Hatch Waterway Mold

[ecgossett]

I was looking at the photos at http://sailnaway.blogspot.com/ which is the same as the hatch mold I made. How many layers do people average for fiberglass coverage?? I usually make everything a guarenteed two with some overlap and extra layer or two at corners and ends. When I have removed it from the mold I brush a layer of epoxy on the back. Any thoughts?

V/R, Edward

http://coresound17.blogspot.com

[Ray Frechette Jr]

I find it much easier and neater to build wood hatch gutters rather than glass ones.

Built a few glass ones and threw away the mold as it was easier and quicker and cleaner to make wood ones. Scraps of wood for triangular pieces fore edge. glue and screw some cleats under seat hatch opening perimeter and then glue on triangular pieces to it and straight piece along back. Once cured a small wood piece dimension goes for bottom and then once that cures the inside pieces.

[Hirilonde]

Cold molding is a process using diagonal wood strips and epoxy to build a boat. It is in effect making boat shaped plywood with the grain on the bias in 2 directions.

As for hatch gutters I can't see making a mold and producing them out of fiberglass and resin being worth the effort. Do something similar to what Ray suggests.

[Peter HK]

Hi Edward

I think the last 2 replies missed the point that you have already made a mold and built a gutter frame and was questioning how thick a layup is needed. I can't help you other than a wild guess ( I built wood ones) but maybe others who have built a glass frame will chime in on how many layers/what weight of glass they used.

Cheers

Peter HK

[Ray Frechette Jr]

Ii used 4 thicknesses of 10 oz cloth when I made mine.

Even if I had the mold still in the shop though I could not eb convinced to use it instead of building with marine ply.

[ecgossett]

Thanks for the answers.. The only question I have left involves the hatches and the stringer that was left inside when cutting them out. Does this normally get cut out or is it accounted for somewhere else?

I could Hatch photos I looked at moved the inside lip for the drainage channel further back to leave room for this. Any thoughts?

- Edward

[wkisting]

As I recall, I chiseled away the stringer from each of my hatch lids and replaced it with a nice smooth epoxy fillet and one or two layers of 6 oz. FB tape. Then when I built my hatch rims (out of marine ply), I recessed the forward face of each hatch rim so that its top edge would seal against the flat bottom of the hatch cover, rather than against the epoxy fillet. I think I just epoxied a 3/4" thick piece of wood to the front inside of the hatch (spanning the full width) and then attached the hatch rim behind that. As a result, the front face of each hatch rim is about 1" back from the face of the seat --> 1/4" seat face thickness + 3/4" wood spacer = 1" recess). Then I also epoxied a 3/4" thick wood backer along the lower edge of each hatch cover. That way, I had a solid wood backing on the hatch cover and seat face (i.e., along the front hatch seam) in which to screw-mount hardware (padlockable hasps) for keeping each hatch closed.

Hope that description made sense.

[Peter HK]

Hi Edward

I'll add another variation on hatches. I made mine with a larger entry by lowering the front face an inch or 2. This is common practice on production boats to allow ease of access. What this means is that you have to run the seal around the front of the gutters and across the front of the recessed ply face at the lower part of the vertical part of the hatch seat.

This means you don't have to cut out the stringer in the hatch lid except for an inch at the ends. As long as there is a reasonable ring frame you can have a larger hatch. It certainly is as watertight as these hatches can be, as evidenced by the photo below after a capsize test.

Hope that makes sense.

Cheers

Peter HK

[ecgossett]

Hi Edward

I'll add another variation on hatches. I made mine with a larger entry by lowering the front face an inch or 2. This is common practice on production boats to allow ease of access. What this means is that you have to run the seal around the front of the gutters and across the front of the recessed ply face at the lower part of the vertical part of the hatch seat.

This means you don't have to cut out the stringer in the hatch lid except for an inch at the ends. As long as there is a reasonable ring frame you can have a larger hatch. It certainly is as watertight as these hatches can be, as evidenced by the photo below after a capsize test.

Hope that makes sense.

Cheers

Peter HK

Thanks Peter, I already tried one the other way http://coresound17.blogspot.com but will do the rest your way.

- Edward

[ecgossett]

If anyone is needs a seat mold let me know and I could sent it your way! The only upgrades it needs is a piece(s) to match your inner framing for seat unless you want to cut it out on the fiberglass post mold. I put in a back piece of wood for hinge screws to go into, and it held glass against mold. Some small strips of plywood might be put along inner walls of mold to increase strength if you are only doing 2-4 layers of tape.

I just Duplicolered lined my waterway with the rubber truck bed liner. Make sure you spend the extra $5 and get the better rubber kind with kevlar that attaches with minimal prep to surfaces. Word of warning 2 feet of plastic around area and having it taped off was not enough. The spray is messy and I'm glad the boat is only primed inside due to black spots.

My kids left some presents from sailing yesterday in the bottom.