Sealing the skin around minor hardware additions

[thinwater]

As a new PDQ owner I am just full of questions.

I am not new to boats and FRP repairs; I had a Stiletto for years that I made all sorts of rigging mods to, including constructing composite fuel and water tanks. However, it was a epoxy Kevlar honeycomb pre-preg and not vinyl ester over foam, so I want some practical experience.

The greatest fear is that water will get between the skins, freeze, and pop them apart. I know the conventional wisdom is to over drill mounting holes, remove some core, fill with epoxy, and re-drill and mount what you need. Certainly for anything stressed, and a backing plate too. In this case all I want to mount is a row of snaps to secure some cushions. They wouldn't need the strength gained by core removal, and I could simply bed them with 3M 5200. Do we know what the factory did under the snaps?

Has there been ANY experience in the PDQ line with delamination other than motor mounts? I will be doing it the hard way unless someone can convince me I am paranoid.

[James Power]

When mounting deck hardware its a good idea to countersink the holes to allow the sealant to create an O ring seal around the fastner. The countersinking also prevents the gelcoat from cracking when screwing into it. Give the area a wipe with acitone to remove contaminates and your ready to goop. 3M has come out with 4000 uv, its like 5200 but uv resistant. At PDQ the snaps were usually installed by the cushion manufacturers. James

[thinwater]

Thanks for the advise. Is it the same if the screws are going into a cored area? I imagine the skin is rather thin and that any significant countersinking would remove most of the skin.

[James Power]

Yes its the same for cored or solid. The outer skins on the cored deck and hulls has a layer of mat and tri axle so there is some thickness to it.The countersink doesn't have to be very deep. If there is core at the location its probably 1/2" so watch your screw length. James

[thinwater]

Thank you very much for your help.