How much water in the blge is "normal"? - Page 3

Briguy · #21 01-22-2009, 01:15 AM

Quote:

Generaly what has happened with these thru hull fitting is time failure. The early years they used a brass ferrul tube then replaced with a plastic screw type fitting. Either one will take it's toll after years of hull flex and pounding.

I called Mike @ Wildfire and got some pointers.
Don't let all this "long how to post" crap below scare you. It's really no big deal.
First you need to take a screw driver or chisel and knockoff the outside lip and then from the inside of the piece you can crack it and drive it out. During construction they used some sort of bonding putty like on the baitwell to transom adheasive between the outer hull and inner liner. Over time this putty material breaks off in chunks leaving a gap that water now has a path to the bilge. Even the brass ones will lose their putty and sealant outside around the small flange. You can push on the hull outside next to the thru hull and sometimes see the space.

You need to refill this gap between the inner liner & hull again with some type of heavy putty before putting in your new thru hull fitting. It might take you a few layers at a time jammed in there to avoid the putty dripping or falling down within. Check all around to make sure the gap is filled 360* and cured.

The standard thru hull is approx 2.5" you need to get the extra long threaded 3" or larger with a large flare and screw down nut. I used Gemlux S/S brand. Do a sample measurement with the nut tightened in position and mark the threads flush with the outside of the nut. You will need to cut it before installing. It will take two people. One to hold the ouside flange steady while the other tightens the nut inside. Use 5200.

Note: The reason you need the putty built back up between the inner liner and outside hull is that when you tighten down the two they will be drawn together. You need to maintain the gap or future pounding and flex will open it up for water intrusion once again. Since replacing mine in '04, I keep an eye on it yearly looking for signs of weakening or sealing issues.

Good Luck

OUTSIDE

INSIDE with threads cut flush with nut

This is one of the best posts I've had the pleasure of reading. I'm a candidate for doing this repair for sure!!!!!!!

1Step · #22 01-23-2009, 09:47 AM

Chuck, it this the one to use?

http://www.gemlux.com/pdf/launchshee...edThruHull.pdf

Capt Chuck · #23 01-23-2009, 10:28 AM

Mine was replaced in '04. Mine didn't have that ground tab. It should not make any difference. This new one appears to be the one you can use

1Step · #24 01-23-2009, 10:48 AM

Thanks Chuck. I should get the 5" and cut it down, correct?

Also, any special putty you recommend?

Capt Chuck · #25 01-23-2009, 11:39 AM

Quote:

Thanks Chuck. I should get the 5" and cut it down, correct?

Also, any special putty you recommend?

Do a test measurement first and just give yourself an extra 1/2" or so past the nut. The 1" dia should surfice.

As far as the putty material, I would make my own with resin & cabosil. If not I guess you could use "Marinetex" or Fasco "Fas-Stone"2 part epoxy compound. Either way cut up some fiberglass strands into it to make it real thick and you'll be good to go

1Step · #26 01-23-2009, 11:49 AM

Thanks Chuck.

aldo · #27 04-13-2009, 03:06 PM

Just wanted to follow up on this and thank everyone for their advice. I replaced the brass scuppers, used life-caulk on the new ones and the bilge now only pumps when it rains. It feels like I have a new boat!
The old ones had rotted around the flare under water and must have been letting a lot of water in the bilge.