Hatches

I built the night heron hybred last year and did not install the hatches. I have the opportunity to sell it to a good friend allowing me to build another one. He woulld like the hatches put in. I seem to recall reading on the forum that putting in the hatches at a later date is fine, and not a problem, but I am not sure. I wnated to know if there are any considerations to be aware of. Thanks, Mark


4 replies:

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RE: Hatches

Won't be a problem at all. The worst that might happen is a few scratches on the deck varnish. Those a can be avoided by covering the area with blue painters tape before cutting them out. You will want to seal all the edges of newly exposed plywood with unthickened epoxy. 

George K

RE: Hatches

I'm putting in hatches in my guillemot finished by the beginning of last year.

1. draw it on paper
2. mask the area and draw the hatch border on the masking tape
3. cut out the hatch with a jig saw (take the time it needs to not damage the lid)
4. glue one or more layers (1 used 2) of rather thin plywood (I used 1/8" birch) under the deck (about 1" wider than the opening) around the hatch opening. Make sure that the thickness of the whole thing (deck and plywood under the deck together) is the same everywhere
5. cut the glued in plywood layers so that it matches the hatch opening
6. the lip: make a plywood piece with a hole about 3/4" inches smaller than the hatch opening, and an outer border that matches the outer border of the already glued in plywood layer(s)
7. cut the lip inside of the hatchet opening so that its width matches the width of the gasket you want to use (I used a 12x15 mms foam gasket)
8. glue on the gasket
9. drill the holes for and mount the hatch toggles

Critical:
I first made a lip from glass and epoxy first. To make the hatch lid watertight, the lip must have precisely the same shape as the underside of the lid. If you have veeeeeery long arms, you can probably make the lip inside of the boat as described in some books. My arms were way too short for this. So I used the cut out lid as form to make the lip. I used six layers of glass, but the lip was still rather weak. After glueing in the lip its distance to the upperside of the deck was not the same in all places :-(( - and it did not fit to the lid at all. So I cut all out, and made it with plywood. That worked (see above).

I've not tried the approach to glue the plywood lip direct under the deck, but I can imagine that this will work too. I used a thicker gasket because of this is more forgiving to tiny "must have precisely the same shape as the lid" errors.

Happy hatching!

Paper Model for Hatch Opening

 

 

RE: Hatches

Thanks for the info guys. Next weekend is my target date to get this done. Mark 

RE: Hatches

I cut hatches out of my kayaks cedar strip deck with a Bonsai saw. Then I glued a ring of 4mm ply on the underside followed by another ring of 4mm - wider - to form a lip for the hatch. Nothing fancy for hatch seal, just foam tape. Hatches are held down with bungee = see CLC hidden hatch hold down system.

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