17'0" Bow Hatch Recore Project

[TooLoose]

I need to recore my starboard and port side bow hatches. I have almost no experience with fiberglass, but think this may be a manageable project. Any insight/references you can share would be extremely helpful.

1.   Remove existing core material
2.   Grind down existing core material to “top-side” glass
a.   Given the existing core is only 21.5” x 10.5”, is it fair to assume I can remove this with a little elbow grease, or would you recommend buying a grinder?
3.   Insert new core material
a.   What core material would you recommend?
b.   What type of adhesive is used between the top-side glass and the new core material?
c.   Would the outer edges of the hatches need to be grinded down as well so the new glass would adhere to the surface?
4.   Lay down new “under-side” glass
a.   I have read a few threads which used two layers of 1708 mat, would this suffice for this project?

Given this is a relatively small project, would I be able to buys all the materials in a “package” like a west systems (minus the new core material), or would I have to itemize the materials?

Thanks for the help!

Mark

[RickK]

You have studied well.
What I did was use a cut-off wheel and slightly cut into the glass around the coring edge where it meets the inside of the lid. So now I have cut it all the way around and can now stick in a stiff putty knife and then a pry bar to pop the core off the hatch.






Then you grind the existing glass on the hatch down and any wood that was stuck to the hatch cover. I ground all the glass that was holding the core, so essentially the whole inside of the hatch.


As I started recoring, my hatch had a crack from people (me) stepping on the edge (you can see the crack at the top of the pic above) so I laid in a layer of 1708, covered it with plastic and weighed it down on a flat surface to harden. I used epoxy.
Then I lightly scruffed the 1708 with 80 grit to get it ready for the core. I used Plascore (honeycomb) for the core and beveled the edges to make it easier for 1708 to traverse the edges. I then troweled thickened epoxy resin onto the hatch, set the core into the resin and then weighed it down with cinder blocks on a flat surface until it cured.


Then I dry cut in the top layer of 1708 and lam'd it in. After it cured I cleaned it up and eventually coated it with epoxy bilge paint.

[TooLoose]

Thanks, Rickk.
I think I understand the process, and that also helps with the materials I would need to complete the job. Thanks for the response.

Mark

[Capecod]

An alternative and lower labor approach is to get a piece of King Starboard the right thickness and use the old hatch cover as a template to mark and then cut new covers. I did this on a whaler and the result was great vs. all the work. 

[RickK]

Recoring leaves the original non-skid.

[TooLoose]

I thought about that Capecod, but to Rickks point, I need to try and keep the original non-skid. The whole deck is a seafoam green color, which matches the hull. Would be hard to replicate.

[Capecod]

Makes sense- I was working with white and was able to get a pretty exact match to my eye.