Fuel sending unit question

[faqinshiet]

Hey guys,
I have a fuel sending unit that had a bunch of corrosion on it so I took a wire brush and was able to scrub 90% of it off. Question is does the metal hanger part need a coating or something to protect it from corrosion from the gasoline? Or will the bare metal be fine in the gasoline? Thanks for listening to my stupid question!

Richard

 

[prove_it]

It will slowly corrode I believe. I'm sure you can find some fuel safe paint to cover it up.

 

[GSTwithPSI]

You can coat the exterior with paint. The hangar part (part that goes into the tank) should be bare though. Gasoline won't corrode the sender. If moisture gets into the tank though, that will corrode the bare metal hanger. You need to make sure that your tank isn't getting an excessive amount of air or water in it. Make sure the vent lines are routed properly, and there are no holes or leaks in the tank. Sometimes the tank seams can even leak, and allow moisture in.

Also, don't let the car sit for a long period without a full tank of fuel. If the car is going to sit for more than a few days, fill up the tank, and there's no way the sender can corrode. Again, the bare metal sender submerged in gasoline won't corrode. You may get that varnish looking sh*t over time, but definitely not corrosion.

 

[G]

The interior of the tank and the sending unit are not bare metal. They are a type of fuel resistant cadmium or yellow zinc plating. Once the coating fails then the metal will corrode. The most common areas that are first to fail are riveted areas and welded areas like the baffles.

 

[GSTwithPSI]

He said he wire brushed the sender, so....yeah, it probably is bare metal at this point.

Regardless, the sender may be coated in zinc, paint, sh*t, or whatever. My point still stands, and that is steel (which is what the sender is made out of) will not corrode when submerged gasoline.

Aside from rust, I'm not sure what other sort of corrosion takes place inside a fuel tank. Rust is caused by oxidation, hence, you need oxygen to cause rust. Water and air facilitate conditions under which oxidation can occur, which is why I suggested checking the tank for leaks. Varnish and types of buildup can be common, but not corrosion.

If the sender and tank are clean and free of leaks, you shouldn't need to coat the tank or sender with anything. If you do have to coat them, they make special coatings to seal the components. You can use Red-Kote or something similar to condition parts that will see prolonged exposure to gasoline.

 

[faqinshiet]

Thanks! Yeah I will take a look into red-kote. Gas tank is being extensively cleaned by a radiator shop.

 

[GSTwithPSI]

I had problems with the tank on 1813. It was in the last few pages of the build thread, so you can look there for reference ---> click. Radiator shops and such typically seal the tank after it is hot tanked. It all depends on how shitty the inside was, though. The shop that did mine cleaned it and sealed it.

 

[faqinshiet]

Oh yeah! That's about as bad as mine is. They hot tanked it now three times and possibly look at using a sealant.

 

[G]

If you can find someone in your area to do it, the best coating is a hot dip galvanized/ zinc coating. The fuel tank will then outlast the car /ubbthreads/images/graemlins/rofl.gif Plus since the fuel tank is dipped the coating coats all the nooks and crannies inside the tank.