Monday, October 9, 2023

Boat Yoga and Lost Time

I took last Friday afternoon off in the hopes of wrapping up a bunch of the 'Before it gets too cold' projectts and ended up making a mess and not really getting much done.  With the rain on Saturday and family commitments on Sunday, I really only had the time to get back to were I should have been Friday afternoon.  Oh well.

My plan on Friday was to get the Airmar B60-20 depth transducer installed along with a bunch more bilge painting. The old depth transducer was something smaller than the 2-3/8" hole I needed for the new one and if you've ever had to overdrill an old hole with a holesaw, you know it can be a challenge.  I had a cool trick that I had heard about and wanted to try; just bang a piece of scrap wood into the old hole and then mark the center.  Once you have the center, you can use the pilot bit in the larger diameter holesaw to drill the center and guide the bit.  

I was really pleased that it worked really well and thought I was well on my way to getting a ton done for the day.  I dry fitted the new transducer, but didn't snug down the nut.  My son came over to help and we slathered up the transducer with 3M 4200 and fitted it in.  I started tightening the nut and it became increasingly difficult to turn with the sealant in the threads so we decided we needed to get 2 wrenches on it (one to keep it from turning in the hole and the other to tighten the nut).  Unfortunately, the location of the through hull is under the vberth, and while I can get a hand on it easily, getting 2 on is nearly impossible. There is a second opening from above and my son was able to reach down and just barely hold onto one of the wrenches while I somehow manage to get 1 arm and both my shoulders through a very small opening.  

After much grunting and lots of choice words when the wrench would slip and my knuckles would smash into jagged bulkhead corner I got it as tight as I could.  To my horror though, I could still wiggle the transducer in the hole and there was a noticeable gap in the center.  So, when I decided I didn't need to snug down the nut when test fitting without sealant, I didn't notice that there was a slight curve to the hull there and it was not flat, so no matter how tight I got it, it would never seal properly. Uggh.

So we reversed the procedure complete with lots more choice words directed at all manner of things and pulled the transducer.  At that point we were 3 hours into the job and decided that it was time to cut our losses and call it a day.  We went home and I spent the night cleaning the transducer threads with a toothpick and a wire brush. What a fun Friday night!

Over the course of the weekend, I came up with a solution and once again, a donut came to the rescue (is there anything they can't do?).  This particular donut was a 1/2" G10 plate that I drilled a 2-3/8" hole and shaped to match the interior of the hull.  There was a lot of test fits before I was satisfied that it sit perfectly flat on the curve of the hull.  Then I test fitted the tranducer and was able to snug the nut down very tight with no gaps.  I epoxied the donut to the hull and let it cure overnight. When I came back in the morning, I was able to give it a quick sand to clean up any little globs and then refit the tranducer just to make sure.  Finally, we re-bedded it with another round of 3M 4200 and it snugged down perfectly with very little effort.  A lot of effort for one through hull, but I'm now certain it is very secure and will not give me any trouble in the future.

Mmmmm, donut

Finally a snug dry fit

The finished product

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