Removal of Water-soaked Foam and Repair

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
dtmackey
Posts: 760
Joined: Thu Sep 28, 2017 9:29 pm

Removal of Water-soaked Foam and Repair

Postby dtmackey » Wed Apr 27, 2022 9:42 am

While many will debate this, Whalers do absorb water if the foam comes in contact with water over time. While the foam is closed cell, it still absorbs water. I've worked on enough Whalers to see this many times above and below the waterline.

Years ago, the local Whaler dealer joked with me and said the only "dry" Whalers are the new ones on the showroom floor.

Here's one of the latest ones I've been involved with , and Outrage 18. The original bow pulpit had a leak through the deck and the large foam area under it absorbed a significant amount of water and froze over the winter causing the fiberglass to buckle and bow. The entire area had to be cut out, gutted, refoamed with two-part polyurethane 4-lbs closed-cell foam, and glassed over. This is demonstrated in Figures 1 to 7 below.

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Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

The foam had significant water content and you could squeeze it out like a sponge.

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Figure 7

Perform an annual inspection of all mounted hardware and fasteners, and especially the brass drain tubes as saltwater causes them to corrode.

I feel that wet foam in a Whaler is far worse in the North where it will undergo many freeze-thaw cycles causing other damage. Wet foam that undergoes freeze thaw cycles will compromise the Unibond between the foam core and fiberglass skin.

D-

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: Removal of Water-soaked Foam and Repair

Postby jimh » Wed Apr 27, 2022 2:46 pm

I like your method illustrated in Figure 5 for making a temporary dam to contain the expanding foam to the rough contour of the hull.

After the foam was cured and trimmed, did you re-fit the original hull laminate piece that was cut out?

Or, did you just create a new laminated layer into that rectangular cut-out?

dtmackey
Posts: 760
Joined: Thu Sep 28, 2017 9:29 pm

Re: Removal of Water-soaked Foam and Repair

Postby dtmackey » Thu Apr 28, 2022 3:58 pm

jimh wrote:After the foam was cured and trimmed, did you re-fit the original hull laminate piece that was cut out?

Or, did you just create a new laminated layer into that rectangular cut-out?


Since the inner glass skin was damanged (wrinkled) from the expansion of the foam when it froze, a new skin was glassed in and faired.

D-