Glassing in thru-hulls: project report

[Beersmith]

As part of my long restoration, I had a couple of thru-hulls that needed glassing in. One was for the holding tank discharge, the other wasn’t used at all (no hoses on the seacock). I will be going with a composting head, so the holding tank discharge was unnecessary. Many people seem to think that glassing in a thru-hull is “too big” of a project, but I found it to be one of the easier jobs during this whole restoration. Granted, I’ve filled in a few other thru-hulls, but these are my first below-the-waterline holes.

By following good fiberglass/epoxy procedures, the process was pretty painless. The worst part about it was grinding the huge bevel for a proper job. It took about 25-30 minutes of careful grinding to get the correct shape using a flap disk. I ended up with about a 10:1 bevel, and about 12 layers of bi-axial glass. With careful cutting of the glass disks, I was able to shape the repair pretty flush with the hull. Of course, it will need some grinding and fairing, but overall I am very satisfied with the repair.

Thru-hulls in question:



After grinding:



All glassed in:





size reference:

[unbusted67]

Nice job. What size holes are those? It's a little tough to gauge.

[Beersmith]

Originally Posted by unbusted67

Nice job. What size holes are those? It's a little tough to gauge.

one is 3/4", the other is 1-1/2".

[Matt Johnson]

I have an old depth transducer to fill in too. Unfortunately, I have 6 months before it's warm enough in Michigan to do any glassing.

The old transducer was debbed in 5200... I think it was harder to remove them then it will be to fill the hole in.