Rusted gas tank

Wondering if anyone has a good way to deal with a rusted gas tank. I remember someone telling me you can buy a paint that you slosh around to coat the inside and it will stop the rust from flaking off and causing fuel supply problems.  Seems too good to be true.

What I usually do is toss in a handful of nuts and bolts and roll the tank around for a while. If you do much four wheeling, throw it in the back of your truck for a week or two. This gets most of the rust broken loose and you can shake the majority out. You can then buy sealer (Red Kote, Kreem, whatever your choice may be). I personally like Kreem, never dealt with any of the others. Just follow the directions and you won't have any problems. I did this to the tank on my Farmall H a few years back and no problems so far. There is a video on youtube of a guy and his way of doing it (http://www.youtube.com/watch?v=eVZvjdQT3ks) but your mileage may vary.

Daniel

This is an earlier post by a forum member.

If it's rust-

Buy a pound of red devil lye, or liquid plummer dry powder (READ the can and make sure it is almost 100% PURE LYE)   

Fill the tank with water. Add 3-4 tablespoons of lye for every gallon of water.

DO NOT EVER EVER NEVER NEVER DUMP THE POWDER INTO THE TANK BEFORE THE WATER! IT WILL GO BOOM IN YOUR FACE WITH CAUSTIC FUMES AND POWDER!!!!!

get a piece of scrap iron from your pile of junk, preferably a rod.

hook your battery charger POSITIVE to the scrap steel, and NEGATIVE to the tank. Do not let the scrap steel touch the tank. shim it in the gas cap opening so it doesn't touch. Polarity is crucial! If you hook it up backwards, your scrap steel will come out shiney and rust free, and your tank will have big holes in it!

I'm curious about one aspect of electrolysis vs. sealcoating. Electrolysis removes material (rust), thereby potentially thinning the bottom of a gas tank. Does sealcoating require that all of the rust be removed, or just the loose material?

I used this information to build two electrolysis tanks, one is 250 gal., works great for fenders and wheels.  Have a battery box in one now.  I drain the big one over the winter.  I use sodium chloride which will remove paint also.

I forgot to say use a chain a few links long, beat that around to remove your rust until your are happy with how clean your rinse water is. Then use the product from carquest or something similar....

Follow the above instructions for de-rusting and then buy a "motorcycle tank kit" from POR-15. If you follow the directions, your tank will not need attention again. With any of these products, tank prep is the key. I like the POR-15 kit, it includes degreaser and an acid etcher, so the final coating has the absolute best chance to adhere.

I've used two different brands of sealers AND electrolysis, and while both work, I've been most satisfied by tumbing them out.

I take a can of random bolts and nuts, dump 'em in, and pour in some mineral spirits or kerosene.  Then I seal it all off, and ratchet-strap it to the wheel of a tractor and go for a drive.

The reason why I dislike sealers, is that you're placing material IN the tank.  IF it doesn't initially stick, or if it becomes unglued, you'll have exactly the same problem as now, but worse.  I learned this from experience- one that I did, and some that others (supposedly professionals) had done.  It works, but it only works well and lasts, if it is absolutely perfect.  That being said, I will NEVER coat another fuel tank.

Using electrolysis to clean the tank works, but only in the areas where the anode has good path to desired surface metal.  You oftentime can't see the inside of the tank well enough to determine if you've gotten all the crud, furthermore, areas that are in the shortest (electrical) path through electrolyte are most cleaned.  I like electrolysis for cleaning castings and parts where I can dip and place anodes to focus cleaning in the tough areas... but don't like it for inside cavities where I can't inspect the progress.

What you really want to do, is  just get all the loose crud out of the tank... you're not trying to prepare a sterile environment... when cleaning a fuel tank, any result that'll give good running and not plug up the sediment bowl or bowl inlet is an acceptable result.

And another option- I cleaned out a tank in a Farmall 656 recently.  It failed to start about 15 years ago, they tinkered with it a couple of times, and then resorted to using a different tractor, and there it sat.  Tank was yukky ugly nasty, so I yanked carb, gave it the proper cleanout and rebuild, hooked up a rubber hose and strapped a 6-gallon boat tank to the hood to get 'er goin' again... then I trained focus on the tank.

First, the 656's tank is big, and not easy to yank out, so I dipped the tank to find out how much nasty old shellac was in there... this told me where the shellac stopped, and the rust started.  I found some 1/2" ball bearings and dropped 'em into the bottom of the tank... lots of crud down there.  Then I took the 656 for a ride through the valley.  Got back, removed the sediment bowl, and (after shoveling rust out of the way) it flowed the old crud out into an oil-drum.  I put a piece of old T-shirt in the funnel to catch the worst of the rust (the old crap WILL burn, so it went into the waste-oil tank).

Once empty, I took a pressure washer and blasted the inside of the tank.  To get access, I removed the fuel cap AND the fuel gauge sending unit.  My HP sprayer uses common 1/8" npt pipe as the wand, so I got an extra piece and bent it just under 90-degrees to give me more angle options.  Every surface I could hit, I hit.  Eventually, I had a huge pile of rusty crud in the bottom of the tank, so I took a piece of 1" PVC conduit and duct-taped it to the end of my shop-vac hose, and sucked all the crap out.  With tank dry, I took it for another drive (good day for a tractor ride, anyway).  Again, I had a big pile of rusty-dusty-crap down there, so shop-vac'd it again.  Rinsed it again, more crap... vacuum'd again...  finally, I'd rinse, and it wouldn't dump rust.

I put the sediment bowl and sending unit back on, and filled it with water, then took a sawzall, removed the blade, put a piece of cloth on the foot, and put it against the exterior of the tank, and buzzed the tank.  A LITTLE more crud came loose, but not much.... so I drained it, vacuum'd it out, and installed a new sediment bowl.  I also added a little more 'stick' to the inlet tube of the sediment bowl, so that any other crud taht ended up on the bottom wouldn't drop in and plug it.  Then I filled it with high-test gasoline, hooked up an inline-filter downstream of the sediment bowl, and hooked it up.

I left the big ball-bearings in there for several months, regularly dumped the sediment bowl and backwashed the filter a few times, eventually ran the fuel level down (656's hold a LOT of fuel!).  When it finally reached the tube, I yanked the sediment bowl, drained it again, rinsed it, vacuumed out more crap, and removed all but three of the ball bearings, cleaned out the sediment bowl, and filled the tank again.

I've emptied the sediment bowl a few times, and it's been to remove moisture... but she's running clean now.

Important to points to know: 

Do NOT vacuum out the tank unless you've rinsed it well with water... most shop-vacs draw the vacuum'd air through the motor for cooling, and they're brush-type motors, so there's a possibility that fumes could catch on fire.

Filling the tank with water completely displaces all fumes.  Although the tank, after filling, may smell 'gassy', what you're smelling is shellac, additives, and other non-volatile residue.

Filling the tank with fuel displaces all air, hence, prevents oxygen from reaching the tank surface.  Don't rinse the tank and let it dry any more than you have to, because it will expose the tank interior to oxygen, and cause more corrosion.

Filling the tank with high-test gas will cause condensation and stray moisture to fall to the bottom of the tank (it's heavier).  This moisture will wind up in the sediment bowl, along with any particulates.  Dumping the sediment tank often is the key to cleaning 'em out the best.

Vibration is your friend.  When idling or working the engine, let it run at a speed where it shakes... this will help knock all the crud loose.  Park the tractor on an incline where the sediment bowl is at the lowest point, so crud will migrate in that direction.

Lol, I enjoy watching your videos, been subscribed for over a year now. Keep em Coming. On the "your mileage may vary" comment, I was referring to people with luck like mine - if it had been me, that kubota would of been half way to Florida by now with me chasing after it. But then again, I have a fresh 'shiner from pulling t-posts today so perhaps I am a bit of a klutz...

Daniel

Lanse wrote: LOL!! Thats me... And thats my video!! Im glad you liked it... It seemed to work pretty well for me :-) kyhobbyfarmer wrote: What I usually do is toss in a handful of nuts and bolts and roll the tank around for a while. If you do much four wheeling, throw it in the back of your truck for a week or two. This gets most of the rust broken loose and you can shake the majority out. You can then buy sealer (Red Kote, Kreem, whatever your choice may be). I personally like Kreem, never dealt with any of the others. Just follow the directions and you won't have any problems. I did this to the tank on my Farmall H a few years back and no problems so far. There is a video on youtube of a guy and his way of doing it (http://www.youtube.com/watch?v=eVZvjdQT3ks) but your mileage may vary. Daniel

  Hello Donald    I agree with a lot of the suggestions here, but think about these.  The problems with gas tanks is that crud gets into the top of sediment bowl BEFORE the screen in the bowl, some new sediment bowls have a stub / standpipe in them, but water/ condensation lays in the bottom of the tank.  The cheap easy way to fix it is find a 3/8" pipe plug, coffee can and a piece of fine brass screen rolled like a cigarette, remove the sediment bowl assy, let some gas run into the can install the pipe plug, clean the sediment bowl assy, Teflon seal the threads, install the screen into the top fitting, crimp the top, remove the plug and reinstall bowl assy.  The dirt/scum can't get into the top inlet.  Every  restoration, fuel problem gets a screen. We buy  brass screen from McMaster Carr