Floor Delamination - small area
 

My 1975 23' Tsunami has (2) small areas just off of each side of the the i/o engine cover hinges and forward 8" or so that is delaminated. Each area is roughly 12"x12". It's obvious that the i/o hinge screws let water in - how much and what damage to the wood floor is unknown.

It's not worth doing an entire floor for.

Whats the best method to inject epoxy into the area and be sure that the entire delaminated area gets epoxy to it ?

Lastly, assuming I want to dry this area out 1st - what dpi you recommend ( short of pulling skin off ) ? Has anyone used the vacuum / evaporation idea ?

This might be a project I do in the winter, under wraps to assure that it gets done correctly.

?

On mine I'm doing the whole deck. Entourage did a partial on a 23 a while back by cutting it open on top - it looked good in the photos when he was done. Pulling a vacuum to get the water out might work but you need to get about 29" of vacuum to boil the water at room temps - not sure you could get that on the deck but moving dry air through would probably dry it some.

I had a few bad spots on my 23 deck. Last year I put it inside storage for 3 or 4 weeks and I made several holes about 1 inch in diameter. I fashioned a piece of clothes hanger by putting a short 90 degree angle on one end. I then worked with the wire and a vacuum,removing rotted wood, letting it sit for a day or two, doing it again and again. I also pulled the boat out in the hot sun for a while on several occasions.
When I got it as dry as I could, I lowered the front of the trailer to make the deck level. I poured stop rot in the holes, let it soak in, then poured again, using a wire to get air bubbles out. Let it cure and do it again. After getting close to the top and letting it cure, I topped it off with resin, sanded smooth. I wasn't sure about the different materials, but its been about a year now and its looking good and the deck feels pretty solid.

delamination - I believe what you're saying is - "dry rot"

delamination is when the glass becomes detached from the core

if the area is soft - there's no core there...

attempting to use a pour in / squeeze in product will prove less than ideal



cutting the areas where the problem is,this will prove better - provided the rest of the cockpit deck/sole is in good shape....

I had the same symptoms with my boat and decided to cut out the affected areas and try to do those areas only. But when I cut into it I found that the more I looked the worse it got. Came a point that 90% was wet and soggy wood. I did fix a small area and patched it back up just so I could get one more summer out of it, but knew that it was only temporary. Decided to do the whole floor used nida core. And I estimated that the old wet wood weighed at least 200 lbs. The hatch over the floor was at least 100 apart from the floor. Now it goes 30lbs . I imagine that the boat with all the weight off of it will run a lot better.

I am sure you did this...but take the butt end of a screwdriver handle and tap around the soft area and work your way outward til you hear a solid knock...instead of thud. You might be surprised how far out your soft spot is.

Denatured alcohol works pretty well at drying out the wood, since it will combine with the water and then evaporate.

How extensive the rot is may depend on the core. If it's plywood, the water will migrate with the grain in all directions pretty quick, so if you open it up, you may find a lot of rot. If it's end grain balsa core, water migrates much slower across the grain, so the rot may be limited to a smaller area. If it's the original deck, it may be balsa core, although my boat has plywood in the area of the seats, so they may have used plywood to handle the higher loads of the engine box hinges. Island Trader's suggestion will give you an idea of how extensive the rot is.

If the area is not real large, it's probably worth drilling a series of small (~3/16") holes in the rotted area and injecting some alcohol to try to dry it out. Once it's dry, you can inject Git-Rot in the holes to saturate the core and stiffen it. However in the area of the hinge screw holes, I'd want to drill them out (top skin only; try to avoid going through bottom layer of glass!) with maybe a 1/2-5/8" drill the then use a bent nail in a drill to remove whatever core is left over an area of a couple inches in diameter. You can then buy empty caulking gun tubes, put some thickened epoxy in 'em, and use a caulk gun to inject the mixture into the area you hallowed out. I would then drill and tap the cured epoxy for machine screws to mount the hinges; they'll hold better than tapping screws, especially if you put some blue locktite or 5200 on them!

Thx guys. I did the screwdriver test and have located what I believe to be delamination in the area mentioned. I'm sure it extends further than that to varying degrees until it's solid wood. Anybody who has worked with core knows - water intrusion does a lot of damage over time.

The soft spots have been there since I bought the boat, but this year it seems to have grown.

I'm not sure if the wood is good, mush or somewhere in between - or if the glass delam'd away from the wood. Either way, it's not structural - it just feels bad under my foot.

I'd like to try to remedy this with an easier way first - by injecting epoxy in. I want to properly dry it and then assure that the injected epoxy spreads through the entire delam'd area. If this does not remedy the issue, then obviously I have bigger fish to fry. However, the rest of the floor is solid with no softness or dull sound with the screwdriver...

When I do this, I assume I must have the boat floor level so the epoxy flows level. I could use the West System directions by drilling holes, using a hanger or allen key, clean out wet wood, dry and inject epoxy in.

As for Git Rot - I have heard of it and correct me if I'm wrong ( I'm wrong a lot ), epoxy is a better way… ?

Git Rot IS epoxy, only thinner than the West Systems stuff, so once you dry out the core it will soak up into it better. It really isn't necessary to remove the rotted core, except in the area of the hinges where you need to have screws, which should be filled with thickened epoxy.

As much as I dislike Griviskas for his superficial coverage of stuff and shameless promotion of whoever gives him free stuff, ShipShape TV did have an outfit on a couple weeks ago called Dryboat that you might be interested in. They had a big Clorox bottle shaped boat that used lots of cheap foam instead of fiberglass in the hull construction that was full of water. They drilled a bunch of drain holes along the chine and then used a vacuum system to suck the water out of it. I'm sure it's big bucks but maybe worth a look if only to convince yourself how much $ you're saving with the DIY approach! :D

I have no idea what injectable solution is best - my sponge-core is way too big for that.

That area is directly above the stringers on my 76 (also an I/O). If you pull the fuel tank hatch you can see where the stringers are forward of the engine well. If you look from the engine well you can almost see where the motorbox hinges go into the deck - you may be able to get at a little of it from the engine well.
I don't know if this will help you or not but here is how that part of the Tsunami/Sceptre is built -
Original deck schedule for early ‘70s 23’ Sceptre; top to bottom (from Feb ’73 Boating, Boat Test #207)
1 layer 3/4 oz mat
2 layers of 1 ½ oz mat
1 layer 22 oz roving
1 layer of 1 ½ oz mat
3/8” end grain balsa
1 layer of 1 ½ oz mat
1 layer of 22 oz roving
Underneath that is about 3/4" of 'Potter putty' then you get to the stringer shell which is about 1/4" thick roving. The stringers span from the inner to the outer steps; directly over the middle panel there but they have a rigging channel in them about 3" deep that might be under the outboard part of your soft area.

Good Luck - Post pics when you get into it.

Bush - thx for the heads up on Git Rot. My Dad used it here and there on his boats - but he always took the short cuts in repairs ( so I always thought it a shoddy approach ).

After this season, I will dry her out as best I can and give it a shot… Can the Git Rot be used in conjunction with injecting West System epoxy - or will it fill up the voids and harden on its own ?


Flex - That is awesome info. I have wanted something like that - and I was trying to see through old pix on the site this same area with the floor removed - to see the structure. It's odd that theses soft spots are in the identical areas on opposite sides of the i/o cover.

My boat was originally a twin I/O that I converted to a single V8 so the structure might be slightly different. I am going to pull my fuel tank hatch off to R/R my fuel sending unit within the next few days so I'll take a peak around...

I'd drill the small holes and try to dry out the core first, then inject the thickened epoxy to support the hinges, and then use the Git Rot, which is like any epoxy - it will fill voids and harden on it's own. FYI, I compared viscosity on various epoxies some time ago, and MAS epoxy was a fair amount thinner than West Systems, but I think Git Rot is even thinner - it's about like water! I think the thinner stuff is better if you want to waterproof some wood. I used MAS epoxy to seal the 1/4" layers of plywood I used to reinforce my front deck when I installed the anchor bracket and it seemed to soak in pretty well.

The only downside to using the Git Rot I can see is that if you ever decided to redo the whole deck later, it might be much harder with Git Rot in some of it, whereas now you might just be able to cut through the top skin and lift it off IF the whole core is wet. Unless the whole deck is soft however, I think using the Git Rot makes a lot of sense. Here's my experience with it:

Shortly after I got my boat in 1975, I learned that the 4" diameter plastic cup at the waterline that was the under-seat livewell inlet/outlet fitting was a potential transom killer, so I inspected it. It was leaking and there was a small area of rot around it. I dried it out with alcohol and a heat lamp, dug out the rot, soaked the wood with Git Rot, filled in the rotted area with Marine Tex, and replaced the fitting with PVC end cap, all sealed with epoxy. When Don Herman filled in the transom and installed his bracket about 30 years later, he said it was the driest transom he had ever seen in a 1972 vintage boat, so that fix obviously worked!