Epoxying fuel tanks on Black Star

May 21, 2008
30
Alden Challenger Portland
After a lot of work getting the 200 odd nuts off by unscrewing them or splitting them with a nut splitter or as in the case of 7 of them shearing them,I finally got the plates off the top of the fuel tanks.They were clean on the topside but rusty on the underside from condensation which I planned to grind off and when we have a nice warm day I shall apply 2 coats of epoxy.The keel bolts are covered by thin glass cloth which I think has been covered with a resin of some sort,I feel I should remove at least one keel bolt as after 50 years they could have suffered dezincification and be in danger of snapping,has anybody done this and how difficult was it?I should hate to drop that great lump of lead somewhere and try to sail home.
I am reasonably happy that the epoxy resin will adhere to the tank insides as it must be a least 10 years since Blackstar has had fuel in them and they are quite clean and odour free under the debris from the tank tops and I feel the epoxy will make them more impermeable to both fuel and water leaks.
Then hopefully I shall manage to get beyond the mouth of the Connecticut river this summer as I lay on a buoy last summer and only motored into a dock to take on water and charge batteries,but I was onboard during Irenes passing.

Philip Dann
 
Jun 28, 2004
50
Phillip,

Lots of nuts to remove! When I replaced the tank covers on Whisper I also replaced all the bolts, and found that the most forward (and most aft) outboard bolts didn't have enough room to be removed - the angle of the hull was too tight. (Apparently the floor was glassed to the hull after the bolts had been put in the holes). I had to saw off the heads underneath and take them out from the top. (Milwaukee makes a Sawzall with a folding handle that can fit in tight spaces) To replace these, I put the new bolts in from the top, and put a nut on the bottom (with thread lock), and then sawed off the head on top. So far, everything is tight. You can check out pictures of my job which are in some of my posts.

The keel bolts were not covered. One nut had split and was off. It had dissolved somewhat over the years and was a bit thin, as were all the other nuts. I replaced the missing nut, and backed up all the other nuts with new ones (Si bronze from Jamestown Distr.) just to be safe. The nuts that were still on the keel bolts were too tight to remove, and I didn't see the benefit of taking them off, especially when weighed against the chance of messing up one of the bolts.

I didn't epoxy the tank interior. It was discolored and there seemed to be some penetration of diesel into the hull. I didn't want to grind down the inside of the tank, which would be very hard to do, what with the ribs and baffles. It wasn't clear to me how well epoxy would adhere to the surface, and I didn't want it to later flake off and gum up the fuel system.

Good luck, and we look forward to seeing you when you are afloat!

Rick
 
Jan 27, 2012
12
Good Morning Philip:

Check with some one about using epoxy over the current glass (polyester?). We had issues with the top of our centerboard trunk which had been patched over the years with every thing from bondo to 5200 to liquid nails to epoxy as well as paper towels for filler. The glass man at Boothbay Region Boatyard said alot of the problem was epoxy doesn't like to bond well to the poly esters. Of course our trunk started leaking after we massaged a ledge!

Jon
 
May 21, 2008
30
Alden Challenger Portland
Thank you both for the advice,I had read Ricks previous on his tank cleanup and with Jons advice I may just clean the tanks and leave the epoxy but I am not sure what resin was used to make the glass cloth adhere to the keel bolts and the current resin.I feel that I should expose at least one of the nuts and check it for corrosion but I am still a little worried about the bolts where they enter the lead and may have been exposed to salt water at the keel to hull joint.I have run a die nut down all the old tank bolts and will fit either new bolts or studs where the underneath is not accessable and then make up some new gaskets and refit the lids.
I am a little puzzled as to where the diesel return line fed into the tanks,when I bought the boat it was fitted with an Atomic 4 and a small local tank,I assume a tee-ed in connector to the large vent pipe would possibly have been used,I might use that anyway.I may also fit a small ready use day tank also in case of fuel pump failure and or dirt appearing in the main tank again,this shows that I spent 15 years as a British navy reserve engineer where this is standard practice.

Phil Dann