tranducer holes

[windrose]

Any tips on filling the holes the old transducers came out of.... I was thinking glass cloth on the inside of the hull, then filling the hole with "kitty hair" sanding and fairing with gel coat filler for the one I plan to fill.

The other is in the wet locker and will be where the eye for the depth sounder will be located. I need to install it and build the hull out around it so it will be level. Any tips on what to use for this/ tips on the actual process and getting the transducer level, etc. Thanks.

[bcooke]

I was thinking glass cloth on the inside of the hull, then filling the hole with "kitty hair" sanding and fairing with gel coat filler for the one I plan to fill.

That should work. I filled all my old thru-hull holes by layering in cloth but I did it more just to try out the technique than out of any need. The layering method didn't come out quite like the "textbook" pictures but it makes a pretty strong repair.

While grinding away, I came across an old 2" thru-hull hole that had just been filled with cabosil or something and it seems to have held up fine. No reason not to go that route. We are both talking Tritons here right? Plenty of hull thickness to bond to.

"Kitty hair"? That doesn't sound like cabosil :-)

If you are filling below the waterline I don't see why you would need or want the gelcoat filler. The epoxy in the repair is a better barrier than gelcoat could ever be and it will all be painted. I would go with a fairing filler (e.g. WEST 407) to fair the hull and to make it easy on yourself.

-Britton

[Tim]

Filling old through hulls is easy. I usually put masking tape over the outside of the hole and fill it from inside with a thickened epoxy mixture. When this cures, I grind a slight depression in the outside of the hull (dish-shaped) and stick in a couple small overlapping layers of fiberglass. When that cures, I sand it flush and fill as necessary to smooth the area.

Here is a more complete description with pictures:

http://www.thedaysailor.com/rebuilding/hull2.htm

[windrose]

Thanks. Got it.

[Figment]

The other is in the wet locker and will be where the eye for the depth sounder will be located. I need to install it and build the hull out around it so it will be level. Any tips on what to use for this/ tips on the actual process and getting the transducer level, etc. Thanks.

I just went through this a few weeks ago on a buddy's boat.
We used a bevel and a level to get a rough idea of the angle required, and ripped a 18" hunk of mahogany (built-up of several scraps) to that angle. We fine-tuned the bevel, then cut the 18" piece into 12" (outside) and 6" (inside) sections.
We drilled a small hole through the hull at the desired transducer location, and through this hole we temporarily held the outside block to the hull for some rough-fairing with an angle grinder.
The block was then removed, faired smooth, and coated in clear epoxy.
With thickened epoxy, we adhered the block to the hull (held by that same screw) and filleted the edges. After this epoxy had cured sufficiently, the screw was removed and the inner block was epoxied in place.
Only then did we pick up the hole saw. Of course, the hole saw didn't have sufficient depth to cut in one pass, so we cut as deeply as we could, cleaned out some scrap with a chisel, and finished with a second pass.

In the end, the finished product was a not-terribly-noticeable lump in the hull. The funny part came the following week when someone else was helping with the bottom paint and REALLY didn't notice the lump and painted right over the brandy-new transducer.

[windrose]

Duh! After all that.

I buggered up the one in the wet locker a bit getting the old (non working) unit out. Do you think I should totally patch it and then redrill it, that is what I am thinking. I was thinking of using the same hole and a good backing plate. However, now I am wondering if I should move it over a bit, where the hull has it's full integrity, and patch up the existing hole.... see why I hate spending time in traffic, the mind has time to ramble. Suggestions?

[Figment]

Depends on how badly you buggered it!

Have you found yourself in the rare position of replacing a unit with another of exactly the same size? I've heard tell of such things, though it's never happened to me personally.

How big is this hole? if it's just two inches or so, I wouldn't worry much about hull integrity. Just patch it a bit and keep going. If this is the one that needs inner and outer blocks for leveling purposes, don't even bother with the patching, as the blocks should remedy the sins of removal.

[windrose]

2" or so and I buggered the gel coat and dug a little into the glass, that's all. Yes, it is where I will have to level the unit. It seems the best spot to put a depth sounder.