Wet Core

Jul 23, 2013
20
Hunter 37
Help!

I have a two day weather window to replace a Gray Enterprises port light on a Hunter 37, Cherubini cutter, 1980 -- today and tomorrow. Today I was able to get the old leaky one out but I found the plywood core was soaked on the aft bottom and side of the opening.

So now what!?!? I've got water proof (plastic base) masking tape covering the opening for tonight, but I don't want to trap the moisture in by installing the Gray port tomorrow! I can't leave the tape all winter, it won't last.

Any thought or comments would be appreciated.
 
Oct 22, 2014
16,418
CAL 35 Cruiser moored EVERETT WA
Here is just a swag.. No images.
You can try to run a vacuum on the affected area. Not sure you can get a good enough seal but bagging the area and attaching a shopvac in under the plastic might create enough of a vacuum to reduce the moisture content in the plywood. You can also put a heat lamp on the area as well to try and dry out the wood. Not sure anything will work in a 24 hour period. It might be possible to tent the area and give your self more time before you try to insert the window. Sometimes time is not our friend.
 
Nov 6, 2006
9,247
Hunter 34 Mandeville Louisiana
If the wood is rotted, gouge it out and replace .. If it is wet, and in reasonable condition, you can use a hair dryer to tease the water out before replacing the port.. It is best to not put sealant on the inside.. the seal should be on the outside, between the port snout and the cabin side and the trim ring.. That way, when you do have a leak you know that the outer seal has failed, and you want to address it before it has a chance to rot the core. the sealant that Gray wants you to use requires moisture to cure.. Let it sit open (with a plastic cover over the hole) so that the inside breathes the water out.. If ya get a lot of sun and the temp is fairly high, it will get reasonably dry in a week or so..
 
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Jan 1, 2006
6,166
Slickcraft 26 Greenport, NY
Acetone. I defer to our Chemistry professor but we used to use it to dry everything in Chem. class. I would do all of the above and then douse with acetone generously - several times.
I don't see why it can't be temporary covered for several months to allow complete drying. A seal on the hull and a dehumidifier inside could work.
 
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Jan 22, 2008
1,595
Hunter 34 Alameda CA
Unfortunately the proper approach is to tape it off on the outside and get that core dry. Really dry. Otherwise you can get rot. That could be from a fungus that can march through the wet wood. This just happened to me this season and I ended up hogging all of the wet (and decomposed wood) out. The core was made of individual pieces. It turned out the rotten stuff was isolated to a single piece. I dug it out about 4 inches down inside until I found the next piece that was solid but wet. Same for the adjacent piece which was wet but solid. I let it dry for a month during the summer. The last 2 hours I used a hair dryer to blow hot air in the the gap between the fiberglass skins. I injected a couple of syringe loads of Git Rot down inside where the original, but now dry wood was just to be sure it was sound. That has the viscosity of water so it wicked up as near as I could tell. Then I re-framed the opening first with new wood and used cedar shims to make sure there was no gap between the skins. All of that exposed wood was saturated with West epoxy. Since the plywood Hunter used had voids, I then mixed thickened epoxy and troweled it into the gaps, and filleted the corners. This formed a solid bridge between the outside skin and the inside skin. Now if it leaks it will not go between the layers, but rather "leak to daylight". I'll see it come inside and can address re-caulking the port light if necessary. Luckily, none of the other 7 port lights I changed had damaged wood. They all had the separation of the inner skin from the core so the potential was there to allow leaks to go unseen and cause real structural problems like the one I found. As I was replacing all the other port lights I was coating the bare wood with epoxy and filling the gap with additional wood.
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Sep 25, 2008
6,355
Alden 50 Sarasota, Florida
Acetone. I defer to our Chemistry professor but we used to use it to dry everything in Chem. class. I would do all of the above and then douse with acetone generously - several times.
I don't see why it can't be temporary covered for several months to allow complete drying. A seal on the hull and a dehumidifier inside could work.
Acetone is soluble in water. I've heard that suggestion before but unfortunately it's a myth.

There is no easy fix to this problem other than prolonged drying.
 
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Jul 23, 2013
20
Hunter 37
Thank you to everyone who replied!

I could leave it open for the winter... Any suggestions on how to keep the weather out? If I leave it taped up the masking tape will degrade and fail and leave a nasty residue. Duct tape would be even worse.

Thinking of making a plywood cover and gluing it with 795 against the weather for the winter. The silicone should come of cleanly in the spring??? I'd brace it from the inside so it's open and dries. Does this sound realistic?
 
Jan 22, 2008
1,595
Hunter 34 Alameda CA
You can tape a piece of plastic so that it can fold back down over the tape shielding it from the environment. Then it can drape over the opening. The bottom could be weighted down with something like a sand bag.

Or a piece of plywood to cover the hole. Then put a long bolt through it and through a piece of 1 x 2 that you can rotate to the short direction of the opening. Tighten a nut on the bolt and it will snug the plywood to the outside.
 
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Jan 21, 2009
232
Catalina 30 Lake Perry, KS
Use Gorilla waterproof tape. It is clear and not hard to remove later. Great temporary seal. Just cover the hole and tape the perimeter. You could probably get away with a cut up milk jug to cover the hole.
 
Oct 6, 2007
775
Hunter H30c 1982 Chicago IL
Tape heavy plastic sheet over the outside with shrink-wrap tape. Leave it open on the inside. Put a few DampRid buckets in the cabin and let the core dry out over the winter. It may speed the drying if you can run a small fan in the cabin.

If the wood is rotten, dig out as much of that as you can now. You want to expose good, solid wood and let that dry for as long as possible. Then fill the void with new wood and epoxy in the spring. If you can’t quite get at all of the rotten wood out, but can get it dry, penetrating epoxy is a good option.

I used this process a few years ago when I replaced all of my portlites, though I had the luxury of doing it with the boat shrink-wrapped, so I had less concern about keeping the weather out and I had good air circulation with the shrink-wrap vents.

One more suggestion: In the spring when the core is dry, brush on some epoxy to seal it before installing the new portlites. You want the core protected against future leaks.
 
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Feb 26, 2004
22,015
Catalina 34 224 Maple Bay, BC, Canada
I covered a port like that with a cut up plastic bag and blue masking tape. Lasted all winter.
Other ideas much better but mine worked.
Good luck.
 
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Jul 23, 2013
20
Hunter 37
The core is sound and I'm trying to save it.

Loaded some plywood in the car. Headed off to check out Guerilla tape, DampRid, etc...

So many thanks to all of you. GOOD STUFF!!!!
 
Apr 5, 2009
1,655
Catalina '88 C30 tr/bs Oak Harbor, WA
Use preservation tape to attach a sheet of heavy plastic over the hole and finish in the spring. https://www.jondon.com/preservation-tape-various-sizes.html.html
It is waterproof and will last all winter and leave no residue. I often take my handrails and other teak home for the winter to refinish. I put a small square over each hole and it never comes off until I remove it in the spring with no sticky mess underneath.
 

Alctel

.
Dec 13, 2013
263
Hunter 36 Victoria
Use Gorilla waterproof tape. It is clear and not hard to remove later. Great temporary seal. Just cover the hole and tape the perimeter. You could probably get away with a cut up milk jug to cover the hole.
I did this and it worked well. Make sure to tape up starting at the bottom so water doesn't get through the seams.
 
Jun 5, 2010
1,080
Hunter 25 Burlington NJ
I have a suggestion that, weirdly, doesn't seem to have come up yet here. That is: shrink-wrap the whole boat. Shrinkwrap is marvelous for a wounded/unfinished boat. If it's one thing that will seriously extend your boat-work season, it's shrink-wrap. You will turn that thing into such a greenhouse that you'll be able to work in shirtsleeves inside it for the whole winter. I've done it; no problems.

In my area a decent professional job will run about $400. I save by pre-rigging the boat (this year, putting the mast on top like a ridgepole) and having a 'friend' (former customer) just wrap it and heat it. About $200-250, especially if I buy his beer and steak sandwich for after.

The best thing about living in the 'bubble' is that you can run a standard household dehumidifer in there. Believe me, with a good solid shrink-wrap job, and judicious placement of DampRid cups, you will have that place bone dry.

I definitely do not advise leaving the boat in any climate noted for snowfall, cold rain, freezing conditions, hard wind, falling twigs and leaves, or vandals with just a piece of plastic taped over a hole. That would keep me up most nights all winter.

Also, I would not worry too much about the rotten core you see now. Seal that boat up, run a dehumidifer inside whenever you are there (hopefully often; though never when you're not), and gradually chip away at the mess till you have a nice dry (probably deep) pocket to work with. Then, do what Allan did. :dancing: