Starboard fuel tank Progress

I have been pondering how to build the side of the fuel tanks with access ports so that the tanks can be cleaned and inspected....With there being 2 tanks,and each tank having 2 chambers(due to the baffle) that meant having 4 access covers. The access covers for the water tanks worked out all right, but were a lot of work. The problem is in attaching the studs to the fiberglass well enough that they do not come loose when you are taking the covers off. For the water tanks, I made aluminum bars that I threaded the studs into with locktite and then embedded the bars in the fiberglass. It turned out to be a very slow process. For the fuel tanks I decided the mount the studs in the covers and then have the covers bolt into the tank from the inside rather than the outside. Then the liquid pressure will be pushing the cover onto the tank wall rather than off.

 I also decided to make the the covers using 1/4" thick aluminum rather than fiberglass. That way I can just thread bolts into the aluminum with locktite and then seal the back of the cover with what ever I coat the inside of the tanks with...
I have not come to a decision on that yet.





After drawing the side out I realized that there was not much side left after you cut the access holes out. I usually make these parts using 1/2 Power ply as a core, but there would be so much waste it did not make sense. Then I realized that there really were not any large unsupported areas and a core was not necessary.

Rather than lay-up the whole side and then cut the access holes I made a simple mold for the side. I will line the mold with wax paper so the resin will not stick to it. I cut all the strips of 24oz  combo mat and 4 mm core mat to fit in the spaces that represent the wall. There will be 5 layers total, 2 layers of 24 oz. Combo mat followed by the core mat then 2 more layers of 24 oz. Combo mat. I lapped the joints in each consecutive layer. The total finish laminate should be 7/16" thick, more than enough. Between the center dividing wall and the two baffles the side will have plenty of support.







Tomorrow we are off to the Trawler Fest here in Palm Beach Gardens to see what inspiration we can find.

Starboard Fuel Tank top started

Finally back to work after a week off to move mom....
Today I started on the starboard fuel tank top. Yesterday I cut holes in the cabin sole of the main cabin.

The top of the fuel tank will be 12 inches below the Cabin Sole, lots of good storage space. Good place to stick a compressor/condenser unit for the Freezer or Main Cabin AC. I plan to make the inboard side wall of the tank come all the way up to the cabin sole. This will provide support for the cabin sole as well as divide to engine room from the storage space.

A view down through the aft access.
I have not finished the tank yet. You are looking at the floor and aft end of the tank.

Here is the top for the starboard tank with 2 layers of combo-mat on both sides. In this picture you can see the vacuum bagging film covering the glass work. I cover the glass work before it sets to keep the finished surface from contacting the air. The resin I am using does not have any wax in it, so the cured resin will still be tacking for days. If you excluded the air then it sets hard. You can buy resin with wax in it to accomplish this. The problem with the wax is that you have to grind it all off to get a good bond with any glass work you attach to it....So no wax, the vacuum bag sheet does the trick for most of it. The problem is in getting all the air bubbles out....

 Same top with the plastic removed, ready to trim the edges.












I am using 1/2" thick Power-ply as the "core" of the walls and top of the tanks. I have given the sheets in this picture one coat of resin in preparation for glassing. They are yet to be cut to size. I just coat them with any extra resign I have left over while glassing.

Progress on the Starboard Fuel tank walls

I decided to fill and sand the faces of the tank walls before I put them in the boat. Hoping to not have to spend so much time sanding before I coat the inside of the tanks.

So here is one of the walls after I have trimmed the excess glass off from around the edges and filled and sanded both surfaces.



 The forward wall all glassed into the hull and one coat of resin to seal everything up. The walls are tabbed in with 4 layers of 24 oz Biax tape. I cut the tape into a 4",6",8" and 10" width the glass them in starting with the 4 inch covered by the 6 then 8 and finally the 10" over all. That way the tabbing will be tapered with only one edge exposed.

Here is the aft wall which I was not able to finish taping in the aft side. Ran out of Biax tape. So I did the front side today. You can see the temporary brace I installed to hold the the wall in the correct position until the glass set.

Forward and Aft walls of Fuel Tank

Started putting the Starboard fuel tank together today. Made patterns for the forward and aft end walls using 1/8 Masonite.

Here is the pattern for the aft end. I cut strips of Masonite then shaped the edge of the two that have to conform to the shape of the hull. Then I glued those two together in the right position to conform to the angle of the chine. Next pieces were added the represent the top and inboard side. The problem is in gluing them together with hot glue while making sure they were either level or plumb... that is when my two extra hands and arms would have come in handy. 

After checking to make sure they fit right, I traced their outline out on the 1/2" plywood. After cutting them out and checking the fit once again, I covered each side with 2 layers of 24oz Combo mat. After laying them up but before the resin set I covered them with Vacuum bag material and placed a flat smooth panel on top with weights. That will give me a good start on having a smooth flat surface when done.
Thinking of buying a vacuum, pump for this. Could be used for AC work too.

Here are two pics of the panels after the plastic has been removed. There are still some wrinkles in the finish, but far better than the finish if the roving had been left to cure without the plastic.



The plan is to glass these two pieces in place tomorrow then fit the dividing wall in the middle. I wanted to get the two end walls in place first. Then I can make sure the center wall is in line with the ends so the top and inboard walls will be straight.

Beginning of New Fiberglass Fuel tanks

Well after 2 days of removing problem thru-hulls that were either plastic or had bad rotten backing blocks and grinding all the junk glass work off ,I finally got started on the new fuel tanks. I also discovered that the generator exhaust, which is 2" diameter hose was hooked up to a 1-1/2" thru-Hull.
How much more could a 2" thru-hull have cost? I bought a new stainless steel one for $50.00 or so!!!

After cleaning all the dust out I laid out the lines for the sides of the new tanks. I then cut 1" thick Polyurethane sheet to get fillet strips  which accomplish two goals(1) they keep the wall of the tank from creating a hard spot in the hull and (2) they keep the fiberglass tabbing from having a sharp 90 degree  bend which is weaker.
I glued the strips for the 3 transverse walls of the tank in with hot glue. It only needs to hold the strip in long enough to shape the wall and glass it in. Then they are buried in glass and not going anywhere.

One more shot of the strips. Hopefully Thursday I will make the 3 walls and glass both sides in prep for installation. My plan is to build the ends and dividing wall first, then the top followed by the inside wall. I will have access ports in the inside wall. After glassing them all in I will build and glass in the baffles in each tank. The baffle does not have to seal against the hull as do the other walls and top.