Delamination / Core repair Lazaret

[RLaird]

Before I go overboard on this bit of core repair on a lazaret. The main damage was at the bedding of the hinge screws but I can't decide whether to remove all of the glass down to the core or just the part that delaminated. Might be easier to make it look 'nice' if I removed all of the glass but not sure it will yield any more strength.
The biggest challenge is mating the glass at the lip and keeping the depth flush when the hatch is closed.


Thanks for your comments...

[Spot]

Hello R-

Ideally you'd keep the outside glass shell (the hardest thing to remake and match to the rest of the boat) and replace the plywood and inner fiberglass skin.
Was there an inner fiberglass skin? Was the plywood factory or an addition?
I am not used to seeing gel coat on the inside of hatches at least not on my boat.
I am also wondering about all of the drilled holes on the one side...
I am looking at some core repair myself so I am also interested in the group's thoughts.

[psk125]

Looks like you've removed all the fiberglass that needs to be, and then some. Since the ply underneath seems to be fine, was it delaminated from the fiberglass? Will the cuts into the plywood weaken the seat and lead to cracks in the fiberglass later? It might have been better not to have cut so deep. There is no need to make more work for yourself by taking off more 'glass, unless you intend to replace all the plywood core. What are all the holes in the plywood for? Many people try to dry out the core by doing that. Then, when they put epoxy back over it, the epoxy traps any remaining or new moisture from being able to evaporate, and rot ensues very quickly. You do want to use epoxy resin, rather than polyester resin for the repair because the epoxy will stick better to the plywood. To make it pretty, give it a coat of paint when you're done. It's the underside of a locker - no one is going to see or notice it.

[tkeithlu]

Ho, Boy. Spot and psk125 speak with wisdom. First, does it need more support, or is it structurally sound as is? If it needs more, a vertical strip of wood or two glued in place (very well) before proceeding would make it more rigid without adding too much weight.

Then, dry that sucker out big time, probably in a warm but air conditioned space.

Then, seal it up with epoxy or polyester. Cloth maybe.

Hello, Media. I'm Swarthmore 1968. Were you around the morning that the Media Local slid right by Swarthmore, on accumulated butter from the dining room? Does the black RR bridge still have "Lionel" on the side?

[Spot]

Picture of the rear hatch on the Southwind 21 showing glassed strips for reinforcement rather than plywood. No the most elegant but going on 40 some years. Only issues are where previous owner opted for bare wood on various blocks to catch hardware.

[Cheechako]

Make it solid glass at the screws, then just enough core to keep it from being very flexy when standing on it. The core can easily be 2" or more from the perimeter.

[RLaird]

Thanks Folks,
The Lazaret has been sitting in the basement since last fall when I made a temporary plywood substitute. The glass was removed as it had delaminated from the ply but most of the ply was ok except at the hinge screws.
Prior owner appears to have some some kind of a bandaid repair that allowed things to deteriorate.
I want to try and make it look cosmetically good to match the opposite side and hope to have the result be as stout as original. Both sides were factory glassed and gel coated with nonskid exterior. While it is a Pacific Seacraft, there are areas where the workmanship wasn't quite up to snuff you might say.
The drilled holes were from when the glass was still there and I was considering letting it dry out thru that 'method' but decided it might never truly dry so I continued to excavate!
I know there are some pretty good YouTubes to key on as well but glad you think the dry core can remain. I will fit the new marine ply block and thru drill both hinge screw sets to fill with epoxy and redrill to prevent future occurrence hopefully!

[garyfdl]

My two cents:

Over drill the screw holes in the plywood to 1/2" (give or take).
DON'T DRILL THROUGH THE FIBREGLASS ON THE OTHER SIDE!
Fill holes with epoxy filler.
Cut a piece of plywood to match the rectangular piece that's missing and epoxy it in, fair with epoxy filler.
Drill 1/4" holes in the remaining plywood, including the new piece and the area still covered by fibreglass (pegboard makes a good drilling template). Again, don't drill through the fibreglass on the other side.
Saturate the plywood with several applications of thinned epoxy, including the wood still under the glass via the drilled holes. A small syringe would be usefill to fill all the holes.
When cured (couple days) rough sand the ply and the fibreglass.
Coat with a layer of regular epoxy.

Or, if you're more anal than I am, skip the last step and:

Cover with a thin layer of woven fiberglass, saturate with epoxy, and vacuum bag till cured. (On a piece this small, you can cob up a vacuum bag rig with a garbage bag and shop-vac.)