Help wih recoring tank hatch

[tunacious]

I am going to recore the fuel tank hatch on my 23 Sceptre and would like the thumbs up from the pros before I do it. I used the search function but want to make sure I am OK.
The hatch is about 27 x 48.

This is my plan:

1.remove bottom skin from hatch and remove the old wood. .
( already done. 3/8" Plywood squares was the original core. )

2. Cut a piece 3/8 ply 1" smaller than than the hatch size. Bevel edge.

3. Seal plywood with one coat of epoxy resin

4. Wet out hatch with epoxy

5. Lay one layer of fiberglass cloth over the hatch

6. Place plywood on the hatch and hold down with weights
( Do I need to drill relief holes in the ply to avoid getting air voids)

7. Use thickened epoxy to fill in the gap between the plywood and edge of hatch

8. Wet out the plywood with epoxy and place bottom skin back on hatch

9. Use thickened epoxy to fair the the edge where the skin was removed.

[abl1111]

I used polyester resin and 1.5 oz matt, with 3/4" plywood. I like thicker but that's just me.

Be sure to put hatch on solid, supported, flat surface before you start to dig out the old wood and when you glass 'er up ( or, you will have a twisted hatch ). Chisel was best tool but be careful not to puncture through the skin ! Sand smooth when all wood is removed.

In the 1" space you left along the edges, be sure to lay a few layers of extra glass along there to strengthen it.

I did not use relief holes - it's been 12 years ! Still solid as hell !

[Boatboy6]

I also wouldn't re-use the old skin, waste of time. Just lay a layer of 1708 over the plywood and call it good.

[tunacious]

Thanks guys. Going to use epoxy due to the fumes associated with polyester. Doing the work in the garage and have to keep the admiral happy. I like the idea of using new 1708 as an alternative to the old skin. Abl, why did you go with 3/4 and did you leave the hatch
the original thickness around the perimeter?

[shine]

Originally Posted by Boatboy6

I also wouldn't re-use the old skin, waste of time. Just lay a layer of 1708 over the plywood and call it good.

this is right, its a lot easier to lay a new piece of 1708 down. If you bevel the core around the edge, the 1708 will conform nicely without slits

[abl1111]

I missed 'using the old skin'. Definitely, use new glass.

I used 3/4" because I had it laying around and wanted to be sure it was solid. Probably overkill, but that describes just about every part of my resto.

I beveled the edges and left about 2" around perimeter with no core, just extra glass.

I also did the same with the forward hatch. I had a twin i/o that I made into a single i/o so I didn't need the front fuel tank. Instead, I cut the hatch in 1/2, added (2) side edges where the center cut was made and re-cored, with SS lift latches. Gave me some extra storage. All hatches still rock solid.

The smell of poly - ' it smells like, Victory ! '

[Daysatsea]

I removed the hatch and cut off the skin above the old core. Chipped out the old wet balsa core and ground down the entire underside. Wet out the entire surface with poly resin and laid down at wetted out sheet of Matt, 1/2" core cell which I had beveled off. Wet that out and finished with a layer of mat and then a layer of woven. Covered the whole wet area with wax paper, laid it wet side up on the shop floor and added 200 lbs of weight to keep or flat.