Recoring Dech Hatches, strong enough?

[Boatboy6]

I ordered some dyvinicell h80 1/2" to recore some deck hatches (forward fish box and aft tank cover) on the SeaCraft. The largest hatch is 36x36. I plan on laying down a layer of matt or 2, bedding the coring in mertons hull and deck putty, and then lay down a layer of 1708 with vynlesther resin. Should this be strong enough? I don't want to have to worry about it and looking at the 1/2" I'm beginning to think I should have got 3/4" instead.

[pelican]

Originally Posted by Boatboy6

I ordered some dyvinicell h80 1/2" to recore some deck hatches (forward fish box and aft tank cover) on the SeaCraft. The largest hatch is 36x36. I plan on laying down a layer of matt or 2, bedding the coring in mertons hull and deck putty, and then lay down a layer of 1708 with vynlesther resin. Should this be strong enough? I don't want to have to worry about it and looking at the 1/2" I'm beginning to think I should have got 3/4" instead.

plenty strong !!!

[FLexpat]

That should be strong enough if the glass is done right. You might think about some 8oz cloth with the 1708 if you want to have better strength off-axis of the 1708 fibers. I would consider vacuum bagging it to help get voids out and make the resin/glass ratio better - if you don't have a vacuum pump then a shop-vac can pull ~5" of vacuum.

My Sceptre came with 1/2" balsa in the hatches. While they ended up with a slight dish shape after 40 years, I am pretty sure that is from how the edges were finished and not from the core being too thin. Blue Heron's Fiberglass 101 thread has my comments about proper finishing of hatches in it.

[FishStretcher]

I did 32x34 hatches with H80. Not scored. Matt on inside, no putty. Chamfered edges and two layers 1708 on top. Maybe 3. It is in my bass relief thread. Light, strong and stiff. I used vinylester. From mertons.

Edit. Schedule and construction here:

http://www.classicseacraft.com/commu...t=25405&page=7

[Boatboy6]

Thanks for the info guys, I think I'll pick up some cloth and it sounds like I should be good. I can always add glass if it seems too flimsy I suppose

[FLexpat]

I checked again and it turns out the original balsa core is only 3/8" not 1/2". I seriously doubt you will have flimsy hatches with that approach.

[Chaser]

Try two layers of 1208 instead of one of 1708. The 1208 takes bends and wets out better, a little easier to get it to lay down over the edge of the core. Use a finish router to round over the edge of the core and then run a nice fillet and the 1208 will lay right down.

I echo the comments on v bag as well. Makes a much better part and makes it easier.

I just redid the entire floor of my boat with 1/2" Divinicell, 1 layer 1708 on the bottom and 2 layers 1208 on the top, mostly all sections bagged. Strong as hell and very light.

[shine]

another option is to use one layer 1708, then a woven cloth over top. That will give you fibers in each direct and leave a smoother finish. One layer of 1708 would actually be plenty for strength. Bevel the edges of the core and it will conform very well. Here is a picture I took the other day of 1708 wrapping around a 2x4