KATAMA Deck Delamination

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Nathanael Greene
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Joined: Mon Jul 25, 2022 11:54 pm

KATAMA Deck Delamination

Postby Nathanael Greene » Tue Jul 26, 2022 12:16 am

Q1: how can delamination of the deck in a 1969 KATAMA be repaired?

Q2: could small holes be drilled in the deck in the delaminated areas and then a syringe used to inject a resin under the deck and then weights placed atop the area in order to re-adhere the separated areas?

BACKSTORY
A few spots on the deck of a 1969 KATAMA have delaminated from the underlying material and move under pressure, that is, they more than other places on the deck move under pressure. The delaminated areas are on both port and starboard at the stern and are along the groove that runs around the deck. The delamination extends toward the centerline about six inches.

My Brothers and I are refurbishing a [1969--ALWAYS USE FOUR DIGITS FOR YEARS} Katama and trying to learn about fiberglassing. We want the refurbishment to be done right.

--Nate

jimh
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Location: Michigan, Lower Peninsula
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Re: KATAMA Deck Delamination

Postby jimh » Tue Jul 26, 2022 10:45 am

Nathanael Greene wrote:Q1: how can delamination of the deck in a 1969 KATAMA be repaired?
Typically the deck of a Boston Whaler boat will be reinforced with underlying plywood. A soft deck generally indicates the wood as become soft with water or rotted.

Visit the REFERENCE Section article on the 16/17 foot hull at

https://continuouswave.com/whaler/reference/16-17/

Consult the wood locating diagrams that are available in the REFERENCE article under the subsection EMBEDDED WOOD. I expect that the appropriate wood locating diagram will be the c.1962 wood layout drawing.

If the soft portions of the deck on your KATAMA are in areas where there is embedded wood, the cause may be soft or rotted wood. If there is rot in the wood, perhaps a material sold under the brand ROTFIX might be useful to stop the rot. See

https://www.systemthree.com/products/rotfix-epoxy-sealer

I do not have first hand experience with that product, but its description sounds useful for the situation you describe.

Another penetrating epoxy product that is designed to stop wood rot is sold under the BOATLIFE brand as the product GITROT. More information is given in this search result.

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: KATAMA Deck Delamination

Postby jimh » Tue Jul 26, 2022 10:52 am

Nathanael Greene wrote:Q2: could small holes be drilled in the deck in the delaminated areas and then a syringe used to inject a resin under the deck and then weights placed atop the area in order to re-adhere the separated areas?
Your method sounds workable to me, although I have not tried that myself.

Nathanael Greene
Posts: 7
Joined: Mon Jul 25, 2022 11:54 pm

Re: KATAMA Deck Delamination

Postby Nathanael Greene » Mon Oct 10, 2022 11:42 pm

Update on the delaminated deck repair
The location of the delaminated areas of the deck was found to not be over the embedded wood areas of the deck. Gorilla glue was used in stead of epoxy. Gorilla glue expands as it cures and is urethane-based. I believe the foam in Boston Whaler boats is also urethane-based.

The Process of Repairing Deck Delaminations
  • marked out the area(s) of the deck that had delaminated
  • drilled 1/4-inch holes all over the areas in roughly a 2-inch grid
  • squeezed Gorilla Glue into each hole
  • wiped up any excess glue
  • laid wax paper over the glued area
  • put down boards over the larger areas
  • put bricks and other weight on top of the boards where there were boards and just put bricks and weights straight on the wax paper in other spots

Results
This repair procedure for deck delimitation worked great. A few small spots had to re-repaired because the glue hadn’t spread far enough, but that was an easy fix.

I also used this method on the exterior hull of the boat by using boards, clamps, and straps instead of weights to compress the delaminated areas back into place.

IMG_5797.jpg
Fig. 1. The area of the deck with drilled holes.
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IMG_5800.jpg
Fig. 2. The glue in the drilled holes.
IMG_5800.jpg (18.11 KiB) Viewed 1306 times


IMG_5805.jpg
Fig. 3. A weight atop the repaired area as glue dries.
IMG_5805.jpg (25.37 KiB) Viewed 1306 times


This procedure may be helpful for others trying to repair deck de-lamination in older Boston Whaler boats.

Nate