Sealer for fuel sending unit screws ?

What is the best sealer to use on screws for univrsal fuel sending unit and compatible with the ethanol based gas ? I am instaling a new sender in a new aluminum fuel.

 

A thin plastic washer on each screw?

 

I've never had a problem with the "sender unit" leaking fuel because the gasket between the tank and the sender seals things, also because it's on the top of the tank and I stop filling when the gas pump nozzle shuts off.

If the screws are short it might be easier to cover them with a puddy or fuel tank sealer over the top of them.

Why are you worried about the "sender unit" (top of the tank) leaking ?
Do you overfill that much, if so you should be more concerned about the fuel tank vent line location.

 

Permatex #2 non-hardening sealant would be my choice to do the job. Dip/coat the threads with the sealer when installing.....presto!..no worries.

Ray

 

I've used Permatex #2 also. But I was using sheet metal screws in a home made tank. Worked well.

 

My friend who built and pressure tested the new tank said there was some slight bubleing at the screw holes. You have a good point about overfiling. I was just concerned about the fuel sloshing around. Not really using a vent line as the tank will vent when filling through the cap opening. Filler neck is 3 inches tall, straight up on top of the tank. Tank is 14 gallon rectangular box style of .090 thick aluminum the welds are tight. I was looking for a sealent to put on the threads. My friend also mentioned a sealer for inside in case a welded seam cracked due to vibratioin. Not so sure a sealer would stick well on the aluminum surface and I am concerend about it preeling off in the long term and messing up a new tank.

 

You need a tank vent of some sort, either a vented cap or a small tube routed outside the body, or you wll eventually come to a halt and/or collapse the tank. Venting through the filler when refilling the tank is one thing, allowing air in to displace the fuel being used is another matter altogether.

As for a tank inner coating, I would not do that as I do not trust that they are in fact impervious to current fuel chemical makeup. Either your tank currently doesn't leak or it does. If it does, fix the leak. If it doesn't, leave well enough alone. If it cracks later, tank sealant won't stop that kind of leak. My $.02

Ray

 

Thanks guys for the coments. Permatex #2 I will use on the screw threads for final instalation. Tank welds do not leak now so I will not use a tank sealer product in the tank. I have a vented cap for the filler. So I think I have all the bases covered.

Any other comments or input is welcome.

Steve

 

Does your vented cap vent "out" or "in"? I have both vented cap[out] & tank vent line [in].... just a thought... dave

 

ditto- I use it on everything.

 

Isomode mount the tank -

bolt
washer
rubber
tank flange
rubber
tank foundation
lock washer -------
nut --------------- or replace both with a NyLok nut

Remember to add a good ground wire.

 

2old2fast I am not sure wich way the cap vents but it is new and camewith the filler neck as i recall. My guess would be it must vent in when thecap is installed. venting the tank should be ok as baffles do not go to the top of the tank and it will vent when filling with cap removed. Fordtudor37 I planned on hanging the tank on straps/ with an angle bar style rectangular box support under the bottom, sort of a cradle support with a rubber strips for a cushion and to prevent electrolis between steel and aluminum. Guess i should have got the isomode from the place I worked ( navy yard) but retired now going on 5 years. Fordtudor37 do you think my mounting idea would work ok ? Yep can not forget the ground wire.