Oil & Fuel Rusty Fuel Tank

[Steve777]

My S470D is suffering from a rusty fuel tank. No signs of it from the outside, but the fuel filter gets clogged with rust particles every 2-3 hours of use; some very fine some coarse. No signs of water in there (aside from the rust). This past winter, I just cleaned or replaced the filter as needed, but now that warm weather is here finally, I need to deal with this problem.

Normally I would just use one of the many tank coatings that are diesel proof. Problem with that is most/all are designed for regular petro diesel, and I run biodiesel in it; 100% in the summer and less in the winter. I have not yet found a tank coating which claims it will hold up to biodiesel. In fact the two that I contacted told me outright that BD will dissolve their product.

So, I am wondering what my options here are:

1. Anyone know of a BD proof tank coating?

2. Is there a generic plastic fuel tank that could be substituted?

Suggestions?

 

[techwrtr2]

These guys claim their product works with BD. I haven't asked them nor have I used their product. Gas Tank Sealer - Gas Tank Liner - Diesel Tank Sealer - Fiberglass Tank Sealer

 

[CalG]

I can't offer anything significant to either of your questions.

But I have "mounted" a rusty fuel tank to a cement mixer, put a handful or pebbles in the tank along with a gallon of soapy water and let that run for an hour or so. Seems to do wonders on the present rusting issue.

I'm sure phosphoric acid would do as well.

 

[aircommuter]

Muriatic acid cleans rust the best. I have done the mixer also and a paint shaker machine works really well but some tanks are too big.

 

[CalG]

Muriatic acid cleans rust the best. I have done the mixer also and a paint shaker machine works really well but some tanks are too big.

It seems that when i use any acid, it always costs me a pair of jeans.
Pebbles have not caused the additional expense. ;-)

 

[Katahdin]

I've cleaned gunk out of diesel tanks that look like rust but is actually fungal growth. Are the particles attracted to a magnet?

 

[Steve777]

Good question Katahdin. Unfortunately I have already thrown out the red stuff, whatever it was; so can't try a magnet on it.

I tend to think there was some rust, only because there were some bigger pieces in there that had the look of rust flakes. However it could have been a mix, some rust and some fungus. I will check with a magnet when the filter clogs again; since I need to use the tractor again a bit before I get it fixed, I am expecting another filter clog.

 

[ultrarunner]

I've done the above with nuts and bolts on a mixer and it did a good job...

Also sealed a lot of tanks with 100% perfection until alcohol was added to the fuel and what a mess.

So the my latest is an antique car and I went and retrofitted a large oversize marine filter with petcock... it way more capacity and a means to drain...

Been driving it a lot and all the junk seems to have passed though for the most part...

 

[Steve777]

Finally getting back to this. Pulled the tank out and tried draining the remaining fuel. It would not come out the regular nipple to the fuel filter nor the drain screw. There is a layer of black/brown "gunk" in there that sealed both the floor outlets. The really odd thing is it is built up on the floor of the tank as expected, but there is also a layer of it on the top??? Feels a bit like putty.

I have been soaking and shaking the tank (outlets sealed with tape) with methanol, and that seems to have dissolved whatever this putty is. But I was curious, anyone else run into a putty like goo in their tank? I suppose it might just be from 40 years of diesel (and bio) interacting with the rubber hoses and it plating back into the tank. But this seems odd to me.

Once I get this putty/goo out of there, I can see if there is a rust problem or not...

 

[oliver28472]

That stuff got in my brother's tractor, a JX 85 Case before he bought it. I was the first one to really put it to work, bush hogging way back behind my house one night. A local mechanic rigged up a temporary fuel tank and took the tractor to his house, removed the plastic tank and power washed it out. The tractor had been sitting unused for a year or two. The fuel jelled up.