Builders' Forum Archives
Re: Leaky hatch - RESULTS
Posted by LeeG on Aug 4, 2005
Ray,,just to double check, with your flush hatchs,,how big is the recess and what exactly is the type of gasket that you are using? In other words if the hatch is 4mm thick(or 8mm) is there a gasket of sufficient thickness that it is getting compressed enough? The other solution is applying a raised lip on the underside of the hatch made out of a bead of thickened epoxy. Using a syringe you can lay down a thick bead of epoxy then as it cures come back and feather it out with a gloved finger dipped in alcohol,,it's not precise and may complicate things but it's a possiblility. Just to double check,,the webbing you are using,,it's polypropelene and not nylon correct? Nylon will stretch when wet and tighten up enough to break things when dry. What exactly is the closure mechanism? A fasteck buckle? Are you using some kind of slider buckle as you would on a seat belt where you're attempting to pull a loose end of webbing to tighten things? While you perfect the webbing technique cut up 16 oval shaped pieces of 4mm ply big enough to have a finish washer on one end. Sand them, drill holes, warm them up in the sun and dip them in warm epoxy, take out before any of the epoxy sets up and hang on a wire. After they cure, re-drill sand again and dip in varnish or any number of things that tickle your fancy. Assuming that you've risked relocating the webbing attachments from the sheer clamps to the edge of the hatch through the deck/spacer/recess,,,try one or two out on the hatch. If the hatch isn't flush enough for the toggles to hold the hatch down evenly then maybe that's the bigger problem but that can also be addressed by building a lip under neath the hatch where the gasket isn't compressed adequately or building up the hatch where the toggle doesn't get compression. This is one of those points where you might swallow your aesthetic complaints and go with what works. I've been pleased with using a combination of one piece of webbing and a number of toggles around the hatch as needed. It looks busy,,sure,,but I can see when things are working and can open/close the hatch with various degrees of certainty. For example if I need to close the hatch quickly and move the boat it's just the webbing and buckle,,a final closure before launching uses the toggles. Just to check what's the method of flush hatch construction you are using and does the curve of the hatch follow the deck? Is there any variation in the recess that's not following the hatch curve? Experiment with thickened epoxy and alcohol for smoothing on some scrap pieces of wood to make raised areas.
In Response to: Leaky hatch - RESULTS by Ray on Aug 4, 2005