Advice on fuel tank covers please

[Bumpye]

Looking for advice on removing the covers on the deck that cover the fuel tanks on my Gulfstream. I seem to remember reading here that Grady recommends doing it every 5-6 years and replacing the seals. I searched but was unable to find any info. Has anyone done it, are the seals still available (2003 boat)? Thanks for any input.

 

[DennisG01]

There are definitely many threads about removing fuel tank hatches (and probably literally hundreds in Google land). And it's been pretty much the same from one to boat another. There's really nothing to it - it's as straight forward as straight forward gets... remove screws, slice the sealant, remove the hatch. However, if your main purpose is to "reseal", 5-6 years is probably overkill if good sealant has been used. How do you know if it's time? Look at the condition of the sealant that is in the gap. That IS the "seal". Meaning, I think you're getting confused about what "seals" the hatch.

 

[Bumpye]

Thanks for the advice Dennis. You're right, I was assuming the gasket/ "o ring" seal (if there are any) around the hatch was the seal. I didn't think there would be a silicon sealant around the hatch as well (had these thoughts while anticipating removing the shrink wrap without actually seeing the hatches). My thought was to also check the tanks, hoses, and clamps.

 

[glacierbaze]

Are you referring to the large rectangular pieces down the center of your deck, or the round pie hole inspection ports, and their frames?

 

[DennisG01]

Glacier... good question. Bump... clarification?

 

[Bumpye]

I was referring to the large rectangular covers. After reading Dennis's post I will leave the rectangular covers in place providing the sealant looks good. I plan on removing the round inspection covers, which I have done before to wash down the tanks, and inspect what I can see. May use an inspection camera.

 

[journeyman]

I plan on removing the round inspection covers, which I have done before to wash down the tanks, and inspect what I can see. May use an inspection camera.

If you're not already planning to, I would take the extra step and unscrew and remove the the whole thing. Quick and easy. It will give an extra inch or 2 to have a look around and you can re-bed it with silicone once done. I found the 3 plates in my Euro transom had very little (if any) sealant after a day of drift fishing, taking a few waves into it and having my bilge pump come on. Thought it was just the O-ring but it wasn't.

 

[Ky Grady]

I would have to second what journeyman said and go on and pull the panels. That way you can have a look see of the tank better than a couple of six inch holes. Give as much of the tank a wash/rinse that you can and if saltwater boat, spray as much fresh water that you can to rinse away as much salt that you can. I went crazy with the water spraying in every nook and cranny that I could hit with the panels removed on my 228. At least I feel I've done as much as I can do short of pulling the tanks. Reseal under the rings and the panel with GE Silicone II in Almond and go fish.

 

[DennisG01]

Thanks for the advice Dennis. You're right, I was assuming the gasket/ "o ring" seal (if there are any) around the hatch was the seal. I didn't think there would be a silicon sealant around the hatch as well (had these thoughts while anticipating removing the shrink wrap without actually seeing the hatches). My thought was to also check the tanks, hoses, and clamps.

Just to be clear, there is no "as well". Meaning, the ONLY seal is the caulk/sealant (whether silicone or other formulation). There is no gasket/o-ring around or under the large, rectangular, fiberglass floor hatch.

 

[Denko]

There is no gasket/o-ring around or under the large, rectangular, fiberglass floor hatch.

OK now I have to ask. When I pulled my 3 floor hatches I found strips of rubber in the corners and along the edges where the screws went through, and the bare areas between them had 'shadows' that looked like the strips were there and now gone. They were the same material that was used between the fuel tanks and the wooden wedges that secure them. I got a roll of rubber from Amazon and cut to size and replaced it all. Was this stuff not factory installed? I also pulled the inspection plate frames as a few of the mounting screws were stripped. I thought I did a good job of drilling them out and filling with epoxy, but I guess epoxy alone wasn't enough to hold the threads. This year I'm going to pull the frames again, re-caulk and replace the screws with a nut and bolt. Cleaning the fuel tanks and lines and general bilge area was a pain but it looks waaaay better now! 8) 8) 8)

 

[DennisG01]

Dennis,

I'm not professing to be an expert on this subject, just that in my years I have never seen hatches sealed with anything other than caulk/sealant in the perimeter gap. Could the rubber pieces you saw have been put there to sort of "shim" the hatch? Or maybe it was there as an attempt to keep the hatch from squeaking when being walked on. I don't know, though - maybe it was an attempt to seal the hatch that was a short-lived option? Meaning, it was an idea that they tried out to see if it would work or not? Again, not sure - just thinking outloud there. But, personally, I don't any reason to start messing with other ideas when the perimeter caulking works so well. I certainly don't see a piece of rubber being a good, long-term seal in this application - water would still find it's way past the rubber. Foam rubber would work better (as a seal) as it's compressible and would take up the irregularites between the floor and the hatch edge.. but it would lose it's compressibility and flatten out over time.

Inspection plates... filling the holes with epoxy (possibly thickened or some glass, depending on the damage) SHOULD work. But certainly using thru-bolts and nylocs will solve the issue. If you don't need to pull the big hatches, I would think you can install the bolts/nuts through the inspection hole? Another thought... rotate the plate and redrill for new screws. Still another thought... a good adhesive sealant (NOT 5200... way too strong) will actually do most of the work. A little on the screw thread and under the screw head will keep the screw in place.

 

[journeyman]

When I pulled my 3 floor hatches I found strips of rubber in the corners and along the edges where the screws went through, and the bare areas between them had 'shadows' that looked like the strips were there and now gone. They were the same material that was used between the fuel tanks and the wooden wedges that secure them. I got a roll of rubber from Amazon and cut to size and replaced it all. Was this stuff not factory installed?

They were there on every floor panel I've ever pulled and yes, they were factory installed. First panel pulled was on my last boat that I bought new and there they were. The rubber has(had) adhesive on one side to keep it in place. The shadow area are from ones that have fallen off. They are still somewhere in your boat, hopefully not clogging anything up. I believe they are there for a couple of reasons. First to prevent glass on glass when panel is in place. Second maybe(theory) is to slightly raise the panel so water can run off and not pool.

 

[Denko]

I'm not really sure what the function of the rubber is, and it is in addition to the caulk in the gap. Maybe to help seal the screw hole, or keep the surfaces from rubbing? I hadn't considered rotating the plate itself and re-drilling. I don't think I'll have to pull the large panels to through bolt, but I will be buying extra nuts . For anyone wanting to replace the o-rings, I did find the best price at Walmart online and was able to pick them up at my local store.