cleaning varnish scum from fuel tank

Jen

We have a 1978 Cheoy Lee, Ray Richards sloop. The 48 fuel tank is in the keel aft of the iron ballast. The filler is on deck with a vent below in the bilge. There is a plate with about 6 bolts aft of the vent. We have a new engine, but when trying it out, we discovered we have very, very dirty fuel which is causing the engine to stall. Do you think that we will have access to the tank via that plate? Do Have any idea what material the tank is made of? It is summer, so we don’t want to pull out to fix this, but we can’t use the boat for trips until it is solved.

Thank you,
Jennifer

 

but we can’t use the boat for trips until it is solved.


I would guess you only burn 1 gph , so the "quick fix " is an aux tank set.
A couple of outboard 6 gal tanks should give enough range for a summer cruise.

The existing tank is more likely welded steel and needs to be cleaned inside and out and repainted to keep existing.Any deck leak on the tank will kill it.

Some folks have gotten away with a pro fuel polisher. Remove the top plate so the polisher can suck the fuel and return it with high pressure (30 40 psi) and volume (usually 1 1/2 inch hose).

This cleans the fuel and MUCH (but never all) of the tank, dual Raycor 1000 switchable filters will help , after the fuel is cleaned , as will a suction gage to tell you whats happening in the fuel filter.

FF

 

I agree with you FastFred. I am having this done on my boat next week for about $600! The fuel inlet inside the gas tank was getting clogged repeatadly. I have been blowing into the line to clear the gunk but this is getting old since I have to do it every hour on average when cruising. lol. It took us 4 months of scratching our heads and reading forums to finally realize it wasn't the filters, it was the inlet pipe itself inside the tank. Can't wait to see what we get out of there.

 

FastFred's idea for the short term is good. A few small portable tanks should allow you to use the engine through the summer. You can have the tank cleaned professionally by your yard when the boat is hauled in the fall. Good quality dual filters are also a good idea. Even after cleaning, there may be small deposits that will work lose or semi-dissolve over time. This becomes more likely as fuel requirements are changing, and new additives may act as solvents on old gunk. Dual filters allow you to keep cruising when one is clogged.

 

Your carbs could also be dirty and all gunked up.

If you get a bunch of acetone or laquor thinner it'll eat right thru that varnish. You can filter the chunks and recirculate the solvent by making some homemade contraption.