How to fiberglass engine hatch - Help Needed!!

[Blue Crabber]

Hey Everyone! Been hanging around here for a while and picked up a used 1985 Sea Ray 30' Sedan Bridge boat that is my fixer-upper project. Here are some pictures of the boat for those that haven't seen it yet:

First part that I need some help with is replacing the wood coring in one of the engine hatch covers that also creates the cockpit flooring.

Here is a picture of the cockpit of the boat with the hatches up, but you can get the idea of how they work. All 3 hatches are leaning against the transom of the boat and you can just see the bottoms of them in the top of the picture.

Here is a picture of the topside of the hatch:

And here is a picture of the bottom side with most of the wood coring removed:

And a few more Pictures:

So here are my questions:

I know that I need to remove the rest of the wood. Do I also need to grind down the old lip as well?

If I leave the old lip, do I grind the coating down to bare fiberglass or how do I make the new fiberglass adhere?

When I replace the wood coring, do I just put a layer of epoxy onto the top of the hatch and then lay the wood in and clamp in place until it cures?

I have plenty of West Systems 105 epoxy and 207 Hardner that I will use to fiberglass this in place.

How many layers and of what type of fiberglass cloth do I use?

I know that this is a lot of questions as this is my first fiberglass project. I have watched some videos and read some threads, but thought I would ask here to get information related exactly to my project instead of making assumptions!

Thanks in advance for all of the replies and help guys, you rule!

 

[oops!]

Re: How to fiberglass engine hatch - Help Needed!!

sticky situation you are in......that is a manufactured part.

by saying that i amean that the gell and glass were shot,,,,the wood core added wet on wet....then shot some more and finally gelled.

but it is an easy fix for you....and a good job for epoxy.

grind out all the wood......you want to bond glass to glass.

in the last pic.....(pic 6) you see pools of resin on top of the glass.......see how they are cracked and de laminating?....that is because the resin is brittle with no glass in it.......the resin has to come out....grind or flake all that resin out of there.

dont grind too deep and go thru the glass....just get to it.

then lay a layer of woven roving (even a thin layer of 12-17 oz over the glass and use the epoxy to glass it in...
at the same time, take your wood core....and coat the down side with epoxy till the wood soakes it up....dont leave any dry spots.

place the wetted out wood core in the recessed area of the hatch while the epoxy and fiberglass is still wet.

now take a thin layer of woven and coat the whole outside of the wood (the exposed top side that will be the underside of the hatch).

leave all factory edges alone.....dont glass in them or around them....do not glass any where where the new glass will inter fear with the normal closing of the hatch.

let cure 24 hours.
paint under side of hatch

re drill the hatch hinge holes....add epoxy to the holes....then add the hinges and screws....let cure 24 hours.

re install.

this entire job could be done in a very small time span......but the epoxy curing time is a real pita as far as fast production is concerned.


cheers
oops

 

[Blue Crabber]

Re: How to fiberglass engine hatch - Help Needed!!

Oops! - Thanks for stopping by, I was hoping that you would!

I really appreciate the info, it all makes perfect sense. I figure that I would need to remove all the old resin down to the bare fiberglass.

Just to be sure, I should grind out everything to the right of this red line? Then when I apply the new fiberglass cloth, I will recreate this lip going over the outside of the new core? I won't go any closer to the outside as this will get in the way of the hatch seating properly. Is this the correct method?

 

[oops!]

Re: How to fiberglass engine hatch - Help Needed!!

that depends on the recess for the hatch bud.

some of the hatches fit like a male female.

and the raised section of the core is a molded fit to the hatch hole.

if yours is not.....then the raised area in the red lines can go. and you can glass right to the edge of where the red lines are.

there are two things to watch for in this repair...

1. make sure that when you glass the new core in.......the old hatch is on a FLAT LEVEL support.

2, make sure that any part of the new glass that will come in contact to the existing cut out, is flat and level. and the same height as the old. (other wise, the fit will be un even....and will rock when you walk on it)

 

[Blue Crabber]

Re: How to fiberglass engine hatch - Help Needed!!

Thanks Oops! your are a gentleman and a scholar!

Dually noted on both of your points. I will make sure that I have a flat and LEVEL surface when I wet in the new core.

This hatch is more "old school" and doesn't mate up like some of the newer ones. The 3 hatches sit side by side, no overlap. But I will make sure that if I do get into the support areas, that I maintain the same thickness. If I stay to the red line in my picture, that shouldn't be a problem.

Thanks again!

 

[Bondo]

Re: How to fiberglass engine hatch - Help Needed!!

Ayuh,... Just my thought on leavin', or grindin' out the lip,...

Structure is strength,... The lip is structure..... 'n it's already there....

I think I'd do yer rebuild by doin' it as a drop-in redo...
Do just like Oops says, 'n just peanut butter in any gaps between yer plug, 'n the lip.....
It's already good glass, use it to help the edge fillet....

'n My thoughts on the Flat, 'n Level,.....
I built some 2x4, 'n ready-rod clamps,...
Just so's I can cause the center of the panel to be a 1/8" Higher than the perimeter.....

I know boats are never level, but built in pitch stops puddles before they happen....

 

[Blue Crabber]

Re: How to fiberglass engine hatch - Help Needed!!

Bondo - Thanks for chiming in!

I hear you loud and clear on the structure and the strength and how the lip creates that. However, do you think it makes that much difference if I grind it out and then glass a new one back in around the wood?

I completely follow you with the wood drop in and PB the gaps, however, I am confused about how to glass over the underside of the wood if I leave that lip there. Wouldn't I want the fiberglass to wrap over the outside of the lip? In that case, I would still need to grind down to fiberglass for a good mating surface, right? Seems like if I am going that far, I might as well take out the lip.

Maybe I am wrong guys, thats why I am asking! I would prefer to only have to do this once. Set me on the straight and narrow!