Gas Tank Rust

[siteunseen]

I did spray mine inside and out at a car wash. My Dad put a piece of chain and some old nuts and bolts in his truck tank when we did it a month or so ago. It had some terrible rusty flakes in it, '55 Chevy with a long skinny tank behind the seat. Tape all the openings up but when your through, before the coating dries completely, blow all the tubes clear with an air compressor. That clears out the pick up tube. I chose to do 2 coats but in hindsight the acid did such a good job I needed just 1. If yours comes out as good I would pour the whole qt. of Red Kote in and roll it around by hand to coat everywhere then hang it so it'll drain out, seems like there where small holes around the perimeter of the tank, maybe 4?, where it's welded together that work good for the hooks on the straps. That stuff dries fast so turn off your phone. When you have drained out all you can, most through the fill hole, that drain plug hole isn't big enough for this stuff, put it in the sun and keep rotating it. I wish I had left mine resting on the top. Some of those channels going to the drain hole will hold it causing thick spots. After rinsing all the soda out with your hose pipe I would put at least a half of a qt. of denatured alcohol and slosh that around. It will evaporate all the moisture from the tank and hit it with a leaf blower and then Red Kote. Get a throw away funnel and cut most of the stem off, it'll come in handy when pouring the stuff in the tank. If your smart enough to keep your pool up with acid and baking soda this will be easy. There's just a lot of steps to get it right.

Edited October 30, 2012 by siteunseen

[Bonzi Lon]

Here is a write up I did years ago.

http://www.classiczcars.com/forums/thread21619.html

Bonzi Lon

[bhermes]

I think I am ready to start the process. A lot of good information and direction.

I am going to initially spray the tank with water, maybe at car wash. I will let dry for a day or two and then seal openings and apply the Muratic Acid/Water mix. I will leave this in the sealed tank for about 24 hours. Drain out the acid. Then follow up shortly after with the baking soda. Drain out baking soda. I will let the tank dry for a day or so, reseal, and then apply one coat of Red Kote. I will then blow air into each of the opening (prmarily the pick up line). I will wait a week or so before putting in fuel.

Please review and make suggestions. Not sure how long to wait before blowing with air to prevent the pick up line from clogging.

Again thanks for all the help. Hopefully I have read the info correctly.

[240260280z]

Don't leave acid in too long.

Following Muriatic Acid with rinse then Phosphoric Acid soak is great to kill future rust

Edited October 30, 2012 by Blue

[bhermes]

Blue, are you talkling about 30 minutes or so for acid? Also, first I heard of Phosphoric Acid for this. Should I do this after the baking soda?

All, I am a little cocerned about my sending unit. My gauge has not worked since I have owned the car, 1 year. It is on about 1/2 tank. The sending unit was rusty and I have cleaned up a little. What would happen if I reconnected the unti outside the tank and moved the float up an down? The windings look pretty good. All connections also look good. Float may have been stuck.

Thanks.

[240260280z]

Yes ~ 30min to 1 hour for the Muriatic (agitate it often). Then rinse well with lots of water then hit it with the phosphoric for 30min to 1 hour followed by a rinse then dry. No need to neutralize the phosphoric as it does not flash rust like the muriatic does.

Only use the baking soda to neutralize if you skip the phosphoric.

[siteunseen]

I think the mixture would determine the time left in the tank, acid to water I mean. I think I did 50/50 for less than an hour but mine wasn't too bad and that's pretty strong. Did you ever get a good picture?

[bhermes]

I will try and take some better photos but here is what I currently have.

I just had phone camera with me at the time.

I have since removed the sending unit. Still looking for suggestions in regards to functioning and testing outside of tank. If I could find one for $40 like one of the posts mentioned I might consider but only thing I have found is $250-400.

[Mikes Z car]

On my sending unit I checked the continuity between the two posts with an old analog multimeter on the resistance range with a needle instead of a digital display. That way as I slowly swung the tank sender through its range I could more easily see if the resistance smoothly varied between extremes of resistance (I measured 11 (full) to 80 (empty) ohms, others have measured closer to 8 on full). If the meter needle went to infinity frequently indicating an open circuit then I knew the connection between either the coil and the wiper arm or between the wiper arm and the post it connects to was not as good as it should be. I did the resistance checks using alligator clips to keep everything connected. My unit needed help, so after I sanded the coil of the sending unit (and soldered a wire from the wiper arm to the post it connects to) I tested it in the car by connecting it with alligator clips to the wires it normally connects to and then swung the float slowly through extremes of motion remembering my pertronix (back then) so as not to leave the key on too long for testing. Here is another post on adding a wire:

http://www.classiczcars.com/forums/showthread.php?t=35258&p=318623&viewfull=1#post318623

[Mikes Z car]

bhermes,

In looking at the pictures of your tank, your float appears to be turned 90 degrees to the way mine was laying on the bottom of my tank assuming your two pictures showing the float are upside down as I am perceiving them to be. Your tank looks different than mine so maybe your sending unit is supposed to look that way.

Anyone know if some Z car tank floats rest an end on the bottom of the tank as bhermes' gas tank pictures in post #44 seems to be showing?

[CW240Z]

I used red kote because of the price difference, $20 qt. at O'Reilly's or off ebay, I've put about 1,000 miles on mine since doing all the work and the glass filter I have right before the fuel rail has never had the slightest bit of color as in pink or reddish looking fuel in it and I check it every time I drive the car. I'm happy with what I did and I'd never done anything like that before.

I also would suggest the red kote product. I've used it on two separate tanks with great results.

Chase

[ZCurves]

Don't forget to treat the inside of the gas lines on the tank with the acid and then again with what ever sealant you choose. Make sure to have compressed air to clear the lines after you have put sealant through, this will make sure the stuff doesn't clog the lines.