Amid the excitement and anticipation of taking delivery of a new boat, one tends to discount the importance of certain items. In my case, when I switched on the “shower sump” breaker of my pride and joy and heard no pump running, I initially wasn’t too concerned.
During commissioning, however, I gave more thought to the drainage of the shower and decided to launch an investigation. Up came the floorboards and out came the flashlight, revealing, as I had suspected, that the shower drain fitting ended abruptly in the bilge. The breaker switch was a functional unit; it just wasn’t hooked up to any wires. No sump pump existed.
Since I was starting out with a new boat, I certainly didn’t want hair, soap, and other grunge slopping around in the bilge. The bilge was clean, and I wanted it to stay that way. I decided not to use the shower until I came up with a solution.
There are several ways to approach the shower sump problem. Both Rule Industries and Lovett make convenient shower sump systems that incorporate float switches and pumps together in a drain pan that fits under the head sole. These units retail for about $60 and $110 respectively. Either system would probably be fine provided room was available under the cabin sole. Unfortunately, there wasn’t room on my boat.
Another approach would be to have the shower drain directly into a pump, totally eliminating the shower pan. I tried this initially since the head had a drain fitting in one corner that I hoped would drain the entire shower sole. The fitting never drained the sole completely, and after a shower considerable water remained that had to be sopped up using a sponge. This was an unacceptable solution, to say the least!
I decided that the proper strategy was to design a shower sump pan that would fit into the limited space between the head sole and the hull. The pan would drain into the shower pump which I had previously installed in my earlier unsuccessful experiment. The boat manufacturer had already conveniently cut out an area in the sole into which the pan could be recessed. The existing teak and holly cabin sole insert would be removed and a teak grate fabricated to fit in its place.
The first step in the installation was to accurately measure the area to determine the pan size needed. I searched to no avail in the housewares departments of several stores to find a suitable plastic container or basin that could be modified to the required dimensions. A hand laid up fiberglass pan was just about the only alternative.
Considering the pronounced taper and deadrise of the hull in this area, I decided that a cardboard mockup of the pan would be in order. After all, it would be easier to modify a model to fit than to build a pan and discover a measurement error. The dimensions of the cardboard mockup were laid out on l/8” Masonite, cut, and glued together into a male plug using Elmer’s wood glue. I used Masonite to create a smooth finish on the inside of the pan, and to make it easy to remove the plug in case the molding decided to stick to it.
The completed masaonite plug was sprayed with PVA mold release using a Preval self-loading spray bomb. To guarantee removal of the plug, I also waxed the surface of the Masonite using conventional paste car wax. Since this was my first attempt at fiberglass lay-up I skipped applying gelcoat to the outside of the plug, instead going straight to fiberglass cloth. A single layer of lightweight cloth was roughly cut to the dimensions of the plug, draped over it, and saturated with polyester resin applied with a throwaway brush. I tucked in the edges as much as possible, and squeegeed out the air bubbles.
When dry, the plug was removed and the relatively fragile shell test fitted into the head sole for clearance. If the shell didn’t fit at this point, modifications could still be made without scrapping a completed pan. After establishing that everything fit, additional layers of fiberglass were added to the shell, building up to a total thickness of about l/4”. I found that saturated fiberglass mat is easier to handle than cloth and allows for a quicker buildup of thickness. Several air bubble voids inside the pan were filled in using fiberglass mat shredded with scissors and mixed with resin. This concoction looks like fiberglass-laced putty and will cover up any mistakes.
The inside of the pan was now ready for gelcoat to match the surrounding fiberglass. Since the pan will ultimately be recessed in the sole and covered with a teak grate, appearance isn’t critical and gelcoat may even be omitted if desired. I had previously purchased gelcoat from the boat-builder for another project, so I already had a supply.
Incidentally, for anyone having a relatively new boat or contemplating the purchase of one, I would recommend ordering at least a quart of gelcoat from the boatbuilder, just in case. If you have two-tone decks, order a quart of each color. You certainly won’t be able to get a closer color match, and your fiberglass man will be your friend for life if cosmetic repairs to your boat are needed in the future. The cost of gelcoat is minimal, about $6 per quart. To maximize shelf life, keep it in a tightly sealed container in a refrigerator.
Since I didn’t have sophisticated equipment for spraying the gelcoat, it was brushed on after being catalyzed with MEK (methyl ethyl ketone peroxide). You may have to experiment at this point to determine how much catalyst is needed. Usually, only a few drops are used in a small mix like this. The gelcoat flows like conventional paint and covers well.
Once the gelcoat had dried, the pan was ready for installing a drain. I used a 3/4” plastic through hull at the lowest point in the side of the pan. I even went so far as to grind the edges of the through hull to make it fit more tightly into the low corner of the pan. The through hull was then coated with silicone sealant and firmly screwed into the hole.
Since the pan shell had initially been test fitted into the sole, the fit after final lay-up was reasonably close except for some grinding of the bottom to fit the curvature of the hull. Because the finished pan was about 1/4” thick, it is strong enough to be manhandled and attacked by a grinder as necessary.
I then glassed the pan into place in the head sole, and attached the drain fitting to the sump pump with 3/4” hose. The sump pump used was a PAR diaphragm shower drain pump (part 36251-0000) that retails for about $163, but can be purchased from mail order catalogs for about $100. This may seem excessive, but the pump is quiet, sturdy, handles two gallons per minute, can be run dry without damage, and can be rebuilt. I also installed a PAR Pump-Guard strainer (part 36200-0000) inline at a spot that would be accessible for cleaning. The discharge for the pump was led through the bilge to the transom to a nylon through hull added well above the waterline. I did not use an automatic float switch because of the gunk that would be drained through the pan. You could add a float switch to the bottom of the pan if you wished, but I opted for a conventional circuit breaker switch mounted directly to the fiberglass hull liner at a convenient spot in the head. I installed an indicator light at the breaker to inform the showerer that the pump was in operation.
Finally, I made a cardboard template of the sole cutout for the teak grate and shipped the pattern off to H&L Marine, Inc, in Compton, California. H&L fabricates teak, mahogany, and oak marine accessories, and will quote on custom work. Since I had H&L make a custom teak cockpit grate on a previous boat I knew the quality of their work was first rate.
H&L recommended a grate thickness of I”, but due to space limitations I ordered one that was only 1/2” thick which is adequate because of the small area covered by the grate. If ordering a similar grate allow about a month for completion, and expect to pay from $50 to $100.
In operation, the shower sump drains quickly and has plenty of.capacity to handle even a full-pressure, prolonged shower. The grate must be removed for periodic cleaning but I’d still rather clean the mini-sump instead of my whole bilge.
Fiberglass supplies can be purchased locally or through mail order outlets. Since polyester resin does have a limited shelf life, check the expiration date on the can, if possible, before purchasing. Shower sump pumps can also be purchased locally or through the mail.
-Gregory Koveal
