Is it foam cored or is it solid?

[joe_mcginty]

I have a '79 222. It has a liner in the cabin. I'm about to drill my first holes in her to mount a couple of cleats. Here's hoping that in 1979 foam coring had not been discovered yet and I can just drill, seal and mount. Two questions: 1) Is it foam core or solid and how can I tell? 2) You can buy high-density foam at the craft store. How would it be to seal my cleats with gaskets made from foam instead of the 3M 5300 (5200?) sealer. Hoping there are no dumb questions.... Thx.

[DLT]

I'm no expert, but I thought the technique when encoutering foam or other coring was something like:

1 - drill your hole;
2 - scrape out some of the coring all around the hole; and
3 - fill that space with a sealant that will harden, such as an epoxy.

The idea is to seal the coring material up between the two f/g sides. Trying to gasket from either side is problematic, since you risk water intrusion, which will degrade the coring...

[Night Sailor]

According to a Practical Sailor review of a Mac 26, Mac boats before 1999 had balsa cores in deck and companionway hatch. In 1999 Mac switched to fiberglass stringers filled with foam between liner and deck.

I found balsa to be true of my 1998, also in the anchor well cover.

However, I seem to recall that on my 1974 Venture 2-22 which I owned back in the early '80s that I sawed through plywood for vents. Could have been a different boat.... memory fades as you accumulate so much fun with boats... it crowds out the difficulties...

[Catigale]

Joe - greetings from another Upstater - Im up I-88 near Albany of course.

For cleats you do want them backed onto something solid, so I would follow the filled epoxy advice below for those holes. More importantly, put some serious backing plates or washers on those cleats - at least an inch diameter.

If you are personally the type who looks after things carefully, I wouldnt be beyond just setting the cleats into a bead of 5200 to seal and then checking for water intrusion a couple of times a year. A cleat isnt going to move much - if it does, it will fail the hull, so ......You do have to do the epoxy thing on a foam cored hull to stiffen the FG where the cleats will stress the hull though - cant cut that corner. If its plywood, I would drill, seal, and watch closely.

If you tend to do and forget, then go the full route of sealing the hole so you dont get a soggy deck in 5 years....

You can also bed with 4200 which is easier to remove.