Adding Tomcat Thru-Hull for Washdown

thataway":2ucnmsrz said:
4 layers should be great! It looks as if you have had water intrusion from both window frames and the anchor locker. I have seen water migrate some distance from a leak--fortunately most of the windows in our boats are not into cored material- only the aft cabin bulkheads

Hey Bob I bought one of those fancy nondestructive moisture meters so I can track the water intrusion sources pretty easily.
That rear bulkhead with the door all water came up from where it attached to the floor. We had resealed that attach point over and over, but at times water would come in from the rear deck into the cabin underneath and balsa we couldn’t see was exposed. It is dry near the windows.
You are spot on for the anchor line locker source. I previously paid somebody to go into the anchor locker to dig out the wet core there. The water was coming from the drain hole and and winch eye. The part I’m working on now is where the water wicked further down below into the tunnel and then froze in winter and popped through the glass inside.
So far all of the interior laminate seems to be 1/8“, two layers of 1708, which I believe counts as four, layers gets me the same thickness.

If I had a new tomcat, (hint, hint) I would pull the winch point, remove the anchor drain clamshell cover and do the epoxy re-bed on all core intrusions in this area! Some of that core was so wet and rotten it wasn’t even attached to the laminate anymore.

I hadn’t mentioned previously, but we already had to replace ALL the bottom core bow to stern in both sides. Yes, even under the head. $25,000 for that job. That’s a bigger story than I have time for now😀
 
1708( Stitched roving bundles @ 45*) is used instead of the old 18 oz woven roving at 90*. Properly used it is stronger for the same weight. We used to use 24oz woven roving with layers of mat between and over/under.

I am a little surprised at only 1/8" thick on bottom and top of the bottom of the hull, I would have liked to see about 1/4" thick on the bottom, and then the 1/8" on the inside. The 1/8 x core x 1/8 is stiff enough (if nothing breaks down, but there is considerably less impact resistance.

Amazing with the entire bottom--screw holes from fastening tanks and bilge pumps??? freezings and thaw cycles are deadly for a cored boat once it has water intrusion into the core.

Had you fully pulled the door, and then made an epoxy/fiberglass barrier under the sill? Again, I think that the freeze thaw cycles force the Delam,and then more moisture up the side of the aft bulkhead.

I agree with your assessment of the anchor locker/bow eye. These areas should have been solid laminate to begin with.

Have you been climbing down into the hulls? A fat man could not do that! I am not even sure I could (not really skinny any more, but at "ideal weight").

Thanks for the insights into the serious issues, you have solved!
 
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