Fuel Polishing and Sealing the Sender

[Tim S.]

The sender unit on my 1999 20' Osprey corroded and eventually leaked seawater into my gas tank and eventually fouled my carbs. I've been using an external tank for a couple of seasons with no issues.

1) There is a fuel polishing company in my area that claims to be able to clean the gas tank and return the remaining gas to high quality. It costs about $600. I'm concerned about the reliability of this method. Does anyone have experience with this?

2) I have replaced the old sender. The screws for the new sender don't completely synch down the unit. It's a poly tank (~40-50 gallons). Any suggestions about how to seal the unit to prevent any water from leaking in (silicone, liquid gasket...)?

I appreciate any suggestion!

Tim

[boatnamesue]

It costs you $0 to siphon out the fuel yourself.  And being it’s summertime, letting tank “dry out” for a few days will allow any residual water in tank that wasn’t siphoned out to evaporate. 

Sealant won’t stick to poly.  But if the screws are screwing into a metal backing plate for instance, sealant will do the job.  Of course you could get shorter screws. 

[Tim S.]

Thanks Jason. I already tried the siphon the tank. It's very hard to get complete evacuation of the contaminated gas. Contamination in the tank is the bigger problem. The carbs get fouled by a precipitant that makes it past my filters. It seems to me the tank needs to be cleaned. BTW the deck is sealed so removal is not a great option.

[boatnamesue]

You can try using a siphon generator to pull out the remaining fuel/water.  I believe You can rent one at Home Depot/Lowe’s.