry out year around.