My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: GunnersWillys on November 14, 2023, 10:36:41 AM

Title: Protecting Gas Tank So It Doesn't Rust
Post by: GunnersWillys on November 14, 2023, 10:36:41 AM
Greetings.  '583B owner here.

I replaced my fuel tank probably 10 years ago.  I padded underneath it with some rubber to hopefully stop a hole from rubbing in it as it is used.  That actually seems to have worked.  But recently I've had a really strong fuel smell that turned into the gas tank magically emptying.  Finally determined it was leaking, so out it came for inspection and hopefully repair.

Nope, way too much rust.  Probably about 20% of the bottom shows rust damage and bad pitting.  Not repairable, so I ordered a new one.

This really shouldn't happen, but thinking about it, when the floorboard gets wet the tank just sits in a puddle of water.  How can it not rust? 

Is there a best way to mount this thing so it dries out underneath?  I ordered the felt kit and will use that this time, unless someone has a better suggestion.  Thanks.
Title: Re: Protecting Gas Tank So It Doesn't Rust
Post by: Rus Curtis on November 14, 2023, 11:51:13 AM
There were strips under the tank to keep it elevated (and prevent metal to metal contact - including the hold down strap on the top).  The water can't be stopped, e.g. rain, stream crossing, hose-down after a muddy trail, etc., so the next best thing is to give it a way to drain.  The holes in the side panels do most of the work, but as you've found out, some can get trapped under and around the tank.  These strips allow the water to drain from the nearest hole, including the round holes in the floor pan for access to the fuel tank fittings.

The tank that came with my jeep had many holes (swiss cheese) that developed, even after I added rubber strips to keep it off the floor pan.  Back then, I had none of this information.  The only fix then was to replace the tank.

Here's a good image of what it looked like:

https://cj3a.info/tech/gastank.html

Notice the strips are webbing.  I've read that these anti squeak strips were soaked in tar or asphalt to enhance their performance. 

I bought a strip kit from Beechwood for my new replacement tank.
Title: Re: Protecting Gas Tank So It Doesn't Rust
Post by: Chuck W. on November 14, 2023, 03:35:57 PM
I worried about the felt or webbing becoming soaked with water, so I found some neoprene rubber, 1/4" thick x 1" wide x 10' long and cut it to fit under the tank. I laid it in the same pattern shown in Rus's drawing and I hope it will allow any water to escape at the ends.
I also make a habit of removing the tank every couple of years to clean and repaint, if necessary. It's a bit of work, but it's the only way I can see to keep the rust at bay.
Title: Re: Protecting Gas Tank So It Doesn't Rust
Post by: GunnersWillys on November 14, 2023, 05:49:16 PM
Okay, thanks.  KW had that same diagram on their tank web page.  I'll just follow that pattern with the felt, maybe reuse the rubber tubing I had there for chaffing.  And drill another hole or two in the floor.  One more can't hurt!