Since buying the boat, we’ve cleaned our water tanks several times. And despite the input generally being measurably high-quality reverse osmosis water from our water maker, the water coming out of the tap has never tasted good. The whole system is, as far as we can tell, original to the boat, and we kept finding chips and debris in the bottom of the tank, as material sloughed off the inside of the fiberglass tanks. So, we decided to do something about it: we would paint the tanks, and replace all the 25-year-old tubing. After a moderate amount of research, we selected a product called LiquiTile 1172, which is a solvent-free epoxy, certified (NSF-61) for tanks as small as 50 gallons.
The first step should be to sand the existing tanks. But to do that, we needed better access. Our water tanks are integral to the boat’s keel, and since they’re long and skinny, there are baffles built in to prevent the water from sloshing around. On the port side there were three compartments and three inspection plates, but starboard, there’s a fourth compartment that was inaccessible. So, we decided to add a fourth port. This involved drilling through both the floor and the top of the tank; Jazz did the honors. The location is also the same place where we step out of bed, so mindful of the possibility that this could be a future weak spot, we put the hole as far aft (away from the bed) as we could manage.
[Hindsight edit: If we did it over, we would put this further forward: the step is plenty strong, and the tank extends a long way forward.]
Here’s Jazz painstakingly sawing a round hole in the fiberglass with an oscillating saw.
Now that we had access, it was time to roughen up the surface so that the new epoxy would adhere. We started by sanding, but when we went to inspect our work (with our “poor man’s borescope” aka backup camera we’d bought for another project), we found that the coating (we’re assuming gelcoat) had delaminated and cracked in a number of places. So, all of that had to be chipped off, revealing the fiberglass underneath. Fortunately, all of that was only surface deep, so there was no need to add more glass or any other more serious repair, and the epoxy is just as happy to bond to that. The inside of the tanks are surprisingly hard to photograph, because they’re tight and white on white, but here’s me on sanding/chipping duty: the edges of the holes are sharp, but it’s too hot here to wear a whole shirt, so Jazz helped me deconstruct a “work jacket” to improvise vambraces and protect my fragile forearms.
[Edit: This prep phase is really important! The smoother you get the surface, the easier it will be to keep your tank clean. If your surface is rough, consider adding epoxy with a fairing filler, kind of like spackle.]
So, having chipped and sanded, it was time to paint. As I’ve mentioned once or twice, it’s hot here, even in the mornings. Epoxy cures faster in the heat, and this particular epoxy isn’t supposed to be applied above 90F. The boat topped out at about 87 on the project day, we were safe, but we did have to contend with the shortest possible pot life. Even starting in the morning when it was a few degrees cooler, we found pot life was rarely as long as thirty minutes. And because it’s solvent-free epoxy, mixing well is especially critical, and eats up the first three minutes. So we mixed small batches, and painted it on with a sense of urgency, and it all somehow worked out OK. The three quarts of material managed to cover the whole tank on day one, with enough left over to touch up all the spots we missed, and re-coat most of the larger surfaces, on day two. And, because Jazz did a great job prepping the blast area (and her hair), we managed to avoid having any unintended white spots. Success!
With the tanks painted, we turned to the water hoses. Our friends Colin and Charlie muled us some new hose (more on their visit later), and since the new was just a drop-in replacement, we were able to replace each section by duct-taping the new hose to the end and pulling the old out from the other side. Easy-peasy! The hardest part? Dealing with the confined spaces, like behind the water heater where a rogue hose collar got caught on a rogue restraint. Gloves are also a must, to protect the hands from treacherous zip ties. And we tried our best to avoid spilling the gross water that was left over in the pipes.
I expected it to be a little gross, but I was still surprised at just how gross, given that we’d been running all the water through a filter for the past six months before it even got into these pipes, and pumping bleach through every so often. Some of the gunk wiped off, but you can see in the last picture that there was a whole layer of white buildup on the formerly-clear vinyl. The lesson? Water pipes are not self cleaning. On a related note, I was amused to see that the kitchen faucet fittings color-coded themselves, as the vinyl colorant bled into the brass.
Of course, no project is done until it’s tested, so once the new hoses were all collared up, we slipped an Ikea bag over the intake valve in one tank, filled it with water, and turned on the pump. The pump primed, water flowed, and we found no leaks! I am skeptical of projects that don’t somehow go wrong, so we will be monitoring the situation when we fill the tanks for real. But for now, we’re calling this one done. One more card off the fridge!