7 years ago my late husband and I took our boat out to replace and fix things. He passed away a few months after taking it out. So now I'm finishing it. Slowly.
I'm replacing all of my thru-hull fittings and need to know where I can find info on the exact specs for sizes and shapes I need? I know they are 1" dia.
I guess we threw the old ones out.
My boat is a 1993 36 hull #1224
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Spanki & {Russ 12-8-1949/9-6-2010 R.I.P Butch}
s/v Spanki 1993 Catalina 36 #1224
"Don't worry, Be happy""Sail your life away"
Sorry about your husband.
Maybe the easy approach would be to take some dimensions- hull hole diameter, thickness of hull in that area and associated hose inner diameter. Take those measurements to a marine store like West Marine or a local marine supply house and work with them. Also describe the purpose of each thru hull to make sure you get the right material. You can go all stainless or bronze if price is no object. Dry fit the thru hulls as a final check before caulking them in place with the nut flanges. It helps to have someone on the outside of the boat to prevent the thru hull from spinning as you torque the nut flange. Bed them in polysulfide caulking -especially the ones below the water line. Do not use silicone. Use new hose clamps and double them up for the locations below the water line. For areas using two hose clamps, make sure the clamp screws are on opposite sides of each other. This will make for a more secure hose attachment and more uniform stress on the thru hull neck (nipple). It's not a bad idea to recheck the clamp screws after a few days to make sure they are snug.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
I checked the ID hole size of my head thru holes. I used a 1" and a 3/4" hole saw. One is a 1" cut out. But the other is between a 1" and 3/4" size.
I haven't found a thru hull fitting that's an in between size so the 3/4" fitting is what I use right?
The photo is of the two head they holes. The top is the 1" ID. Bottom is the odd ID size.
Spanki & {Russ 12-8-1949/9-6-2010 R.I.P Butch}
s/v Spanki 1993 Catalina 36 #1224
"Don't worry, Be happy""Sail your life away"
I'm not sure why you are using a hole saw? You shouldn't need one. To remove the old thru hulls, remove the hoses/clamps, unscrew the flange nut on the inside of the hull and push on the nipple (hose barb) to free it from the boat hull. Be sure that it is clear of bottom paint (which may act as an adhesive). Also, you might need a large adjustable wrench or pipe wrench to loosen the flange nut. The thru hull will probably be bedded in adhesive and you may have to rock it back and forth to break the bond from the hull. Be sure to remove all the old adhesive before bedding the new thru hull in poly sulfide sealant. You can take the old thru hulls to the marine supply store to size for new ones. If you have used a hole saw to remove them, be sure that you have not enlarged the holes in the fiberglass hull. That may create a need for a whole new solution. Is there any boat yard worker that can help you?
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
All fittings are already out. Did a total bottom job and replacing all fittings. I used the hole saws to measure the ID size to make sure of the correct size for new thru hole fittings.
I posted a pic of the head they holes on here. Hope it can be seen.
Spanki & {Russ 12-8-1949/9-6-2010 R.I.P Butch}
s/v Spanki 1993 Catalina 36 #1224
"Don't worry, Be happy""Sail your life away"
Spanki-
Glad you were just using the hole saws to measure, not drill. Good luck finding the replacements; you may have to rely on more than one marine supply to find the right ones.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
Good chance they were Forespar flush-mount thru-hulls. A 1" hole is usually drilled for a 3/4" thru-hull and that is a common size for all head / sink / shower usages, corresponding to the usual size of the seacock inside the hull. I'm surprised there are two different sizes holes as this suggests there are two different size seacocks. Perplexing. The smaller one suggests a 1/2" thru hull. Can you tell if you have two different size seacocks on the inside of the hull?
Nick Caballero
Retired C36/375IA Mk II Technical Editor