Grand Banks Fuel Tank leaks

[RickBeach]

We have 42ft Grand Banks classic and the feul tank leaks. Looking for someone that has replaced the tanks for help and guidance.

 

[Cigatoo]

We have 42ft Grand Banks classic and the feul tank leaks. Looking for someone that has replaced the tanks for help and guidance.

If you go up to the search area and search under “fuel tank” you will find enough to keep you busy all week. Here is a recent thread. Not a GB but similar and a nicely detailed explanation.
https://www.trawlerforum.com/forums/s6/fuel-tank-replacement-job-39628.html

 

[fryedaze]

Rick, the link provided was my boats tank replacement. It gives you an idea of what's involved, but the tank replacements on GB 42s that I have seen are a little different. My replacement tanks are side by side. The GB 42s I have reviewed stacked three tanks on top of each other. There are probably plenty of 42 guys here that can help.
The GB owners forum may be a better source.

 

[Cigatoo]

Also the “Grand Banks Owners Group” on Facebook is helpful. Search on fuel tank.

Sadly the Grand Banks owners forum is no more. It had a wealth of knowledge available. It kept getting hacked and the administrators gave up. A real shame.

 

[SteveK]

youtube has videos of fuel tank replacements

 

[Old Sea Dog]

Fuel tanks in our '79 GB 36 were replaced with aluminum. While we have just over half the capacity, 210 gal vs 400 gal, there is the possibility of adding another tank stacked on top on each side.
Root cause of the problem most likely is water leaking around the deck fuel fill fittings.
Size of the tanks will be limited to the access you have; ie 2 larger vs 3 smaller tank stacks.
John Shannahan at Oxford Boat Yard is the GB guru.

 

[mvweebles]

I've read several stories about fuel tanks being replaced with much smaller sizes tanks. Does anyone have a sense whether a significant reduction in capacity affects resale price or interest?

I replaced my tanks and lost about 5% capacity, so not much. Was important to me to have at least 1500nm range (I now have close to 2000 nms). But wondering what the general consensus is.

Peter

 

[hmason]

Before you jump into replacing the tanks, see if a repair is possible.

 

[Comodave]

I've read several stories about fuel tanks being replaced with much smaller sizes tanks. Does anyone have a sense whether a significant reduction in capacity affects resale price or interest?

I replaced my tanks and lost about 5% capacity, so not much. Was important to me to have at least 1500nm range (I now have close to 2000 nms). But wondering what the general consensus is.

Peter

I can’t say for sure with previous sales, but if I were the buyer and the particular boat had significantly smaller tanks I would not buy it.

 

[Steve DAntonio]

I have supervised this task on a few occasions, replacing with multiple aluminum tanks for similar capacity. Not a small task, but doable and it has been done enough that there should be few surprises.

Do not let anyone cut the hull to remove and replace the tanks, doing so introduces a large secondary bond, which, among other issues, could void insurance coverage.

New tanks should be built by dedicated tank fabricators, not a general fabricator, and they should be ABYC compliant. If the tank builder doesn't know what that is, look for another.

More here...
https://stevedmarineconsulting.com/fuel-tank-installation/

https://stevedmarineconsulting.com/fiberglass-repair-and-secondary-repairs-steering-you-straight/

https://stevedmarineconsulting.com/wp-content/uploads/2014/03/FuelTankDesign.pdf

 

[Brooksie]

Before you jump into replacing the tanks, see if a repair is possible.

What he said.


I repaired my lobster boat tank 10-12 years ago using Por 15 & Por 15 paste from the outside. Leak was at a welded seam on bottom, builder had installed the tank on pieces of plywood which had held moisture against the steel. After repair I replaced all these with plastic log splitting wedges glassing around them (3 sides) so they couldn't move. Never another problem.

 

[Deckape]

Replaced my tanks on a Jefferson 45' aft cabin . Hard part was getting the new tanks in the boat . Had to reduce the dimensions by 2" so they would fit thru a window that was the same shape of tanks . Cut old tank up with a saws all and pasted the pieces thru the door . After reinforcing the floor from underneath in the engine room , I setup a A-frame in the saloon . Lifted engine up and over the other engine while getting tank in thru window . Set in place and moved engine back into bed . Hooked systems up and started on removing other engine and tank . Took two weekends with help from friends that I gave diesel to for labor ,and me working after work . Yard use forklift to get tank up to window and four of us to get tank set in place . Not heavy, just bulky and open engine access in saloon . Tanks about $ 4,000.00, labor free plus hog dogs and beer after setting of tanks . Had estimates of up to $30,000.00 to remove both engines out the door ,tanks and labor . Another wanted to access tanks thru hull , like a big 70' Hatteras and when asked , " How do you repair ribs and glass on outside of tanks once in boat ? " Deer in headlight look . Decided to do it my self and worked out fine . If a yard is going to do it , get with others that they have done . Coated tanks with cold tar and made several more weep holes and other repairs were water was getting to them . Good luck .