Slimy fuel tank grime & wet bulkhead???

[bjflink]

I just removed the two pie plates on my 2000 GW 306 between the helm bench seat and console footrest to inspect my forward fuel tank.

First thing I noticed was an incredible amount of wet sludge on the top of the tank around the sending unit and fuel pickups. I scratched at it with screwdriver and there is nice shiny aluminum under it all, so thankfully no corrosion. How would you recommend I clean it all up? Plastic bristle scrub brush and then rinse?? Any mild chemical cleaner? Any good/safe way to get it all dried back out?

Second thing I noticed was a vertical bulkhead just forward of the tank. I cant see it, but reaching my arm into the most forward of the two pie plates I can feel it. It has a light coating of slime and feels pretty damp. I also stabbed it a few times with a screwdriver and it feels like nice solid wood. Ideally, I'd to find the source of the wetness, and then dry out before there are any issues. I have no idea though how it could be getting wet. Both my forward and aft bilges always have a small amount of standing water in them...basically the residual that is left from my pumps not able to get the bilge 100% dry. The pumps never run though, so as far as I can tell I dont have any major water intrusion issues.

Thanks!

Thanks!!

 

[SmokyMtnGrady]

If your boat is on a trailer I would wash the bilge using either simple green or a bilge cleaner product. I would pop all the pie plates and storage compartments that connect in anyway to the bilge. Wash it then take a fan or two and force air to below decks to get drier air circulating . Ideally you could do it on a Sunday afternoon and allow the bilge to be open to the air until you use the boat next time. I picked Sunday because most folks have to work during the week. Your case may vary. If you can get the boat under cover to do this it would be good too.

In the winter I pop. The pie plates and open up my compartments in my cabin to help get fresh dry air into the bilge. Good luck.

 

[drbatts]

If your boat is on a trailer I would wash the bilge using either simple green or a bilge cleaner product. I would pop all the pie plates and storage compartments that connect in anyway to the bilge. Wash it then take a fan or two and force air to below decks to get drier air circulating . Ideally you could do it on a Sunday afternoon and allow the bilge to be open to the air until you use the boat next time. I picked Sunday because most folks have to work during the week. Your case may vary. If you can get the boat under cover to do this it would be good too.

In the winter I pop. The pie plates and open up my compartments in my cabin to help get fresh dry air into the bilge. Good luck.

good advice.

If you are seeing the slime and junk when you open your pie plates chances are that is where the water is coming from. Check the o-rings on all plates or just replace.

 

[bjflink]

Thanks for the advice. I'll try forcing air in the bilge to see if I can get it all dry. The pie plate gaskets were all replaced 6 months ago and are airtight, so thats not my source of intrusion unfortunately. And if it was, it would nt explain the wet bulkhead that is further forward. I'll dry it all out and see if I can pin point a source.

 

[ElyseM]

if you check the manual, gw recommends washing the tank area frequently. i do mine a couple three times a year. i try to do it on sunny days so the tank areas can dry out. i also coat the top areas by the fills and sender with t-9. good luck, ron

 

[bjflink]

Thanks Ron. I did read that as well. Unfortunately I'm the 2nd owner and I dont think the original owner in the 15 years he owned the boat ever rinsed them. Better late than never, I just need to figure out how to get all the sludge off in a safe way. I'll for sure use T-9 though...cant beat that stuff!

 

[ElyseM]

you might try some dawn. pretty gentle but effective. then work your way up from there. ron

 

[DennisG01]

It's probably getting wet from aft bilge water coming forward. In most boats, the drain between the fwd bilge and the aft bilge is slightly above floor height. So some of the water that sloshes forward will not make it's way rearward again. And then it's a relatively closed area so the condensation builds, rises to the underside of the deck, then falls back down. Combine that with dirty/greasy water and that would, at least, be an easy explanation for how the tank/bulkhead get wet, along with the grimy feel. If the aft bilge stays cleaner and drier, the forward bilge will, too.

Any of the cleaners mentioned can work. I'd probably spray it down and then let it set for a while. Maybe even a day or two - spraying it a couple times a day. You may be able to get most of it that way with a blast from the hose after a day or two of setting/re-spraying (to keep it wet).

 

[drbatts]

Thanks for the advice. I'll try forcing air in the bilge to see if I can get it all dry. The pie plate gaskets were all replaced 6 months ago and are airtight, so thats not my source of intrusion unfortunately. And if it was, it would nt explain the wet bulkhead that is further forward. I'll dry it all out and see if I can pin point a source.

If you just replaced the gaskets, you may also want to check the actual caulking of the pie plates. If they are original and 17 years old they may need to be re-caulked. Bilge moisture alone may cause mold growth but shouldn't be creating any significant amount of slime especially directly under the inspection or pie plates.

 

[bjflink]

It's probably getting wet from aft bilge water coming forward. In most boats, the drain between the fwd bilge and the aft bilge is slightly above floor height. So some of the water that sloshes forward will not make it's way rearward again. And then it's a relatively closed area so the condensation builds, rises to the underside of the deck, then falls back down. Combine that with dirty/greasy water and that would, at least, be an easy explanation for how the tank/bulkhead get wet, along with the grimy feel. If the aft bilge stays cleaner and drier, the forward bilge will, too.

Any of the cleaners mentioned can work. I'd probably spray it down and then let it set for a while. Maybe even a day or two - spraying it a couple times a day. You may be able to get most of it that way with a blast from the hose after a day or two of setting/re-spraying (to keep it wet).

Dennis, thanks for the info. Seems very logical! New project for the weekend! Ive got the aft bilge nice and clean, but unfortunately always a little standing water left in there due to the limitations of the bilge pump. Maybe I'll look into one of those dry bilge systems.

 

[DennisG01]

Yeah, bilges are tough to keep completely dry. Some boat styles are easier than others, but it's usually pretty tough. You can get one-way valves for bilge pumps... but then they run the risk of getting clogged. One other thing you can do, after it's clean, is to spray a light solution (10:1, for example) of water:bleach and let it sit for 30 minutes then rinse. That should kill off any remaining mildew/mold. Try to avoid spraying anything rubber (fuel hoses, sender gasket, etc), but at that dilution ratio it really shouldn't matter.

Oh... If you want to get crazy... A 12V Shop Vac or a good sponge to get rid of the rest of the water.

 

[bjflink]

Re: Slimy fuel tank grime & wet bulkhead??? SOLVED

Yeah, bilges are tough to keep completely dry. Some boat styles are easier than others, but it's usually pretty tough. You can get one-way valves for bilge pumps... but then they run the risk of getting clogged. One other thing you can do, after it's clean, is to spray a light solution (10:1, for example) of water:bleach and let it sit for 30 minutes then rinse. That should kill off any remaining mildew/mold. Try to avoid spraying anything rubber (fuel hoses, sender gasket, etc), but at that dilution ratio it really shouldn't matter.

Oh... If you want to get crazy... A 12V Shop Vac or a good sponge to get rid of the rest of the water.

Dennis, I think you hit the nail on the head. Spent some time scrubbing the tanks/bilge etc this weekend, but before doing so, I rubbed my hand across the underside of the deck in places that could not possibly get wet from anything other than condensation, and as you stated, wet and slightly slimy. Got the tanks somewhat clean, but the working area is small, and 16 years of accumulation is an uneven match for my stiff bristle brush, but I can see aluminum again nonetheless! I'll start prescribing to GW's official recommendation to rinse a couple times a year and will leave my pie plates off as much as possible to get fresh air in the bilge.

Thanks again for the tips/advice everyone!

 

[Tucker]

Not familiar with the 306 but if those hatches come up, I'd pull 'em up and re-calk. I've replaced those pie plate o-rings a lot and they still seem to leak. Like the other guys, I leave everything open during the off season to dry out. In the spring, I clean the sending units, and top of the tanks as far as I can reach and then wipe grease on the sending units.

 

[bjflink]

Not familiar with the 306 but if those hatches come up, I'd pull 'em up and re-calk. I've replaced those pie plate o-rings a lot and they still seem to leak. Like the other guys, I leave everything open during the off season to dry out. In the spring, I clean the sending units, and top of the tanks as far as I can reach and then wipe grease on the sending units.

Tucker - the hatches wont come up unless I were to remove the bench seat and tackle center. I could still re-caulk the pie plate trim though, which I intend to do.

As far as cleaning the sending units, are you actually unscrewing and lifting out the sending units to clean them?

 

[Tucker]

No,I use WD40 and a toothbrush, several applications and just wipe up the crude. I'm convinced those pie plates leak past the o-ring. Nothing getting past that caulk on the flange. I was thinking of going to the screw-ins but I don't think they sit flush like the pop-ins. I even grease up the o-ring and it still leaks. An option is to put in blank, not-quickly accessible pie plates. Still USCG approved but you have to remove the screws to inspect anything. I replaced all my sending units and the only reason I open them up is to clean the tank and sending units because the stupid lids leak. Don't forget to use that GE almond caulk.