Forward fish box drain (Update)

[erebus]

Originally Posted by CHANCE1234

I was thinking of drilling it out a little bigger than a fiberglass tube from McMaster Carr. Then insert the fiberglass tube and ensure it is flush with the bottom of the hull by placing a board and support under it to hold it in place then inject west system with a syringe around the entire tube from the inside to bond it in place. Remove bottom support, insert plug and go. Any issues with this plan

That's pretty close to how I did the fwd drain on my 18SF.
Only difference is I slid it in flush(ish) with the inside of the fish box and let it hang long on the outside.
When it was all kicked off I just sanded it flat, primed and painted.

Also I drilled my hole pretty close to the size of the fiberglass tube, and sanded a small chamfer on the hull side of the hole.
I filled the void between hull and fishbox with thickened resin, sanded and resined up the tube and slid it home.
Troweled a little epoxy into the chamfer and then like I said earlier, sanded it all flat.
Two seasons, no leaks or cracks.

[CHANCE1234]

Oldfielder what did you use for a low profile threaded thru hull? Thank you

[oldfielder]

Pretty sure it was a 3/4 bronze mushroom. I dry fit it, measured and marked the threads and then cut it down with a hacksaw. Two man job to install. One guy holding the nut on the inside and one guy turning it with a step wrench on the outside. Pretty sure I sealed it with 5200. If I were you I would drill the hole and then fill the void around the hole with peanut butter. Let that set up and then use above method. This way when you go to install thru hull you won't compress the space.
http://www.perko.com/catalog/underwa...use_with_pipe/

[CHANCE1234]

Zac, explain to me what a chamfer is/does. Thanks

[erebus]

Just kind of sanded the outside of the hole (hull side) with a slight angle all the way around, instead of a squared off hole. Just a way to get more epoxy around the frp tube and bond it to more of the hull.
Same way you'd grind back a hull repair, but not so extreme.

I replaced the forward fish box drain on my buddies 23 seacraft with an FRP tube as well, but in his instance I did grind back the hull just as if I was doing a hull repair, and laid glass over the opening after I epoxied in the FRP tube. Then re-drilled it from the inside.
He likes to pound the crap out of the boat, so I thought a little more hull integrity couldnt hurt.

You just painted your hull didn't you? Might have to take the simpler approach to avoid having to repaint a section.

[CHANCE1234]

Ok, so I went with the simplest attack and decided to just put a new brass drain tube back in. I drilled the hole with a one inch hole saw and this is what I find...





If you can't tell from the pictures there is a large void on the aft side of the hole between the hull and liner, I can stick my finger as far back as I can reach.

What the hell do I do now?

[CHANCE1234]

Before I do that, do you think it would be a good idea to put some cabosil in the void by using my finger so it has something to stick too and so I don't just keep pushing all that stuff aft when it gets into that void via the plungers?

[FLexpat]

Originally Posted by CHANCE1234

Before I do that, do you think it would be a good idea to put some cabosil in the void by using my finger so it has something to stick too and so I don't just keep pushing all that stuff aft when it gets into that void via the plungers?

Probably a good idea but you want to get it back in a good bit in all directions

[CHANCE1234]

I heavy some west system thickened epoxy already in the tubes that says to just mix 1:1. I forget the number of the system but do you think that would work. It's sags very little if at all

[FLexpat]

probably fine - if you have milled glass fiber it would be a bit stronger.