23 center console Cap recore

[JW-Tex]

I have removed the cap and have it flipped over. The core in the bow are of the cap is completely rotted out and gone due to holes where the cleats were ripped out. The cap with no core had major sagging in the bow area when on the boat. Now that it is flipped over once I remove the backside skin what is the best way to core this area and any idea how to get the correct camber (get rid of the sag)?

I plan to use marine plywood and I assume I will cut out a piece roughly the correct size and then cut it into smaller squares about four inches each. Lay the squares on a layer of wetted out 1708 and put thickened resin in the cracks between the squares and then a new backside skin of 1708. Wondering if I will need to place some weight on the plywood to get the sag out and restore some of the camber to the bow area?

Any tips or ideas would be appreciated.

[Briguy]

What is the size of the rotted section? I think you may want to use
end grain balsa as your core. Somewhere on YouTube their is a complete restoration
of a 23 with core replacement of the cap. You might want to view it.
About a 15 minute video. Mettan marine perhaps.

[JW-Tex]

Thanks Brian...watched a couple of Metan Marine videos. Very helpful...wish I had their shop, tools, and manpower!

[RUSTYNTABATHA]

Just to add to this instead of another thread ... I want to use all composite on my 20 MA.... what should I use around the areas that will have increased stress such as the cleat area on the bow and rod holders and outrigger bases in the gunwales.... im going to nida or equivalent everything else ....

[shine]

Originally Posted by RUSTYNTABATHA

Just to add to this instead of another thread ... I want to use all composite on my 20 MA.... what should I use around the areas that will have increased stress such as the cleat area on the bow and rod holders and outrigger bases in the gunwales.... im going to nida or equivalent everything else ....

if you dont want to use plywood then a highdensity foam an be used in those places. Something like the 26 lb Carbon core foam. Use the honeycomb everywhere else and you will have a nice light/stiff cap.

[RUSTYNTABATHA]

so Honey comb in the areas that will have rod holders, pop up, cleats etc... ?

[Bigshrimpin]

Originally Posted by RUSTYNTABATHA

so Honey comb in the areas that will have rod holders, pop up, cleats etc... ?

exact opposite . . . Honeycomb where you DON'T have rod holders, cleats, etc. You want to use the HD foam or plywood where you mount hardware or any place that needs compressive strength or needs to hold a screw or bolt.

[FLexpat]

FWIW - somebody over on THT had a bunch of end grain balsa (1/2"??) for sale cheap about a month ago - didn't seem like tons of takers.

I have seen articles where guys made curved, cored shapes with epoxy (slow cure) by doing the 2nd layup using double cut core on a thin (previously made) panel with the edges supported, laying heavy polyethylene sheeting over the top of the completed layup with the edges raised several inches above the piece (think poly edges stapled to a wood frame?) and then put a few inches of water on top of the poly to get the right curved shape. Also seems like the poly would eliminate blush and give a very smooth finish if you get the wrinkles out.

[JW-Tex]

Ordered some 5/8 end grain balsa, checked the hull truth his was 3/8. Looks like the balsa will be easier than cutting plywood squares.

Thanks for all the help so far....now lots of grinding and sanding to be done.

JW

pic of cap before I flipped it


Swing sets are useful!

[shine]

Originally Posted by Bigshrimpin

exact opposite . . . Honeycomb where you DON'T have rod holders, cleats, etc. You want to use the HD foam or plywood where you mount hardware or any place that needs compressive strength or needs to hold a screw or bolt.

Yup, honey comb everywhere except for where you have fasteners. The honeycomb actually has excellent compression strength except for the edges (anywhere you cut a hole in it). It does not hold screw either, so that is the second reason to use ply/foam around rodholders, cleat, etc.

I would use 3/4" core, its really just barely heavier, but much stiffer than 1/2" core