Inspecting and Cleaning Original Fuel Tanks in 2002 Grady 330

[usmm1234]

I was a little concerned with the possibility of corrosion effecting my fuel tanks. The boat is 17 years old, and I know Florida Marine Tanks only used Automotive Primer on the tanks back then. They have since upgraded a couple times in how they protect the tanks. If you look at your GW manual. They actually suggest you rinse the tank periodically. Very few ever do.
I could see some white oxidation around the fills, vents and pickups under the deck plates. I needed to redo the caulking anyway because someone had totally botched the job before I owned the boat.
I went ahead and backed out the screws and cut out the caulking and pulled up the deck. Actually very easy. There were white oxidation marks around the top of the tanks. Not too bad. I sprayed them with PB Blaster Penetrating spray and let it soak. They all dissolved. Then I mixed a bucket of water and Salt Away and drubbed the tanks with a 3M pad and the Salt Away. I poured the left over down the sides of the tanks. Then I left the boat in the sun for a few hours to dry out. Then I sprayed liberally with BoeShield before closing it back up. Hopefully I’ve extend my tank life a little?

 

[seasick]

What you did won't harm the tank and will help reduce corrosion around the sender flange but the reality is that in most cases, the corrosion occurs on the bottom of the tank where it rests on the supports.

 

[usmm1234]

What you did won't harm the tank and will help reduce corrosion around the sender flange but the reality is that in most cases, the corrosion occurs on the bottom of the tank where it rests on the supports.

Affirmative on that. As I mentioned. I needed to dig out the crappy caulking job the previous owner’s captain did on the deck panel. He pulled the deck section and took it to a fiberglass shop to have it reinforced, which is great. But when he put it back in. He used silicone Right over all the old Boat Life. It was the worst caulking job I’ve seen in 42 years in the boat business. I have replaced numerous tanks in older boats that were foamed in. Thank God Grady didn’t do that anymore. I dumped gallons of the Salt Away solution down the front back and sides of both tanks. Who knows? It only took an extra hour.
The nice thing is that they are easy to get out if you need new ones.

 

[TheBlackPig]

Here's what my my easter 2021 hols went on + the weekend after + a few hours after work too


Opened up the tank hatch for the first time since I bought this Sailfish 272 1997 four years ago. I'd detected some fuel smells when I opened up the inspection hatches. Both fuel senders were totally shot and way overdue for replacement.


Previous owner had tried a temp fix with some non fuel proof sealant.


Cleaned off the tanks with marine spray cleaner and a green sponge.


Removed old sending units and cleaned everything up with carb cleaner and pointy plastic picks and some microfiber rags.


Then I mixed up some JB Kwik Weld and leveled out all the pitted area around the holes and other areas around the tanks . Let it set for about half an hour (sets in 6 mins). Then installed the new proper Wema sending units using a thin coat of Blue Hylomar on all surfaces before tightening down.


A final cleanup before coating with International Interprotect, a two component epoxy barrier coat.


1st coat


2nd coat

Hopefully she's good to go for another X years...

Worst thing about this project was cleaning up the silicone from hatch and floor edges. It has to be squeaky clean or the new sealant will simply not adhere properly and fail down the road. Spent 10 hours or more on that alone. Now a bit in doubt what to use as the new sealant. Bought a tube of Sikaflex 291i, but having second thoughts as its an adhesive/sealant. I'd like to think there is a better alternative out there so the cleanup isn't as brutal next time. Anyone?

 

[Hookup1]

I'm using 3M 4000. UV stable, mildew resistant. I went thru this whole discussion of cleaning tanks and how to test them on an earlier thread. Long but worth reading.

Removing aux tank on 1999 268 islander

It wouldn't be the 1st Grady that I've heard of with a drain tube that was glassed over. I'm likely stating the obvious, but my forward compartments won't drain to the back unless the boat is on a significant incline. Are you sure you have enough slope to get the compartment to drain back to the...

www.greatgrady.com

 

[Fishtales]

Nice job but likely will not do that much to extend the life. 20 years is my estimate on the stock tanks. They are making large capacity poly tanks now. May be an option for us in the future.

 

[Hookup1]

Nice job but likely will not do that much to extend the life. 20 years is my estimate on the stock tanks. They are making large capacity poly tanks now. May be an option for us in the future.

Nice job usmm1234!

I went in with the expectation that the 23 yo tanks should be leaking by now and would replace them. But they checked out ok. I included my testing procedure and tools to help other GW owners out when the time comes. So I kicked the can down the road a little! In the process of investigating the fuel compartment and bilge it was amazing how much misinformation was out there. Including the cleaning procedure and how the fuel compartment drain. FYI fuel compartment should be isolated from the bilge. There is a way to drain it - pull a plug but replace it! It keeps you from blowing the boat up!

I like the idea of poly tanks but it doesn't seem that popular. We'll see. I saw a at the top of this post where someone did an amazing job cleaning the tanks up and installing a new sending unit. They did it all correctly. I would have smoke tested/pressure tested the tank too to be sure. Unfortunately tanks are like boats - they don't leak from the top - it happens on the bottom. I suppose if the aluminum tanks are epoxy coated and properly installed they could last indefinitely. But even clean water against the bedding material leads me to believe it will eventually be a problem. The only way to really "know" what is going on is to pull the tank and if you are going that far you might as well replace it.

 

[fsc60]

My 330 is an 01, My deck was soft, caulk was terrible so I removed it to recore the deck panel. After opening up I was shocked at all the dirt and mildew plus some corrosion. Pumped the tank dry and removed it. It really wasn't that bad. I took it to my shop and pressured washed it with hot water and some bleach. After it was good and dry I gave it 2 coats with barrier coat epoxy. I also pressure washed the cavity for the tank and cleaned the second tank, it was not bad at all. I Bilge painted everything I could and barrier coated the other tank. All new hoses and clamps. Recaulked the deck with the Grady almond caulk. I agree worst part is cleaning the old caulk. Looks great and hope to extend the life of the tanks.

 

[fsc60]

Here's some pics

 

[Hookup1]

When the deck coring fails it leaks plywood glue all over the place. It makes the tanks look worse than they are. The most likely place for the deck hatch to fail is the screws. Try as you might to create the sealed screw holes. I used Coosa Board composit for coring.

 

[fsc60]

I agree, we used Coosa also, just did the hatch to the bilge, wood was wet, now all composite

 

[HMBJack]

Great job USMM. What you, Black Pig and FSC did is what we all should do once every 10 (?) years.

I FW rinse my tanks annually and have changed out those leaky push in inspection caps with Beckson screw in types.
This helps keep my tanks dry but it's what we don't see that matters most. Only way to really know how your tanks are doing is to remove the deck panel as you (Black Pig and FSC) did. Well done and thanks for the post and photos.

 

[Palmolotte]

Here's what my my easter 2021 hols went on + the weekend after + a few hours after work too

View attachment 20041
Opened up the tank hatch for the first time since I bought this Sailfish 272 1997 four years ago. I'd detected some fuel smells when I opened up the inspection hatches. Both fuel senders were totally shot and way overdue for replacement.

View attachment 20045
Previous owner had tried a temp fix with some non fuel proof sealant.

View attachment 20042
Cleaned off the tanks with marine spray cleaner and a green sponge.

View attachment 20043 View attachment 20044
Removed old sending units and cleaned everything up with carb cleaner and pointy plastic picks and some microfiber rags.

View attachment 20048 View attachment 20050
Then I mixed up some JB Kwik Weld and leveled out all the pitted area around the holes and other areas around the tanks . Let it set for about half an hour (sets in 6 mins). Then installed the new proper Wema sending units using a thin coat of Blue Hylomar on all surfaces before tightening down.

View attachment 20051
A final cleanup before coating with International Interprotect, a two component epoxy barrier coat.

View attachment 20052
1st coat

View attachment 20053
2nd coat

Hopefully she's good to go for another X years...

Worst thing about this project was cleaning up the silicone from hatch and floor edges. It has to be squeaky clean or the new sealant will simply not adhere properly and fail down the road. Spent 10 hours or more on that alone. Now a bit in doubt what to use as the new sealant. Bought a tube of Sikaflex 291i, but having second thoughts as its an adhesive/sealant. I'd like to think there is a better alternative out there so the cleanup isn't as brutal next time. Anyone?

Great job! Appreciate the info and pics. I have a ‘96 272, that I purchased last year, and am having some fuel issues. I want to put new fuel lines from the tanks to the filters but my boat is 4 hrs away and wanted to order some fuel line before I head down. Any chance you know the size and approximate length of the lines from both tanks to the filters or selector valves?

 

[fsc60]

I can look at mine tomorrow and get the size, I don't remember the size off hand. West marine sells it by the foot, I probably went thru 50 feet easy doing 2 tanks and 2 engines.

 

[Time Bandit]

Here's some picsView attachment 20054View attachment 20055View attachment 20056View attachment 20057

Nice job. We’ll done.