Head Trouble

[HopCar]

Here is a link to a blog where a fellow has done a very nice job of installings Groco IBVF flanges and valves: Far Reach Voyages.Com

Go to the Groco website: www.groco.net Click on "Products" then "Seacocks and Ball Valves" then click on the picture of the IBVF. This will show you the sizes available.

We are just bringing in the IBVF. It looks like the IBVF-750 (3/4") will sell for $24.95 and the IBVF-1500 (1-1/2") will sell for $39.95. These are the two sizes commonly used for a toilet installation.

[HopCar]

Hi DeepFrz, I hear that a lot about 5200 but I use it below the waterline every time. It's especially good for installing thru-hull fittings. It's very easy to break metal loose from 5200. Just warm the metal with a propane torch and it will pop right off. There are several solvents that are designed to remove 5200 as well. BoatLife makes one: BoatLIFE | Release Adhesive & Sealant Remover 1oz. - Solvents & Removers
Another is called DeBond: Marine Formula by DeBond Neither make it easy to remove 5200 but they do make it possible.

[DeepFrz]

I still think that 3m-4200 (or equivalent) is a far superior product for this situation. It seals, has some adhesion and allows you or the next owner to remove the part when necessary.

[HopCar]

Nothing wrong with 4200.