Yup, I am thinking that I will replace the forward bulkhead of the fuel bay just to see if there is moisture under the mid-cabin floor. There is a storage area just forward of the fuel tank bay and it has a couple of plywood ribs and foam below it.

Someone on iBoats suggested using hydrogen peroxide on the darkened area of the main stringers to kill the rot. I had not considered HP previously . . . thoughts on that versus Ethylene Glycol?

IMO the only way to do it and feel good about doing it is to cut it out. You could set a router up and take out the rotten wood and put a new piece in there. The reason that it does not stay in one place is that Formula (and most builders) lay the stringers in there and then glass them in. So if water gets in one area it can travel all over under the glass. If they put them in one piece at a time then glassed them in and then put in the next piece it would have stopped the migration of water. Of course then the boat would have cost a lot more….

Yes, I think that I will cut out the forward bulkhead and cut out the stringer-to-bulkhead tabbing to expose the darkened areas of the main stringers for a closer look. When I replace both bulkheads, I am going to encapsulate them in fiberglass first, so that they cannot readily absorb moisture, nor spread it to any of the adjoining structure.

Also did some research on hydrogen peroxide, it seems that HP is an active ingredient in the "brown rot" process of wood (dry rot). So, I think that any treatment of the wood to fend off rot will be ethylene glycol.

A quick update -

I happened to go to the New England Boat show last Saturday. . . took a look at the Formula 310 and 350 series that they had on display. As I was looking through the product literature, I noticed that Formula is using now "Perma Panel" wood in their hull matrix, instead of regular exterior grade plywood. I'm not sure when they made the switch . . probably a while ago. I believe that the Perma Panel product is from Inland Plywood Company. Chaparral boats use a similar product called Greenwood XL.

These products are pressure treated for rot, then Kiln-Dried After Treatment (KDAT), which makes them suitable for bonding with fiberglass.

Anyway, it does not look like I can get any Perma Panel at a retail level, but I may try to see if I can get something along those lines. Regular PT plywood would be too 'wet' and probably take months in the sun to 'dry out' to the point where it could be used in the boat's structure for repairs.

While I was at the Boat Show, I noticed Scott Porter (Formula Boat's President) was there . . . I chatted with him for a while about the product lines, noting that there was currently a fairly big 'gap' between the 310 and the 350 lines. If I were to go new at some point it would be nice to stay in the 33' range. The 310 seemed tight vs my 330 and the 350 is just too big for my mooring space. Maybe they will have something new in the future to fill that 'gap'.

Progress report:

My progress report is that I have no progress to report, sorry to say. Been busy with work and life's happenings. I hope to get some time to work on the boat this coming weekend. Next steps are to:

1) Prep the fuel tank down to bare metal. I should probably take a look inside it via the sender hole and flush it out.

2) Remove the foam from the fuel tank bay.

3) Then, it will be a matter of trimming the bulkhead edges from the cutting that I did at the outset of this project. I also hope to get a look at the center engine mount stringer, once I cut the remnants of the bulkhead away from it.

4) I think that I will replace the rear bulkhead first, then decide what to do about the moisture I found in the forward bulkhead.

I'll definitely need some warmer days to make good progress, and probably will have to come up with a way of heating the boat's internal areas in order to do the fiberglass work. . . . Maybe a portable heater ???? Not sure it would be enough.

Here is an update on the foam removal and finish cutting of the bulkhead . . .

The weather was fairly warm yesterday and the predicted rain held off, so I was able to be quite a bit done.

Here is the fuel bay cleaned out of all the foam. It was fairly wet in many areas, so I am glad to be doing this work now, rather than a few years from now.



I took some moisture readings in the forward bulkhead, which has become an additional concern once I exposed the inside face of it.

Fairly high in the lower section within the moisture pattern.



But better higher up . . .



I also checked various areas of the main stringers and those too showed 12-15% moisture, which is what I've found to be typical of encapsulated wood.

I did some finish cutting of the rear bulkhead. Here is the cut-out area and the intersecting surface of the center engine stringer.



The outer plywood of the center stringer looked a bit dark, so I may do some 'chemotherapy' treatment of the wood to prevent deterioration.

I also cut away the shower bilge mounting plate, as I will need that area to tab in the new bulkhead. Notice the crack that I found in the lower face of the stringer, indicating the moisture absorption. I may cut the fiberglass skin off in order to get a better look at the wood inside.



Last year, I exposed the side of this stringer to get a look at the wood, and it was fairly dark to about 6" up. So, early signs of progression there.



After a few months of exposure last year, the wood had showed some improvement . . .



So, I will have to see what the forward face of it looks like.

I started the paint striping of the fuel tank yesterday, and will probably finish that today.

I also took some time to do some measurement of the foam chambers throughout the hull, since everything is pretty well exposed. I calculated the volume of flotation to be about 67 cubic feet, including the fuel tank volume. (so, I'll add the weight of the fuel in my further calculations)

I am considering adding some flotation to the structure before I button things up. So, knowing how much is there to begin with is a factor and consideration as to how much I should try to add.

Here is my flotation calculations from my F-330 web site (for those interested):
http://home.comcast.net/~tpenfield/F...Flotation.html

I had figured that the materials in the boat would displace about 79 cubic feet, based on their density, and the 67 cubic feet of 'flotation' would bring the total displacement up to 146 cubic feet, which is about 9,100 lbs of water. So, the boat is close to being able to float. The bare boat, without fuel in it would probably float, but with the fuel in would probably not.

Anyway, a bit of an aside from my bulkhead work, but since the boat is all opened up, it is a good opportunity to do a bunch of things on my 'list' of improvements.

Morning tpenfield, there is a lot going on with your project. Won't be long before it's boat-n-water time. Doing a great job and thanks for the Pics on all the sites.

I briefly looked at your floatation calculations and noticed you used the dry weight at 8900, the new 310 is 9700. Is your 330 that much lighter?

Yes, the first few years of the 330 were spec'd at 8900 lbs. then the weight was increased to 9700 lbs, probably due to the radar arch and some other goodies being added along the way.

I might be in a pinch to get all the work done before my normal launching time. We will see how it goes. I also have some outdrive maintenance ahead of me.

Fuel Tank Paint Preparation Update:

I did some work on the fuel tank this weekend. Previously, I had applied paint remover to the tank and it did a pretty good job of loosening the paint. Then, I did some wet sanding to take off some of the more stubborn areas.

Here are a few pictures of the tank.

Top surface and the fittings . . .


Forward End of the tank . . .


Bottom side of the tank . . .


Here is a video of the day . . . checking out the inside of the tank.

http://www.youtube.com/watch?v=WiTk2coBTOg The inside surfaces of the tank, to the extent that I could see, looked very good . . . basically like new. I just need some warmer weather so that I can paint the tank. It might have to wait a month or so.