What's the best way to remove rust from your diesel fuel tank? Flush it out? Possible tank liner? Thanks
Yair . . . I have seen a D6 tank sealed up with a bit of diesel, a few pounds of four inch nails, a few hands full good sharp gravel and strapped to agi for a few hours, it was noisy but they reckoned that it worked. I mostly used to water them up and take a big panel out with a slit wheel so I could get in there with a needle gun and grinder . . . with a TIG its not much trouble to reweld them. Back then we cleaned them back to shiny as possible and left it at that. There was no coating I would trust to not flake and cause further trouble. There are probably products these days designed for that application. Cheers.
Well, how many gallons? I've had good luck with a little chemistry class. just did my 40 gallon truck tank with good success, remove the tank and get out as much loose stuff as possible, pressure washer and good strong soap to remove all diesel residue, one of those angle heads for the nozzle works great, blast everything out. Mix up two cups of sodium carbonate in 5 gallons of water, seal up all but one big hole in tank and then pour into tank, add another 5 of clear water and repeat until the tank is full. If you can find a spot where the tank can be completely full, that's perfect. Now take an old time battery charger on 15 amp setting, ground lead to the tank body, + lead to a piece of threaded rod that reaches well into the tank, often I'll use wooden paint sticks to keep the lead from shorting out. You'll see a little wiggle of the amp meter and just let it run, a couple times a day its good to shut it down, clean the threaded rod electrode, add more water and plug it in again. A big tank will take a couple days and the process can't run too long, won't cause harm if you run it a day over. You might go through a couple threaded rods, replace them when they get thin, I usually use 1/2 inch. Flush and rinse and pressure wash the tank again, all the rust spots will be black (black oxide coating) and pretty much inert to rusting, Dry it out and you're good to go, alternatively if the tank is out, and you can roll it, you can use something like Red Kote as a tank liner, I used a quart in a 40 gallon tank by thinning it 50% with acetone so it'd flow, in native form its like thick honey and wasn't going to cover everything. 48 hour dry time in a warm environment. don't rush it with compressed air for at least 12 hours.
muriatic acid will clean up the inside right quick, but unless you seal the inside of the tank the rust will just come back...
Is this your mini excavator fuel tank? Can I assume this won't be used full time? and can the tank come off fairly easily? I'd consider taking it off, strapping to a concrete mixer, adding broken glass or gravel etc. rinsing till clean. Then epoxy the inside so it doesn't rust again, and the metal doesn't react with water to start a diesel bug cocktail. Either that, or plug off the rusty tank, and fill it up with used motor oil. Then run the excavator off a 5 gallon plastic boat tank. That works well for me for stuff that sits more than it's used, you take the clean tank to the engine rather than try to keep a bunch of diesel fresh. A pump up sprayer tank works if you don't even need 5 gallons.
I like the concrete mixer idea. I've done electrolytic cleaning (baking soda - battery charger), phosphoric acid, rocks and shaking, etc...they all work. I do have muriatic acid, but haven't tried that yet (saw a youtube vid and happened to stumble upon some acid in a hardware store - cheap stuff). If using water, rocks/jar of nuts etc., make sure you get some diesel in there as soon as your done to avoid flash rusting. A little transmission oil/paint thinner works too...anything oily to seal the fresh metal.
One minor issue with using hycrochloric acid is that it leaves a fair pile of hydrogen ions behind in the metal and they'll start the rusting process immediately. Its rusted about the same time as its dry and the process starts all over, the battery charger method passivates the rust, phosphoric acid will leave iron phosphate behind so its more of a converter than remover. If the tank is super nasty, go with pizzacutting a big hole, wire wheel it all out, covert it, weld it up and coat it. A mig gun and magnets will space the cut out piece just right.
Once you get it clean most motorcycle shops will have a two part epoxy sealer, it may take several kits as your tank will be bigger. Also if you know an aircraft mechanic they have access to pricey but excellent fuel tank sealers.
Cdm, ask your A&P friend if they use 'Red Kote' or something else, I've seen it on motorcycle tanks and I think it mentions aircraft use. I will find out later how well it works
I am not familiar with it but most of the aircraft stuff used to be zinc chromate based and very effective.
Hello, is rust (well guess aluminum oxide ?) as must of a problem in aluminium tanks? Having a transfer tank made of aluminum, but it will be for mini ex so low use. If so any suggestions to coat seal for a Aluminium ? Thxs
well, red-kote would seal it, when I've welded aluminum tanks, make sure they add a few baffles to stiffen the long dimensions to help eliminate cracking, I used to dribble a little loctite green over my welds just in case there was any porosity but never had any leaks with or without it. Make sure you add a small sump just to catch any water before its a problem. I made a small one by cutting a X in the bottom of the tank, bow that section downwards and weld it up, put a 1/4 tank bung on the center point, makes a good low point catch.
Rust in aluminum isn't as big a problem.. BUT as Fast said.. you need to have a way to drain the water out.. Cuz water is in EVERYTHING.. especially fuel.. weather its introduced when filling the tank, a loose fuel cap or condensation.. its gonna get in there. The worse case I've ever seen was in a plastic fuel tank.. go figure.. [water not rust]
I installed a tee into the bottom of the tank where the fuel line comes off. I take fuel from the side port on the tee. I put a street L and a 3 inch nipple with a petcock on the end off the bottom of the tee. Makes it a very simple matter to occassionally bleed any water off. Makes a huge difference in fuel line freeze up matters in the winter also. The street L will let the drip leg stay close to the tank to make it harder to damage. It amazing how much water gets generated from the condensation caused by the warm fuel returning to the tank when it is cool out. I bleed at the end of every day before it has a chance to freeze. I have used Redcote liner also with great success.
Just a word of caution if using tank sealer, it is extremely flammable (explosive) until it is completely dry. Don't do any welding ect. until you know it is dry and don't ask how I know this.
Curious if folks keep their tanks full whenever possible? That is the number 1 way I'd think to stop rust and water in first place. No air, no condensation, no water, no rust. From my flying days, it was imperative we top off tanks for the night. I also thought most, if not all, excavators had fuel filters with a valve on bottom to drain water if machine sat for a while. Personally, I let my machine chew on water...lol...it seems to clear out in a few seconds.
I try to always keep them full. Fuel always seems to get more expensive anyway. Still get a half a thimble of water in the 4-53 Detroits tank after running all day though. Letting it burn off here would mean froze up fuel line many times of the year.
If you go to www.eastwood.com and search "Fuel Tank Repair" you'll see several kits specifically made to do what you're looking for. They are a company dedicated to auto restoration products.
Yeah, thanks for reminder ...I now live in an area that sees light frosting for a few weeks in winter, not the arctic temps you guys see for months...lol. Although, I did suffer for 8 yrs in Sask as a kid (I didn't have to try firing up diesel machinery). I could see the fuel system getting cranky in arctic temps... I recall we used a fogger to get machines going. Not sure what the propellant was...prob similar to Bradex. Not sure that would help with a frozen injection system though.