floor recore, 5/8 ply

[aquaprouts]

Crunch time restoring my 77' 196 with numerous projects heading into boat season. I have removed the floor topskin and wet, sagging plywood core in a 4 foot by 30 inch section directly in front of the engine and between the stringers...what i found interesting and perhaps contrary to discussions is that my plywood core is not 1/2 inch but is 5/8 inch. Has anyone else found this to be the case? What is the best/cheapest way to bond the new plywood into the bottom glass skin/shell and to rebond the topskin so it so it levels correctly to the existing topskin/nonskid.....thanks in advance

[dbiscayne]

a few things to sort out-
Is there any support along the edges of the repair area?  stringers along the sides?  what about front & back?
I wouldn't count on the old bottom glass skin to provide all the support.
If theres not, you might want to add a shelf to the bottom of whats left of the old deck to support the new panel, or put a 45 degree cut along the edge of existing & new for support.

Is the old non-skid top skin still salvageable?  If so save it, clean up the edges, & last step bond it to the new core so it matches the rest of the deck.
If it's trashed then you'll have to figure out how to finish the top of the repair.  Aesthetics isn't my thing.

Heres what I'd do-
Grind the gel coat and a little glass thickness off the top of the old deck all the way around the perimeter, about 2 inches, so that in the end you can lay a layer of glass across the old & new.  Use a tape line to get the ground off area as straight as possible.

If you're coring the new panel with plywood make sure you seal the edges good.  Give the new core a layer of mat top & bottom before laying it in & let it cure.  Then some thickened resin troweled onto the old bottom skin/new shelf? & edges & lay that new core in.

Figure out how much glass you need to add to the top of the new core to get it level factoring in using the old top skin thickness + a little thickened resin, if you can re-use it?

Last layer of glass will be across the old deck where you ground off the non-skid and new deck.  Then resin glue the old top skin to the repair, leaving you with a 2+ inch area of smooth deck around the repair.

[gran398]

^^^^^^^
Excellent

Aqua, if you want to get fancy on the finish....they make a diamond-skid thin fiberglass sheet that will glass right in as the last step....roll or spray gelcoat, you're golden.

Can't remember who makes it...they come in various diamond patterns and diamond sizes. Should be able to google it easily enough. There is one available that matches perfectly.

Good luck sir!

[seabob4]

^^^^^^^
Excellent

Aqua, if you want to get fancy on the finish....they make a diamond-skid thin fiberglass sheet that will glass right in as the last step....roll or spray gelcoat, you're golden.

Can't remember who makes it...they come in various diamond patterns and diamond sizes. Should be able to google it easily enough. There is one available that matches perfectly.

Good luck sir!

Also check out Gibco for non-skid...http://gibcoflexmold.com/

[gran398]

That was the place SB, sweet!

Here's the product needed

http://gibcoflexmold.com/patterns/?filt ... ttributes_[boat-manufacturer]=AQUASPORT&filtering_attributes_[pattern-type]=Positive+%28male%29

Search: AQUASPORT/male

[aquaprouts]

I have plenty of good edge to bond/hold the new drop in plywood....the bordering existing plywood is dry and fairly sound so should be an easier repair...is poly suitable or is epoxy much better?...the old nonskid is salvageable and i plan on rebonding to the new ply....just a bit worried that by adding mat/cloth that it may adversely effect the finished height of nonskid rebond....can i avoid using mat if i use epoxy?...what is the ideal epoxy?..thnx!

[dbiscayne]

Epoxy seals the wood much better than poly.  I'd at least use epoxy on the bottom & sides of the new core, & the edges of the existing.  Then poly on top if you're going to gel coat in the future.  If you're not going to spray gel coat then just use epoxy all the way, for the small amount of resin you're gonna need the cost savings of poly won't be much just shop around for epoxy you can get it for +/-$50 gallon.

If the bottom of the new wood core is sealed up really good with epoxy (thin w/acetone or epoxy thinner + one regular coat + thickened to glue it down) you could avoid the mat, all that resin is best coated simultaneously wet on wet.

Could probably use 1/2" ply for the new core too, give yourself some wiggle room for build up.

[Aquasport Commodore]

First off, if it was me, I would be leery of using the bottom skin of the deck for a number of reasons. If that wood already rot that was there, how do you know that the bottom skin is not already compromised in some place you can not reach or see? How do you plan on fixing that? You also need to make sure the core is the same height as the rest of the deck. This is a whole lot of work for not much gain. I take it from reading your post that you saved the top skin.  You still have the cover the ply with fiberglass and then attach the top skin. You have a lot of work to do this.

If it was me, I would use Nidacore or some type of composite board, https://www.apdmro.com/Honeycomb-Core-H ... 476637.htm which is the same price as plywood and lighter and works the same as wood. Use the 19 or 20 mm as that is the 3/4 inch equivalent. Do 1 layer of 1708 on the bottom, 2 on top for the entire floor and put new paint and nonskid down using tape for making a pretty pattern and your done. As for shipping from the above company, if your order is over $350.00 its free shipping, and that's the entire order not just one product and they have a lot of products you can use. Yes that does include your big panels. Before that magical $350.00 the cost of shipping alone is more than that. I am not affiliated with that site, just found it on my searches for supplies.

Epoxy something like this in the areas where you want to fasten anything down http://www.jamestowndistributors.com/us ... lass+Board and your done. While your under your deck, I would also check your stringers for water.

If you go the wood route, coat the entire (sides as well) new ply board in epoxy along with the exposed wood that is remaining on your liner to stop any future rot. If you haven't bought your epoxy yet, look at US Composites as they are the best price around.