Author Topic: Cleaning a fuel tank... (Read 4060 times)

sbparks · « **on:** July 31, 2010, 08:35:06 PM »

Folks,

I've run in to a little trouble with my bike... CB750K4.

Seems that my fuel tank has quite a bit of sediment in it. I think its sand... Not sure. Might be sand from a sandblaster. I'm trying to figure that out.

Any suggestions for removing the sediment?

I've made the stupid mistake of trying to run the bike with the junk in the tank. Well guess what, now I am cleaning the carbs again! After a complete rebuild eariler this year. Oh well!

Thanks for the suggestions.

Scott

ev0lve · « **Reply #1 on:** July 31, 2010, 08:45:45 PM »

It's not sand

Rinse it all out with water and some drywall nails or use one of the derusting procedures - The Works toilet bowl cleaner is pretty good and cheap. Be prepared for a leaky/pinholed tank once you get that done though - turned out mine was mostly held together by rust

http://forums.sohc4.net/index.php?topic=31970.0

sbparks · « **Reply #2 on:** July 31, 2010, 08:51:07 PM »

I wish I could get a picture of the innards of the tank.

Looks pretty darn clean, although I think its been coated - Not sure (I'm trying to find out). The tank looks like a grey coat of primer paint. Some texture to it.

I don't see rust, however, I can't see all the surfaces in there.

The sediment is grainy. Not flakey. It is black/brown.

Scott

ev0lve · « **Reply #3 on:** July 31, 2010, 08:58:53 PM »

Hmmm, I'm wrong then. A previous liner job shouldn't be coming off like that I wouldn't think.

Wait a bit for those in the tank lining know to stop by. Sorry I couldn't be more help.

ekpent · « **Reply #4 on:** July 31, 2010, 09:58:59 PM »

If you think the tank is coated and you do not see any rust you can still remove the petcock and get in there with water and maybe a few drops of dish soap and really agitate and flush out your gunk or sediment. A little degreaser will also break the gas bond.The main issue is to get the flush out quickly,I have a shop vac that can be reversed to a blower that I insert into the top of a tank for a quick dry---------

dave500 · « **Reply #5 on:** August 01, 2010, 01:08:46 AM »

is it summer where you are?hot water with dish soap or degreaser twice,slosh it around like crazy,dry it right out with a vacuum cleaner hose stuck in the filler hole,do it with the hose both ways for a while,if you have an air compressor blow it for a long while aswell ,then rinse it out again with metho or what ever you call it stateside twice,then rinse and dry it again with some gasoline and dump it on your weeds.do all this with the tap removed.

sbparks · « **Reply #6 on:** August 01, 2010, 04:00:06 AM »

So, it sounds like I need to hit the tank with some water and dish detergent.

The liquid (the water) with the detergent should release the rust/sediment that's adhering to the walls? Right?

I't a bit of a pain to get everything through the petcock hole at the bottom and the filler hole has a 'neck' inside that prevents everything from spilling out of the tank (if I held it upside down). I guess that's why I just need to 'rinse and repeat' until I get it right.

Dave500... I liked your comment about what to do with the leftover gasoline... hit the weeds with it... That's what my dad taught me to do way back when. Contaminated gas, what *do* you do with it? I can let it evaporate OR I can do something useful... kill them damn weeds! Love it.

Question - If I were to recoat the tank, what precautions do I need to protect the pain (the finish) of the tank? Can I wrap in plastic bags?

I'll keep working my tank guys (while I completely clean my carb parts again!).

Scott

Alan F. · « **Reply #7 on:** August 01, 2010, 05:44:17 AM »

Here's a small trick to try first, just to find out if it's actually powdered rust in your tank. Get a magnet that you can tie a string around and drop the tethered magnet down into your tank. If the powder sticks to the magnet it's rust and you can get the large majority of it out this way before flushing the tank.

Something like these are ideal: http://www.radioshack.com/product/index.jsp?productId=2102641

You may want to cover the magnet with a piece of plastec wrap or something to make cleaning it off easier...just unwrap to clean...

I read all this in another thread a while back, forgot just whose idea it is but it's not mine.

sbparks · « **Reply #8 on:** August 01, 2010, 08:15:04 AM »

Wow - Great idea. Now why didn't I think of that! Thanks.

Alan F. · « **Reply #9 on:** August 01, 2010, 08:11:42 PM »

Thats what i said when I read that trick too. It aslo works to get the nuts & bolts or screws or whatever you use to loosen rust with back out of your tank too.

Popwood · « **Reply #10 on:** August 02, 2010, 10:49:31 AM »

I did a tank this past winter. First did the nuts and bolts routine but after my arms got too tired regrouped and used the electrolysis method. I was very pleased with the outcome. My son used it as well on a couple tanks with good success, as well.

sbparks · « **Reply #11 on:** August 02, 2010, 06:22:10 PM »

I used water and detergent to clean the tank. Then rised several times with plain cold water.

The tank dried in the sun and then again with a small light bulb under it (a heat source).

No more particle in the tank, but I do have a light sheen of oxidation (rust) inside the tank now that the interior came into contact with water. I'm guessing that the tank *is not* lined or coated inside.

So... Time to coat the tank? Or is it OK to run a tank with some light rust inside?

Scott

Alan F. · « **Reply #12 on:** August 02, 2010, 07:29:31 PM »

it should be ok to run, but keep it in the back of your mind that you'll have to take care of it sooner or later. There are several methods that work well and are easy. I'll be using 'the works' toilet cleaner and rinsing with a baking soda and water solution to neutralize the acid, I've read good things about this process in regards to 'flash rust' which can quickly form if straight water is used to rinse the interior. I'll be giving mine a final rinse with 'dry gas' to collect any remaining water and coat the inside of the tank. (that stuff is pretty oily)

Alan

beatnikchicken · « **Reply #13 on:** August 13, 2010, 07:24:01 PM »

you can also swirl acetone around in the tank to speed up the drying process! I used 'The Works' method recently, and it was a-mazing! I just forgot to remove the fuel filter that sticks up into the tank and... well, it melted... but other than that... fantastic!

sbparks · « **Reply #14 on:** August 13, 2010, 08:57:48 PM »

Folks,

I've been working way too hard on this problem and I'm still not happy with the results. My tank still shows sediment (rust) inside.

I've used compressed air, washed with detergent and rinsed with water. I thought things were nice and clean so I figured I'd go ahead and coat the tank with Kreem.

Ordered the large size Kreem kit and I used the Prep A bottle in the tank. This is supposed to remove rust and etch the tank. I left this solution in for 48 hours.

My goal tonight was to rinse the Prep A out (with water) and then use the second step, Prep B. Prep B is MEK and that is supposed to remove the water from the tank.

After Prep B, I am still getting loose sediment. I am pretty frustrated at this point. I don't think I want to attempt to apply the coating (the Kreem) because I am afraid the tank isn't completely clean.

I need to rest now and step back from my project, but I am thinking that I should attempt a 'The Works' treatment to my tank. No point in trying to coat with Kreem if the tank isn't clean.

I would be satisfied if I could just rid the tank from this loose rust!

Any thoughts before I proceed?

Thanks

sbparks · « **Reply #15 on:** August 14, 2010, 03:39:45 AM »

Now that I've slept, I am thinking that the top of the tank (the part I can't see), must still be rusty and be the source of the rust sediment.

I'll attempt 'The Works' proceedure on the tank. Paying attention to get the solution up to the top of the tank. I'll use it full strength.

Rust does form up at the top, right? If the tank is left with a partial amount of gas, the water vapor in the air can rust the tank at the top.

Frustrating part is the portion of the tank that I can see looks *really* good. Nice consistent grey finish. That's why I originally wondered if the tank was already coated.

It won't be today, but I'll keep working at it!

Scott

faux fiddy · « **Reply #16 on:** August 14, 2010, 03:46:19 AM »

There's always a way to use electrolysis, filling the tank, and hooking a battery charger up to the tank, and I believe you put the anode into the water.

There might be an electrolyte added to the water that helps to expediate the process,though I'm not real sure about that. Lots of people here and other websites have writen on using this to separate rust.

beatnikchicken · « **Reply #17 on:** August 14, 2010, 02:02:22 PM »

Also, instead of nuts and bolts I would definitely recommend buying a bike chain to use instead. Sure it might be $7, but it if saves you a couple of hours or days trying to get all of those little things out of your tank, I feel it's worth it. Though I suppose you could get those out with a magnet.... either way, it worked well for me!

ev0lve · « **Reply #18 on:** August 14, 2010, 03:45:01 PM »

Quote from: sbparks on August 14, 2010, 03:39:45 AM

Now that I've slept, I am thinking that the top of the tank (the part I can't see), must still be rusty and be the source of the rust sediment.

Rust does form up at the top, right? If the tank is left with a partial amount of gas, the water vapor in the air can rust the tank at the top.

Stick a mirror in there if you want to know for sure. I would think not but I'm no expert. Learning about it with my tank, water is heavier than gas so, counter-intuitively, it rusts out the bottom of the tank first.

Quote

I'll attempt 'The Works' proceedure on the tank. Paying attention to get the solution up to the top of the tank. I'll use it full strength.

Probably less important to get it filled to the top than it is to drop some nails or a chain in there and agitate the mix consistently. I did mine for an hour full strength with drywall nails and found a lot of the bottom of my tank was made out of rust and started leaking but boy was it nice and clean

Here's everything I could find on Kreem
http://forums.sohc4.net/index.php?topic=38242.msg650129#msg650129

And here's what happened when I did it
http://forums.sohc4.net/index.php?topic=38242.msg653097#msg653097

Almost a year in service at this point. One way or another take your time, follow the instructions to a T and give it plenty of time to cure once you Kreem it.

Hope that helps and good luck!

sbparks · « **Reply #19 on:** August 15, 2010, 06:30:27 PM »

Back after an exciting weekend.

I was able to attempt 'The Works' treatment on my tank... added the cleaner to my tank - Full strength, One bottle.

The surface rust started disapperaing immediately. I let the solution (started as a nice, clean light blue) sit in the tank for just short of an hour (when I was done the solution was a yellow/green).

Everything looked great except for some rust-like substance down at the lower seams (where the bottom surface is mated to the vertical top surface). I shook the tank to apply over the entire surface of the tank.

After rinsing the cleaner out with water, I immediately added two tablespoons of baking soda to the tank with more water. I could hear a 'reaction' inside the tank (hissing?). The baking soda really did prevent the immediate flash rust that I experinced the first time.

I added acetone this time to evaporate the water from the tank. The acetone came out light brown and immedately started the flas rust process to begin. I continued to dry my tank with a hair dryer this time.

Does anyone know why adding a dryer (MEK or Acetone) will cause the flash rust to occur? I've got that light rust coating, but hopefully, no more sediment. I'll know for sure when I add some gasoline and shake it about.

Is it OK to proceed with the light coat of flash rust or should I 'Works' it again with a method to prevent the flash rust?

I'll try to take some pics, but that will be tough to get those from inside the tank.

Thanks, Scott

ev0lve · « **Reply #20 on:** August 15, 2010, 07:44:01 PM »

Quote from: sbparks on August 15, 2010, 06:30:27 PM

Back after an exciting weekend.

I was able to attempt 'The Works' treatment on my tank... added the cleaner to my tank - Full strength, One bottle.

The surface rust started disapperaing immediately. I let the solution (started as a nice, clean light blue) sit in the tank for just short of an hour (when I was done the solution was a yellow/green).

Everything looked great except for some rust-like substance down at the lower seams (where the bottom surface is mated to the vertical top surface). I shook the tank to apply over the entire surface of the tank.

After rinsing the cleaner out with water, I immediately added two tablespoons of baking soda to the tank with more water. I could hear a 'reaction' inside the tank (hissing?). The baking soda really did prevent the immediate flash rust that I experinced the first time.

I added acetone this time to evaporate the water from the tank. The acetone came out light brown and immedately started the flas rust process to begin. I continued to dry my tank with a hair dryer this time.

Does anyone know why adding a dryer (MEK or Acetone) will cause the flash rust to occur? I've got that light rust coating, but hopefully, no more sediment. I'll know for sure when I add some gasoline and shake it about.

Is it OK to proceed with the light coat of flash rust or should I 'Works' it again with a method to prevent the flash rust?

I'll try to take some pics, but that will be tough to get those from inside the tank.

Thanks, Scott

If you're going to Kreem it you want to rinse it with the MEK/Acetone drain it and then IMMEDIATELY start in on the Kreem. Like, don't bother to get it dry, just get most of it out and dump in the coating.

seaweb11 · « **Reply #21 on:** August 15, 2010, 10:28:35 PM »

After the last rinse I add a bit of Diesel fuel to stop the flash.

dave500 · « **Reply #22 on:** August 16, 2010, 02:43:20 AM »

ive used the por tank sealer and it comes with a "metal ready" product that leaves a zinc coating,it worked great,on the tank im doing now i used the australian made kbs brand equivalent and it came with a litre of 'metal prep" that worked fantastic,both have a silver grey thick paint finish that hardens like glossy glass,,the prep must be spot on though,i dried mine for a day in the sun and also had a vacuum hose in the opening for half an hour,our humidity here is low now at 35%.

shizzomynizzo · « **Reply #23 on:** August 16, 2010, 03:00:05 AM »

Quote from: dave500 on August 16, 2010, 02:43:20 AM

ive used the por tank sealer and it comes with a "metal ready" product that leaves a zinc coating,it worked great,on the tank im doing now i used the australian made kbs brand equivalent and it came with a litre of 'metal prep" that worked fantastic,both have a silver grey thick paint finish that hardens like glossy glass,,the prep must be spot on though,i dried mine for a day in the sun and also had a vacuum hose in the opening for half an hour,our humidity here is low now at 35%.

I have used the por 15 as well. The zinc coating is from phosphoric acid. It looks like flash rust to some people, but is not. I would recommend getting some phosphoric acid before using the kreme. My tank had sediment in it too before the PO did the kreme coating, and it was a real pain to get out! The lining and the rest of the sediment. Ended up getting a new tank.

You don't have to get the whole por15 kit to get the metal ready. PPG and other paint companies make a "metal ready" type of prep. Sherwin williams automotive paint stores, and many classic car parts stores (like National Parts Depot) carry these products for 10 bucks a bottle and regularly stock it.

I don't think a little surface rust will hurt anything, but make sure the tank is completely dry prior to coating it.

Good luck!

sbparks · « **Reply #24 on:** August 16, 2010, 05:52:45 AM »

At this point, I am tempted to give the tank a quick rinse with another shot of 'The Works' again to clean up the surface rust.

The baking Soda solution was great for holding the flash rust at bay. Seemed like the tank was clear for at least 10 minutes before I rinsed with the acetone. It seems like the acetone immediately starts the oxidation process. Even the acetone that I poured out of the tank was brownish/red with rust.

I'll try skipping the acetone step and rinsing with diesel. If the tank looks good after the diesel rinse, I'm going to give it a go and try to use it and attempt the coating (the Kreem or POR) over the winter when I have a little more time to let the coating cure.

Thanks for the encouragement!

Scott

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Author Topic: Cleaning a fuel tank... (Read 4060 times)