Repairs and upgrades for Hammerhead

[clayhubler]

I am starting a new thread for my repair.

Old thread: http://www.c-brats.com/viewtopic.php?t=29118

I have decided that because the damage is so extensive, and the boat needs repair in areas that are unrelated to the gas tank problem, I will document the work I am doing on a new thread.

At this time, I have not cut anymore of the inner skin from the cockpit. Here is what the cockpit looks like now:

I am currently waiting for a pinless moisture meter to arrive, so I can lay out a grid on the deck.

I was concerned about the hull deflecting where the boat was sitting on its bunks, even with the plywood that I put under the boat to spread the load. I have taken the boat off its trailer and supported it on blocks with support under the chines on the sides of the hull. Please advise on this setup:

 

[clayhubler]

Still waiting for the moisture meter to arrive...
In the mean time I finished removing all of the interior cabinets and seating. Electrical, plumbing, controls, everything is out.

The raw water thru-hull was sealed up much better than I thought. I don't believe it was leaking there, though the coring that is visible in the hole is wet. I think the coring is just wet all over. The bottom skin appears to be approximately 1/4" thick.

 

[clayhubler]

I don't think that I have any delamination in the boat hull. There are no soft spots anywhere and even in the back where the damage was the worst the glass and balsa was very difficult to remove. I plan to cut a little more out on the port side of the cockpit until I am getting good solid wood. This will probably mean removing most of the inner skin and balsa to nearly the cabin bulkhead, but I really don't want to go under that bulkhead. If I can get to the point where I am only removing wet wood and not rotten wood, then that is how far I will take it for now. I think the water has migrated throughout the coring through kerfs in the balsa. All the way to the front of the cabin perhaps. I also think the balsa has the tendency to wick or draw in moisture if it is exposed to it.

At this time my plans are to grid out the moisture readings once the meter arrives. If there are areas that are really bad, I will cut to inspect the coring. Otherwise, I plan to attempt to dry out the core. I plan to lay out a grid of holes on the inner skin to allow moisture to leave the core. I have a 240v heater with a fan and I've made a stand so that the heater points down at the floor. I've also ordered a dehumidifier to place in the cabin.

Next I plan to cut into the v-berth to inspect/ remove foam. I can see that the foam under the porta-potti alcove is very wet and saturated and the thin coring there is also wet.

 

[thataway]

Huge project! Thanks for the updates! Your doing a great job.

When the thru hull, is installed it should always be into a solid part (not cored) of the hull. In this case the installer should have drilled the hole, then cut out the core, and put thickened epoxy, after coating the balsa with unthickened epoxy. You can tell that water was getting under the flange of the thru hull in the photos. 5200 or any sealant will not be adequate. As the thru hull is tightened, it can, and will compress the core.

The balsa is end grain, and although balsa is "soft" it is a "hardwood" which has short cells, thus the water does not migrate Open cells will soak up the moisture. But unless there are channels it will not go far. You are correct that the kerfs and butt block areas where the squares meet, will allow water to flow. There is a hydraulic pressure as the boat flexes, and the water is pushed further along.

 

[clayhubler]

Okay, I got the moisture meter in and got some time to get to work. The meter pegs out at 35% for hardwoods, and you can see that most of the cabin floor is reading 35%. There were some dry areas up toward the front and outside of the hull. I wrote the value right on the floor so I could compare later to see if heating the core is working.

I started laying out a grid to drill quarter inch holes to let moisture escape once I put the heater in there. Then I started to drill. Lots of holes.

I found that I could kind of judge the condition of the balsa underneath based on the color of the shavings that came out of the hole. Lighter is good, darker is bad. This did reveal a few areas that I plan to cut out and inspect/ replace core. But on the whole the core appears to be in good condition, just wet. Wet is a relative term though, because most of what came out of the holes didn't really have enough moisture for me to detect it with my hands, even the areas that read the max moisture reading.

The worst area was right where those metal brackets for the cabinets were and especially where the foot pump was installed for the fresh water system.

 

[clayhubler]

Finished the holes and turned on the heat. The heater is a 4000 watt heater with a pretty good fan on it, really heats it up and moves some air, too.

Also, put this little dehumidifier in there to dry it out in case it gets steamy.

 

[smckean (Tosca)]

IMHO, dehumidifiers are very healthy for a boat. I have a commercial grade 180 CFM unit that can store 2 gallon of condensate without emptying. I run a heater and the dehumidifier for 2 or 3 days about once every 6 weeks in the winter (PNW climate). I typically get 5 to 7 gallons of water out of the boat each time (my boat is outside in a roofed and walled, but unheated boat house constructed from a "carport" type kit). After one of these treatments I can "feel" the dry air in there. All surfaces feel dry in the typical 45-50° temps with very high relative humidity we have here in the winter. Once "dried out" the dehumidifier dramatically slows down its water collection output.

clayhubler, you are going to be very happy you are not using the heater alone!

 

[Brewkid]

Holy Holes Batman!! Hope your cutout sections show only good things!

What diameter holes did you drill? Are they large enough to probe and check for dry rot? Only the area around my water tank where the screw holes were showed any real sign of moisture. The rest was just dry brittle fibers.

Look's like you're on your way to boating in no time!

R/
John
Scallywag.

 

[clayhubler]

The holes are mostly 1/4 inch. Most of the wood seems solid still, if damp. My boat doesn't seem to have the delamination issues you are fighting with. No soft spots, just wet and damp. There was definitely some rot in the cockpit, but that is getting replaced.

Sandy, yes, I think the dehumidifier is going to be a permanent addition to the boat when not in use. Right now I'm very happy I took the time to put decent electrical service to my carport.

 

[thataway]

Is your dehumidifier a compressor refrigerant/heater dehumidifier? I recommend this type, which I believe smckean (Tosca) has. The ones I have drain into the sink and then directly overboard.

You must have some major power source to run a 4,000 watt heater. 36 + amps! Not as much in vogue but we used to use infra red lamps directly on an area. --monitoring the temp is far easier now with IR thermometers.

Both "wall" and "Masonry" read to 100% scale,. You might just try that to see how it compares. It would also be interesting if you had access to an ultrasound meter, to see if the "wetness" measures the depth to the air on the outside, or if it just stops with the core...Normal core only reads the thickness of the inner glass. But if core is saturated, it will conduct the Ultrasound, thru to the air space outside of the hull.

 

[clayhubler]

I don't think it is a high end unit, but it is collecting water in the tank.

I did experiment with the settings on the meter and I felt that I might get a better reading with the other settings since it is all relative anyway, but I just stuck with the hardwood setting.

Looking forward to seeing how much water has collected in the tank in the morning, and also seeing if I have any reduced moisture readings. I think it may take a while, but the IR gun does show the floor getting up to about 135. I actually turned the heater down a little, because it initially got up to about 160.

Is there any danger of overheating the glass/ core? Can it warp or crack? The area reaching peak temperature is about 2 foot by 2 foot.

 

[clayhubler]

Just cut into the v-berth. Going to make extra storage space. Also want to be able to get any wet foam out and have access to that area to inspect for water. Originally I was going to buy the watertight hatches, but I have since decided that I want even bigger openings, and also my wife was concerned we would feel them under the mattress. I was a little concerned about that, too. This method is a little more work, but it fits my needs better, and is cheaper, too.
I do realize I no longer have a watertight compartment in the bow for flotation.

Unfortunately the bow was pretty much full of foam, and it is well adhered to the sides of the hull...

Luckily digging foam out looked like fun for my son... I suspect it wont be fun long enough to finish and I'll have to get in there tomorrow.

 

[thataway]

There are few if any "watertight" hatches which work on top of the V Bunk platform. I would not worry about loss of the floatation. If the boat gets to the point you depend on bow floatation, you have far bigger problems...

Looking good. I don't see any problem with temperatures in the mid `100's Fiberglass gets pretty hot as the resin "kicks off". It will burn, so keeping in the mid 100's is going to work as well as anything. What matters is what the temperature of the core is--and balsa is a fairly good insulator....

 

[clayhubler]

Alright, I've had the heater going for a day an a half out there, moving it around, and so far it looks really promising. Lots of areas that gave a max reading are now reading very dry. I realize that the meter is only supposed to read 3/4" deep, so I'm wondering if the readings will creep back up if I were to remove the heat and allow the moisture to equalize? The heater heats the area below it enough that the outside hull is getting warm. I plan to run the heater as long as it takes.

Also, was able to get the rest of the foam out from under the v-berth. I still need to get in under the porta-potti area and the small step in front of that. I think I may cut a small round inspection hole and get one of those hatches that screw in to put in the step area. The porta-potti area I don't know yet. Thinking of cutting a hole to remove the foam and dry the core, and then glassing it back in once the foam is gone. I don't see why I would need into that area again, with an inspection port just behind that, and I don't want to put a hatch there, because I want it flat for the porta-potti.

The foam was mostly dry. There was a few isolated pockets of water, but wet areas were mostly confined to under the step and porta-potti. I think most of the water that was in there probably got in from the black plastic plugs that they put in place after dumping the foam in. That is a low spot, below the porta-potti, and if water got in there it would have nowhere to go but seep down into the bilge.

Lots of space in there. I'm really glad I had such large openings to wrestle that foam, it was not easy and did not come out in large chunks. Rather, I had to chip at like an ice climber.

Got the helm off, too. When this goes back in it will be attached to a baystar unit.

 

[thataway]

Great job. I would only put the inspection plate on the first part of the area under the bunk--aft part. Any water will gravitate there. You may be able to pull the other material out, either from the forward, side or aft edges.

 

[clayhubler]

That sounds like a good idea. I think I'll do that, and then I'll just dry and seal the core in the forward part and put the plug back in. After epoxy sealing the edges of the hole.

 

[C-Wolfe]

clayhubler, I also had to deal with wet foam under the v-berth (it also smell like kerosene), I did very similar cutout as you did. I have a few pictures of that project in my photo album, Let me know if you need pictures of different angle, I have good access to the boat and can add to the album, but it look like you got it figures out.

 

[clayhubler]

Thanks C-Wolfe. Have you used the boat much since you did this modification? What are your experiences? I am worried about condensation on the inner hull surfaces that will contact the water. I'm considering putting dri-decking in there to keep stuff off the sides of the hull. I want to use the two side compartments for clothing, ect... and the front one for extra anchor, ropes... I am considering trying to get my daughter to make a sort of canvas liner that hangs from the hatch openings to keep stuff clean and dry for the sides. The front I will leave open, with the dri-decking.

 

[thataway]

Our 25 has never had any water in the forward compartments--my LiFePO4 batteries are on one side, the 2000 watt inverter on the other side--but both are kept off the sides of the hull by both plywood and foam "suspension". If I put clothing in theses compartments I would put them in a dry bag, or at least a water resistant duffle.

 

[C-Wolfe]

Thanks C-Wolfe. Have you used the boat much since you did this modification? What are your experiences? I am worried about condensation on the inner hull surfaces that will contact the water. I'm considering putting dri-decking in there to keep stuff off the sides of the hull. I want to use the two side compartments for clothing, ect... and the front one for extra anchor, ropes... I am considering trying to get my daughter to make a sort of canvas liner that hangs from the hatch openings to keep stuff clean and dry for the sides. The front I will leave open, with the dri-decking.

I have not used it since I opened the v-berth, I just purchased the boat in mid October and only use for a couple trial trip until the weather turn to single digit temperature. I will be adding a layer of something to protect the hull and keep thing dry that will be store inside, I look at a couple different kind of rubber mat or dry deck. If you look at my pictures, you will see an opening under where the porta-potty should be, I expect any water to collect there and can be removed with a sponge. I don’t expect much water to get under v-berth expect condensation.
Hope this help.