Hull-Deck Joint Gelcoat Repair

Gelcoat repair after filling
After filling the damaged areas with epoxy, the next step is gelcoat.

In my last post I discussed the importance of the hull-deck joint and how I repaired it on the Key West 1900 center console currently in my shop.  Now that the structural repair has been accomplished, let’s talk about cosmetics.  After all, we want the boat to look pretty again. Our goal is not just good-as-new structurally, but cosmetically as well!

You can see how much excavation was required to get down to solid material.

As you can see, quite a bit of excavation and filling was required to get rid of all the stressed and cracked fiberglass.  Now we have to cover that in gelcoat, the same material that was used in manufacturing the boat originally.  The trick is to get a good color match.  After 20 years, even if we had a batch of gelcoat from the original manufacturing run, it wouldn’t match the color of the boat now due to the fading effects of the intense sun here in South Carolina.  So you have to blend your own color.

A plywood dam recreates a smooth sheer line for the gelcoat.

Having done that, I just layered on coat after coat until it was a little bit proud of the surrounding area, knowing that I would have to sand it smooth.  In this case, it was worth it to construct a plywood dam that recreated the curve I wanted in order to define the sheer line (the line of the deck you see as you look at it from the side).  With the dam in place, I could load it up with gelcoat and scrape it off even with the top of the dam.

Cured gelcoat after removing the dam, ready for shaping and final polishing.

Next comes the process of sculpting the gelcoat to the final shape.  You have to take your time, being careful not to sand off too much.  Of course if you do, you can always add another layer. But you have to wait a day for it to cure.  Finally, polishing to a nice shine, and a coat of wax completes the repair.  Good as new in all respects!

Hull-Deck Joint Repair

An 8 foot section of the hull-deck joint had failed underneath the rub rail.

The 1999 Key West 1900 Sportsman center console boat that we’ve been hired to re-power needs some other TLC.  If you’ve been following along, you know we checked the hull for water penetration and de-watered it in a previous post.

Hull-deck joint separation
This view from underneath shows how the joint has separated. I used shims to hold the joint apart so I could inject adhesive into it.

In my evaluation, I noticed that the hull-deck joint had separated for about 8 feet on the port side.  This is a key structural element of any boat, and an issue that needs to be fixed.  Key West uses a “shoe box” type of joint where the deck piece has a 1-1/2 inch flange that fits down over the top edge of the hull topsides.  The joint is hidden by the rub rail, and is screwed and glued with 3M 5200, a very tenacious adhesive.  Just imagine how much stronger a shoe box is if you glue the lid on.  If you try to push in the side of the box, under the flange, it caves in pretty easily until you glue it to the top.  Then it becomes a rigid, monocoque structure. Continue reading “Hull-Deck Joint Repair”