Tuesday, April 27, 2010

Thru-hulls

My new work situation, that of being semi retired has allowed me to get in some quality time in on the boat.

The bottom is now 100% painted, even the spots where the stands were. The boot stripe got it’s final coat yesterday. Now the tape is off, the boat is really looking nice. Getting the waterline on really makes the topsides look sleeker.


I’ve been slowly knocking out the thru-hull upgrade. The boat came to me with ball valves screwed onto the thru-hulls. While this seemed to work fine for the last 30 years, I wanted to make sure they were as bullet proof as possible. Most of the ball valves were heavily corroded and took some serious leverage to open/ close. This created some noticeable flex at the base of the valve/ hull.

Due to time and money, both lacking. I chose to make my backing plates out of white oak. I’ve used it for exterior bits before on the Westerly’s companionway. I know it holds up to the environment fine. It’s also cheap, and easy enough to cut/ drill.

Originally I planned to have a single block, but once I looked into it closer, the hull has this sort of nipple due to the thru-hulls being flush mounted. So, I ended up making a second block, ½ as thick and making the center much larger. I used the grinder and the flap disc to form the back side of the block to fit to the nipple. Adding a single layer of mat when each was epoxied to the hull, along with epoxy thickened with 406 filler made sure each thin plate was sealed on the backside and had a good surface area to bond.



Once the first plate had cured I put the bolts in through the backside of the main block. When I counter sunk the blocks the counter sink was just a hair smaller than the bolt head which turns out to work really well. By threading the nut down the bolt was pulled into the counter sink and locked into place.



Now working with wet epoxy and thru-hulls is not the best one person job. Lacking a personal assistant, I had to make it work. 1st off, doing the main block after the thin one had cured made the job simpler. I tried to do both blocks once and it was a stressful endeavor. Thankfully I got another guy in the yard to come over and start the thru-hull while I held the mess in place.

So after the thin block was cured, and the bolts in the thick blocks I would insert a thru hull from the outside. The thru hulls are too long and will need to be cut, but I wanted to wait until all the blocks are in for fear of cutting them too short. The thru-hulls being too long meant I could steady the thru-hull with a finger while threading the thick backing plate/ seacock/ 406 thickened epoxy combo on a few threads. Using any means necessary to steady the seacock I would climb out of the boat and give the thru-hull a few more turns from the outside, hopefully until it bottoms out. Then, back into the boat and I would begin to unthread the nuts. (I skipped telling you I threaded in the nuts, then slipped the thru hull over the top) by unthreading the nuts equally the thru-hull pulls against the hull and compresses the thick block into the thin one. I let that cure over night and the next day I have one hell of a solid base for the seacock.



The head inlet was a bit trickier. The hull liner made is so there was a 1 1/2” gap between the hull and the liner. I opted to cut the liner out so I could install the plates like I have been. Once the plates are in place I can add a filet of thickened epoxy and then the entire sole can get a coat of paint. I cut the liner, (more like drilled it) today. I got the thin plate in place, but missed taking a photo.





























The next step is to epoxy the hole, so if the thru-hull leaks a bit, the water won’t soak into the oak. One good coat should do. Then each block will be coated in some Pettit 4700/4701, which is their epoxy barrier coat. I’ll use this simply because I have some left over. The bilge will get a good coat too.

I’ve begun to read more on the Atomic 4 and am creating a mental check list on how to put some things back together (prop, shaft, coupler). I need to re-wire it, install a battery, hook up the throttle and shift cables. A good tune up would be nice, plugs, oil, filters. Then there is the whole exhaust thing. There is the stock standpipe and a water lift. I don’t know enough yet, but if anyone has knowledge of either system they want to share feel free. Better yet, come on down to the boat and I’ll feed you beer!

I brief update. Boat should be in the water in a few weeks. Not sure where she’ll be moored just yet, someplace with direct access to the sound and cheap.