Monday, April 29, 2013

Bending the Bomars

The Bomar deck plates I installed in the Black Pearl never kept out the water like I hoped they would. Sometimes they would remain "relatively" dry while other times, they would leak like freakin' sieves!! It was starting to get on my nerves.  You see, the Black Pearl is a very low volume boat and is, first and foremost, a roller. In other words, the decks (and hatches) are almost always either awash or completely under water. Leaky hatches are not a good thing in this type of craft!!!

I could never figure out why sometimes the front would leak while others it was the rear. That is, until I looked at one of the hatches and saw that it was slightly bowed. In other words, it could not get a good seal. So, depending on whether I had that plate in the front or back (they are not tethered) that is where the most leaking occurred

With this knowledge, I decided to take out the twist and make the hatch perfectly flat. Which I did. But after some testing, it was still leaking. The hatches, while tight at the toggle handle and lip opposite, were pretty slack on either side. I decided to take it one step further and put a pronounced curvature in the hatches. With the side of each hatch slightly curved down, once the handle was clamped down, the sides would be forced as well. In theory anyway.

Time to test!!

Pre-bending the hatch.

Using a heat gun to soften the material.

Cold water to "set it up"

Voila. Nice curvature.

Prior to making the curves, these hatches would simply slip into the coamings and a twist of the handle would slightly clamp them down - but no real pressure on either side. In the image below you can see that by now clamping the handle, there will be increased pressure on the sides!

Even with the extra sealing pressure from the curvature, I was still getting some leaking. I knew that I needed to make the rubber gaskets a little higher for added hatch to coaming contact!!  I decided to go with bicycle inner tube. In the picture below you can see that I laid a layer of inner tube under the existing gasket and pressed it into place. The two fit perfectly with a nice tight seal. No need for any adhesives or sealers.

Inner tube undeneath.

A little bit of trimming of the excess tubing. Tube and gasket pressed into place.

The addition of the inner tube raised the gasket just slightly but certainly enough to increase the pressure between the hatch and sealing edge on the coaming. Pressing the hatch into place now takes a little bit of effort and the locking of the handle gives that extra little sealing power!!!


I did some testing by throwing buckets of water over the hatches and, unlike before, there is no water, whatsoever, entering the boat. Off to the pool tomorrow night (Tuesday) for the real test.

Fingers crossed!!!