Thursday, March 27, 2014

Access Port Covers Starboard Tank

Finished making the cover plates for the access ports in the side wall of the Starboard tank. There are 32 bolts holding each cover plate on. These access ports will enable us to be able to inspect and clean the insides of the fuel tank. I would not be building new tanks if the builder had put access ports in the steel tanks...


Here is the last one in place. It is a pretty slow and tedious procedure to get to this point. After marking and drilling all the pilot holes in the plate I cut and glued the Buna-N rubber gasket material on the plate at the edges. The end of each piece was super glued to the side of the piece it met at the corner. Now line the plate up over the hole in the tank side and drill 2 holes though the side, one at each of opposite corners of the plate. These will be used to hold the plate in place while I drill all the other holes. Next the 2 holes at the corners are threaded and the bolts screwed in with lock-tite. After re-boring the 2 holes in the tank side with a clearance size drill I install the plate and hold it in place with nuts and washers. Now drill all the rest of the holes around the edges of the plate. After removing the plate all the remaining holes are threaded and the rest of the bolts installed. Next I re-bore the remaining holes in the side of the tank with the clearance size bit. The last step is to install the plate again with nuts and washers on each bolt and then cut the bolts off so that only about 1/4" of bolt is exposed from the nut. I like to do this then put acorn nuts on the exposed threads so they can not get all gummed up or mashed in the years before I need to remove the access cover.

Here are the other 3 plates for the starboard side tank.
The only thing left to do is figure out some kind of handle to put on the plates so you can hold them while putting them in place. They are put on from the inside with the nuts on the outside of the tank.










This is one of the four aluminum bars which will become the fuel manifolds for controlling the flow of fuel from the tanks to the engine, generator and fuel polishing system. It is amazing how fast it get complicated. I have designed most of the system...another post for that.

Sunday, March 9, 2014

Starboard Tank Progress





Made good progress on the starboard fuel tank Friday.

 Started out by cutting the lower laminate and plywood core out where the tank fittings will go.

This is a pic of the plywood side of the laminate that I removed for one of the spots. The first "ply" of the plywood was bonded to the glass work better than to the inner ply, meaning that I achieved a very good bond between the plywood and the glass skin. That is what you want.






Here is one of the completed spots. You can see the multiple layers of the plywood through the 3 layers of biax tape and mat I added the seal the core. This achieves two things(1) makes the wall thickness less so the bulkhead fittings will fit and (2) seals the core so even if the fitting leaks at the mounting hole the diesel can not get into the core.





That done is it was time to put the top back in place on top of the end walls of the tank down in the engine room. Not so easy by yourself, I had Chad and his friend help me take it out. But he was not home and I did not want to wait all day...so I muscled it in by my self...back is still not the same.


But here it is along with the center dividing wall
all glassed in. Next I will have to glass the top on where it meets the hull, dividing wall and both ends. This will have to be done both inside and outside the tank . Then I need to glass in the baffle in each compartment and lastly glass the side on. Next will come 2 coats of Vinyl-ester resin to coat all the polyester resin work. The vinyl-ester resin is impervious to more chemicals than the poly is. My main concern is when we start using biodiesel.
I have pictures of each of the joints and the taping for future reference. 

Tuesday, March 4, 2014

Laying up Fuel Tank Side

Making good progress on the tank side. I was able to complete the mold set-up and cut all the material yesterday and then lay it up this afternoon. Lost this morning at the doc's.




It turns out that the best way to cover the mold with wax paper is to dismantle it and wrap each part individually and then cover the plywood with wax paper and screw the pieces back down. That way you can get nice tight corners. I tried the other way of just covering each channel but the the inside corners are very hard and the wax paper is not very sturdy....















That way you can get nice tight corners. I tried the other way of just covering each channel but the the inside corners are very hard and the wax paper is not very sturdy....








I laid the part up this afternoon and the wax paper worked out very well.
The only problems were do to the cutting of the material and the hardener content in the resin.
In my effort to get good glass coverage I cut the pieces just a little too big so there was "rollup" at the sides and some buildup at the joints. Nothing that can't be corrected with a grinder.





Most of the layups I do are only 2 or 3 layers of combomat or biax tape. So it goes pretty quickly and there is just a little heat buildup. But this was much thicker part with 4 layers of 24 oz Combomat and 1 layer of 4 mm core mat using about 3 gallons of resin and it generated a fair amount of heat which caused the last layer to set too fast and melted the bottom layer of wax paper onto the glass. But over all I am pleased






The inside came out very flat with just a few wrinkles to fill. I can fill and grind the outside to smooth it out. The thickness came out fine at about 7/16". Sure saved a lot of money in resin and cloth doing it this way. The numbers you see were marked on the pieces to keep track of where they went. There were 57 pieces total in the 5 layers.  Onward!!!!