The Stovebolt Site Forums The Shop Area General Truck Talk Gas Tank Cleaning - (Rotissori Style)

I am about to remove my gas tank and clean the crud out. I plan on putting a couple of quarts of pea gravel in it and rotating around using a rotissori, then removing the gravel. Maybe I'm paranoid but I plan on counting the pieces of gravel going in and coming out. My question is should I use water with this idea, or another liquid (hydrogen peroxide maybe)? Is this overkill? Thanks in advance for your feedback.

Rance

Rance in the past I have just used a steam cleaner, set the tank in the upright position, put the steam cleaner wand into the tank filler neck, tie the handle to keep it open & let it run for 45 minutes to an hour or when the tank gets hot and the water looks clean coming out of the filler neck. shut off the steam cleaner and dump the tank out, remove as much water as you can . The heat should pretty well dry the rest of the water out

I don't see the need to count the number of pebbles unless you have WAY too much time on your hands. As you're emptying it, you'll know when they're out when it gets quiet. You'll know.

I've cleaned numerous gas tanks and I've used (wonder of wonders) gasoline. I've sloshed a quart around inside and poured it out until the loose chunks stop coming out. Your "rock tumbler" method will probably scour the inside a lot more thoroughly, but I've never had any problems cleaning mine with gas. If I were going to use your method, I'd use water as the liquid medium.

The steam cleaner idea is a good one, too. To dry it, let it sit in the sun for a day or so.

There are several companies (Eastwood is the first one that comes to mind) that sell products for painting/sealing the inside of a tank. You might want to look into that, once you've cleaned it out real well.

I'm gonna have to do the same sort of thing with my Model A, but it's a cowl tank and I'm not tearing it down far enough to remove it. I was able to look inside it the other day with a flashlight and I guess I'm lucky cuz there's just a slight layer of rust. But I'm gonna run gasoline thru it while agitating it to get the majority of the rust out. (I hope.) I'll be draining it thru a glass sediment bowl so I can watch what comes out.

Why not try nuts & bolts? If they don't come out easily you can always use a magnet. Also, if you have a tractor- you can strap the tank to one of the the large rear wheels and drive around for a while!

I dont know about using creek gravel but I have use glass marbels. They dont spark so any fluid you use will be ok. I have used chemtool carburator cleaner. The gallon can. works well but use a well vented area. I did this one time on a motorcycle tank and straped it to a paint shaker. CLEANED THE CRUD OUT OF IT!!!!!

As a side note, the glue you pour into the tank will work most of the time. I had a bad reaction one time, or maybe some old sealant but it stayed for a month or so then started comming off in sheets. Had to remove the tank, cut it in half, scrape out the sealant and then while apart cleaned out the rust. Welded the whole thing back together filled it up, found a leak. And then replaced the tank. Live and learn.

Used the Eastwood system, so far so good.

I have cleaned numourous motorcycle tanks using this method.

Poured some carb cleaner in to get the varnish out. Slosh it around for a while, let it sit and then slosh it around some more.

If there is rust or heavy crud in the tank, I raid my 100 years drawer for some nuts and bolts. I fill the tank about half way with hot soapy water and the nuts and bolts seal it up and start rolling it around in on the nice grassy lawn (I like the tractor tire idea better). I then drain and flush the tank. If I'm going to treat and seal the tank I go ahead and do that. If I'm just going to return it to service I pour in some wd40 and slosh it around to prevent flash rust before the fuel gets in it.

Just a little update on this. I got a wild hare and decided to use some compressed air to blow out the Model A's gas tank. Now ya gotta remember that it had been sitting for quite a while before I bought it...matter of fact, I found what seems to have been a mouse or squirrel nest in the block's water passages. What a mess.

Anyway, when I stuck the air nozzle into the gast tank filler, I was rewarded with a cloud of yellow-orange dust that looked like a poison gas attack. I let it blow away and repeated it...and repeatedand...well, you get the picture. I think I've blown most of the powdered iron oxide out of it now. But it sure made a mess. I think I better rinse it with water before I try it with gasoline. What's it gonna do? Rust? I'll have to try the WD40 thing after I rinse it. That sounds like a real good idea.

Ahhh...the fun of old trucks.

I'm gonna have to do the same sort of thing with my Model A, but it's a cowl tank and I'm not tearing it down far enough to remove it. I could be wrong but some freinds of mine say in order to properly paint the A you must remove the cowl and paint it first. Then do the other body work and paint the rest of the car. As I said I or they could be wrong.
Hell i didn't consider that you may have already been down that road.

I've used a handful of ball bearings and the power washer before works ok. Also dried it with a few shop rags and a blow gun with a long tube end on it. The sealer thing, I naver had any work well yet, maybe the stuff was to old or it was to cold to use it.
Raycr

A simple shake of the tank will tell you if you have all of the gravel out. Commercial gas tank cleaning/coating kits use phosphoric acid (the same stuff that's in soda pop) to clean the rust & varnish. I used muratic acid because it's cheaper and easier to get. Be aware that Muratic acid is bad stuff and it Will burn you and eat your clothes or anything else it touches so be careful if you use it. About 5 minutes of sloshing the acid around in the tank is enough. I then poured a couple gallons of strong soda water in to kill the acid, rinsed the tank good, let it dry overnight with a fan blowing in the filler neck and coated it with Redkote. Personal experience has shown me that those who have had problems with quality tank coatings haven't followed the mfgrs prep instructions.

I had actually done the gravel thing 35 years ago with a motorcycle tank. I put them in the tank and put the tank in my wife's clothes dryer w/o heat and stuffed pillows around it to secure it. It turned out GREAT. Thought a variation of that might be worthy for the truck.

Lots of good ideas and advice above. Thanks folks. I'll let you know what I do. If I build the rotissorie, I'll take some pics for ya.

I can see how that would be the proper way to do a restoration. But mine's on its way to becoming a rat rod (of sorts) and at this time I'm leaving the unpainted surface on the cowl, doors, fenders, etc.

I got it out of the garage tonite and flushed out the cooling passages in the motor. The radiator's at the shop havin major surgery.

I'll flush the tank out tomorrow. I "ran out of gas" (physical energy) tonite, so I left it in the driveway with my Ugly Truck protecting it:

http://www.chevyasylum.com/29modela/29modela_0326r8.jpg

I used the POR-15 cleaner and sealer on mine. Worked like a charm.

-Rich

I used the Por 15 treatment kit. A little expensive and I spent the entire afternoon following the procedures. Just yesterday I looked down in the tank of my original 37 tank and it still look fantastic after 6 years.... I am not recommending anything..just what I tried!!

I just flushed my Model A's tank today. There was a lotta reddish water comin out of the tank at first, but after a while it cleared up...and left a mess on the driveway. I guess I'm gonna have to do some scrubbing or mama might just pitch a fit.

I got a lot more done on that critter today: Carb, plugs, starter, water necks installed. Also got the inside of the bed and the frame rails painted so I can install the new bed wood.

I dumped a few of handfuls of used,broken,carbide cutting inserts and a gallon of water in mine and after a few minutes of tumbling the entire tank was shining like brand new. It also had a nice bite for coating. Any machine shop should have buckets of used inserts laying around.

Curt B.

Well... I finally got around to removing the tank this eve. Took out the sending unit/sump. The sending unit has a good amount of barnacles on it. I know that it still works so if I make sure I don't get any sand in it, would it be ok to sand blast it lightly to get the barnacles off of it? Maybe emmory cloth would be a better idea, I just know there's some cracks that sand blasting would be easier than emmory cloth.

The pickup sure enough has what looks like a flour(ish) coating on it about a sixteenth thick. It is VERY soft so I don't understand why that would prevent fuel from passing through it. I guess what I'm looking at is after fenagling(sp?) it to get it out and I scraped some of it off. Before I removed it, it was probably completely covered.

So what's a tank like ours come with on the inside from the factory? If I thoroughly remove the rust, what's wrong with just coating it with WD-40 and then reassembling it? Unless I let it sit for months without driving (which I don't), then will the rust return quickly? How's this different than what's in the newer cars? Thanks for your comments guys & gals.

Rance

[Edit:]Oh, and one more thing. I took the two nuts off so I could remove the filler neck and it seems to be glued on. Is there a trick to removing this? Should I even be messin with this?

LMC has a new tank and sender for less than $200. That would eliminate any future problems concerning the fuel system. Just a thought,
Scott

A bare tank will rust if not coated. WD40 will wash off with the gasoline. Your sending unit should be OK if you keep the rheostat clean.

I had varnish type crud on the bottom of one of mine. I took regular carb cleaner and poured it in the tank and let it sit for a few days. Then before I drained it, I put in a bunch of 3/8 nuts and bolts. I shook it around a bunch and then drained it back into my carb cleaner pail through my strainer bucket. It took all the old crap out and cleaned my nuts and bolts too. I just pressure washed the inside of the tank, blew it as dry as I could and then took some wd40 and poured a quart in it and shook it to coat all the surfaces and remove any moisture. drain it and away I went.

I also heard of the "coating" on gas tanks flaking off and causing trouble. I used nuts and bolts in my tank. Shook them around and after that I bought a quart of metal "Prep and Primer" acid from Home Depot. Sealed all openings in tank and sloshed the acid around. Rinsed it with water and let it set in the sun for a day, in Phoenix summer sun it doesn't take long. I filled it with gas within 3 days and has been great ever since.

You guys are scaring me to death. Gas tanks can blow op like a bomb. I saw a picture of a gas station that had a gas tank blow up. No more gas station. I will pay some one to do a professional job on a gas tank before I take a chance on blowing my head off.

Most radiator shops will also hot-tank and clean gas tanks.

Thanks Josiah, I'll consider that. I havn't made much progress. Actually, NO progress to speak of. I let it air out in the yard for a couple of days. It's been in the garage for a week or two now continuing to air out. Sure can't wait till my back stops hurtin & other things stop breaking so I can get back to 'Ole Booger'. Life sure is busy when you're a Mr. Fixit.

Latest issue of Hot Rod Magazine shows how to clean out a gas tank. The one they are doing is from an AD truck.

Finally an end to this story. About a week ago I put about a gallon or more of pea grael in the tank, strapped it to the old fashoned swing in the front yard and began rocking it back and forth. I spent 15min on each side and then spent another 15min in the upright position. You can guess what the rocks looked like when I poured them out. Red as could be. I followed that up with a water rinse. Then I poured a quart of oil and about a gallon of gasoline in and made sure I coated all inner surfaces with that.

Had a bit of trouble getting the filler neck reattached to the rubber boot but was successful. Took it out around the block the next day and about 18mi a few days later. NO MORE STARVING THE ENGINE of gas. Now on to bigger and better things. Thanks again for all your suggestions and help.

hi , i have done loads of petrol tanks, and the last one i got half a bucket of flaking rust out of it, i used some very light taps with a small rubber hammer first, just to loosen any heavy crap, then shake that out,then block any holes with rubber bungs etc,then fill with hot water and a mix of caustic soda,leave a while, then drain out, then use one of those kits from eastwood, and follow instructions, i have had no trouble at all with these kits , it can be messy, but it sets like concrete, and you waste a lot, what i drain out, i use on the outside of tank with a brush, especially round any seams, then refinish outside of tank as desired, just remember to keep any fuel feeds and drain holes clear as you go along, and once stirred it is not reusable, as it sets. keep tank full as much as poss with fuel and if laid up for along time add there gas preservative, which comes in there kit, hope this might help , steve, uk