help building glass hard top

[juicyhook]

Ive been working on my Rybo runners center console over the past few weeks, it coming together. So I figured Id spend this week off working on the top for the boat. The frame is built of 2x6's and I traced the camber off the transom. I then covered it with 3/8 plywood and a very smooth brown compressed board. Marked out the shape of the top and covered it with 5 coats of mold release wax.

So now I was at home depot and found the same board painted, this made the board just a bit more smooth. Im now wondering if I should replace my brown board with the painted board. It a bit of work but in the big picture its not a big deal.

So my questions are

Should I replace the board or will the 5 coats of wax be enough?

If I do is regular carnuba wax ok cause im out of mold release wax and can't get more till after the holidays

Im going to laminate it with1 layer of 1.5oz mat then 2 layers 0f 1708 on both sides and core it with 1/2" okume plywood.
Does that sound like a good plan or overkill.

Here is a few pics. Any other thoughs would be great to.

[Tarbaby]

One layer of 1708 is a plenty if you are doing a plywood core.. You could do foam and then use the layup you described. I assume you are going to be slick on the bottom and nonskid on the top? You can lay the bottom layer on with the mat towards the mold after you do the the 1.5 oz mat. The 1.5 oz mat wont hurt and it might help with the print through. I use that brown stuff for patterns. I like it for what you are doing. Post a pic when you get it done.

[rraabb1]

I agree with tarbaby. We build hardtops all the time. if you want the lightest possible top, do it this way.

after you wax your mold, spray it with a poly ester primer or gel coat. when it dries, place a layer of 1708 down on the cured primer then lay in a layer of foam core material onto the wwet 1708. You can actually vacuum it down with a shop vac and cheap plastic to be sure there are no air voids. you only need about 6-10 inches of mercury vac to ensure no air voids.When this cures you can use a router and route in any conduit you want and then cover with another layer of 1708. When it comes off finish the edges to your liking and prime sand and paint. Good luck

[Captain Jay Kavanagh]

I would build it out of foam, loose the plywood.

1/2" divinicell, one layer of 1708 all the way around should do it.

BTW Melamine (bathroom board) makes an excellent mold / laminating table.

[MarkP]

I would build it out of foam, loose the plywood.

1/2" divinicell, one layer of 1708 all the way around should do it.

BTW Melamine (bathroom board) makes an excellent mold / laminating table.

X2 except I'd use NidaCore-personal preference. Same on BR board; cheap, disposable, easy to use...

MarkP

[Judith A]

I wanted to do this years ago but had new soft top made.
A couple questions 1 how do you get the nice rounded edges not the curves but from top to bottom. do you do gelcoat on mold,glass,core then glass and then shape edge and glass around or is it built into mold
also are you going to use same frame work as soft top? mine has good 1 to 1.25 pipe around top so should be strong enough,was just thinking of removing few ribs that were needed for soft top
Thanks for posting you got my mind going on this again

Mark

[juicyhook]

Update

I was torn between the divinicell and the plywood but the plywood won. I know it going to be heavier but I realy like the idea of it being able to hold a screw and I already bought it.

All together it should be under 140# if id did my calculation correct.

So I started with few coats of white gel. Then a 6" border of 1.5 mat just so there was some meat to finish the corners off with. Then a single layer of 1708 overlapping the area where my hoop will lay for my frame. Tonight I notched and trimmed the plywood for my shape, when I did this I left a 1 inch area around the fiberglass border. The plan is to cabosil/millfiber the plywood down then pack a 3/4 ring of cabosil/millfisber
around the outer edge of the plywood to have a thick rigid area to create my bullnose. Basiclly it will be a sandwiched piece of resin/cabosil/millfiber between 2 layers of glass.

Any thought to that? good or bad.

Plus Im almost certain the notched side of the plywood goes up correct?

[Questsportfishing]

try to learn some vacuum bag stuff though it will make what you already know go way past anything you have done on finish. pluss the batteries are heavy..

[Captain Jay Kavanagh]

Batteries work as great clamps, so do cinder blocks.

I really dig your pilot house style center console, very functional.

Just be sure that every where you screw something into that plywood that you seal it with a good marine sealant. I am a fan of 4000 or 4200, you can get it back out.

[Judith A]

nice pics of your progress,are you going to put wood further out to sides? and is there an easy way to form bull nose or is that just a knack and lots of sanding to form round edge
Mark