I've found 2 of the thru-hulls on my Morgan 321 and I know they need replacing. They look like originally installed and don't trust them despite the surveyor saying they were adequate. The ball valves move freely, it's way they are attached that really bothers me. The problem is they are buried in a pile of fiberglass and not sure how I am going to attack them.
Part 1:
My original thought was to use an oscillating tool and to cut away the pile of fiberglass and then see what I have. From the outside, there is no mushroom head so I don't know how it is attached to the hull. I thought I had seen a posting on one of the sailing forums with a similar installation but now I can't find it.
Part 2:
I know I'm going to have to sand away the bottom paint and guessing I'll need to bevel grind around the outside of the hole and re-laminate the hull to provide a good surface to seat the mushroom head. I'll probably need to so something internally also for the backing plate.
Here's a couple pictures:
Q1: I've never used an oscillating tool before. What kind of blade(s) should I be looking for or do you have suggestions for another method?
Q2: Do I need to grind away on the outside of the hull and, if so, what type of fiberglass cloth(s) should I use to rebuild the laminate? Once that's done, should I use some epoxy fairing compound around the repair? I'm planning to strip and bottom paint the hull once I've got these fixed.
I plan on using Groco bronze thru-hulls from MaineSail's recommendations along with some G-10 backing plates. I've read his articles a few times and looked around the web/YouTube for other articles about this but the search results are overwhelming. Any other links would help.
ETA: Does anyone in the Oswego, NY area have a Groco installation tool (THT-530) that I could rent, buy or borrow when the time comes?
Part 1:
My original thought was to use an oscillating tool and to cut away the pile of fiberglass and then see what I have. From the outside, there is no mushroom head so I don't know how it is attached to the hull. I thought I had seen a posting on one of the sailing forums with a similar installation but now I can't find it.
Part 2:
I know I'm going to have to sand away the bottom paint and guessing I'll need to bevel grind around the outside of the hole and re-laminate the hull to provide a good surface to seat the mushroom head. I'll probably need to so something internally also for the backing plate.
Here's a couple pictures:
Q1: I've never used an oscillating tool before. What kind of blade(s) should I be looking for or do you have suggestions for another method?
Q2: Do I need to grind away on the outside of the hull and, if so, what type of fiberglass cloth(s) should I use to rebuild the laminate? Once that's done, should I use some epoxy fairing compound around the repair? I'm planning to strip and bottom paint the hull once I've got these fixed.
I plan on using Groco bronze thru-hulls from MaineSail's recommendations along with some G-10 backing plates. I've read his articles a few times and looked around the web/YouTube for other articles about this but the search results are overwhelming. Any other links would help.
ETA: Does anyone in the Oswego, NY area have a Groco installation tool (THT-530) that I could rent, buy or borrow when the time comes?
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