Any rust in gas tank acceptable?

I have some rust spots in my gas tank and I was wondering at what point I should be concerned enough to take off the tank and do electrolysis on it? Any thoughts?

 

Any rust is a killer on your carbs and valves. It will wear your valves and eventually clog the carb jets.

Be carful with electrolysis. You can inadvertently remove the rust causing the tank to leak. If you have rust in the tank at all, then you also have it in the weld seams of the tank. The seams are notorious for rusting and leaking.

There is no real way of finding out how much the seams are rusted, it's a crap shoot. You roll the dice, do electrolysis, and hope they are not rusted through and start leaking. Or you can clean the rust out with muratic acid that also etches the metal, preventing future rust build up, then use a good tank sealer. And if the seams are rusty, it wont matter for the time being.

You also need to consider how much rust you have in the float bowls of the carbs? If you do not remove the carbs and flush them out really good, you are also asking for trouble.

 

if you have an in-line filter it will catch the rust & if you crack it open (the cheapo plastic ones) it will give a indication as to how rusty your tank is, also pull the petcock & check that filter.

 

when you use muratic acid do you use full strength or do you dilute it? also how long do you leave in the tank? thanks grm

 

It took three weeks of electrolysis in my 5 gal. 650 turbo tank. Also took some metal epoxy to seal up the area's that have rusted through. I have several thousand miles on the tank now. I would have to clean out the fuel filter every tank full or so to get the rust out of it. Luckily I already had a fuel filter that you just unscrew and blow out the filter.
Would I suggest electrolysis again?? took too much time and still did not get the tank clean enough. It left it black. Would have tried the acid wash but never bought the acid. Might do that after summer is over though.

Sean

 

how did you finish off the electrolysis?? You have to rinse the hell out of it after words. I am finishing up mine now - about a week or so. If you swish around some CLR afterwords , flush that, and then swish some rubbing alcohol and let it all dry - it cleans up real nice, for cheap ;-)

then make sure you line the inside of it. I just bought a full tank sealer kit from HIRSCH auto - inside wash, etcher, and sealer for 27.99$ - rated one of the best by the auto restorers - and they got a lot more money invested in their rides then i do ;-)

 

First. There is no in-line motorcycle filter on the market that will filter out rust. Rust will disolve in gas and the particles get about 5 micros in size. Unfortunately the best filter only screens particles latger then 15 microns, so the fine particle rust goes right into the carbs.

Second. After electrolysis you have to completely seal the entire tank. All surfaces, seams, everything. If you don't, the chemicals used in the electroysis process will reactto the hydrocarbons in the gas and severly oxidize the metal on the tank, then you are back where you started, with a contaminated fuel tank.

I've done both methods and many tanks and have found benefits with both. Each way is a messy. ANd you have to properly dispose of the chemicals when is all done. And by all means, Do Not dump any of it down a drain or storm drain to get rid of it.

Muratic acid is used in swimming pools averywhere and is less harmful to the environment then the sodium-phosphate used for electroysis, once you apply the current to the solution, the sodium-phosphate starts a slow acting chemical reaction that you can not stop and phosphates has been banned by the EPA in every state. You will have to put an anode in your tank to prevent it from slowly disolving if you can not 100% get all the chemicals of of the tank and seal everything, and I mean everything. And It is just a matter of time that they ban the laundry soda used for this, and use will have to have a permitt for handling and disposal.

Off the shelf rubbing alcohol is 30% water. Even medical grage now containes water. About 7%, You might as well put a garden hose in your tank and turn on the water. Use Laquer thinner, or Acetone, MEK works the best but its not available in some states.

These are the reasons why fuel tank restoration has moved out of the garage and into a business.

I suggest you use muratic acid at a 50/50 mix. At lower concentrations to start. Use eye protection and very heavy duty rubber gloves. Have a pail of clean water near by incase you get some on your skin, it will burn. But at 50% concentration it is easier to handle.

Be careful with electroysis, I've seen alot of tanks done wrong and wind up leaking or arcing out. 12 vdc at 1.5 A will arc out on the metal surface if done wrong and burn a hole through your tank and you wont even know it because it happens at a slow rate, I've seen 4 tanks this season ruined from this done wrong. Then you finding a new tank.

Just want you to know all the options before you start. Good luck

 

when you use washing soda - it is phosphate free, even after the process (based on all the things I have found)......?

 

Considering the trouble does anyone know how much shops typically charge for cleaning out a tank?

 

It all has phosphates. Hense the name. Sodium-phosphate.

It is a messy process either way you choose to do it. A shop at least is on the hook if something goes wrong and you don'e have to worry about the clean up.

They can change anywhere from $200 - $400 depending how far gone your tank is. There are two out fits that I know that can completely restore a tank. Do a Google search on Tank Restoration and Rust Removal. One plave is in Pennsylvania the other in California. Depending on where you live either one is a good choice.

The guys in Cal. can remove the rust and preserve the metal, but it's a little pricy. A little over $400. They offer a do-it-your-self kit to do this at home, but once you buy the other supplies you need like a very large plastic tub that will hold about 10 gallons of liquid and the chemicals, you are still out about $400. It's just better tho ship your tank off to have it done.

The guys in Penn. with open your tank up at the weld seam and restore it from the inside/out then seal it and re-weld the tank. It cost about $375.

Either way you go, you will have to repair any dents and scratches your self and still have to get the tank painted. My ordeal cost me about $600 when it was all done. And I did most of the work myself.

My advise is, unless you plan on keeping the bike for a very long time, then consider it an investment to prolong the bikes life. Life support if you will. Not any different then restoring and old Mustang or Camero that has the same issue.

 

I assume this is all done in order to hold on to a stock gas tank? As opposed to purchasing a new tank for less than the restoration? (New person question) - Do they not make new tanks for these bikes anymore??? I guess I am just curious for the reason for spending that much on restoration.

 

Are we talking big honkin' spots of rust here or just the light surface 'flash' rust. I have the 'flash' type in both my 80's tanks and haven't really needed to do anything about it. Both bikes run strong with no sign of rust in the carb bowls whatsoever. I do run the stone type inline filters thought. I guess my point is that one needs to evaluate the severity of the problem before rushing head long into a complete Kreme job.

Just my 2 cents.

 

If you use Kreme at all, you are wasting your time and money. I've had tanks fail with Kreme. The 2 part epoxy sealers work the best. The stuff Harley Davidson uses is about as good as it gets.

Any rust is bad. Have you had the bowls off or are you asuming since you have a filter ,it's doing it's job? Once the rust dislodges from the metal it will disolve in the gas and go in the carbs. It's just a matter of when.

Just about everone with and older bike or car is suffering from this same issue. You would be surprised how often the tank gets overlooked. Then when you least want it to happen, your engine will stall out because of the rust. It's just wasier to take care of it when it is a monor issue, and also less expensive.

 

not a hint of the word phosphate in any literature I have seen regarding washing soda (Sodium Carbonate)..... Not to beat a dead horse - but I don't see it..



Wikipedia - Sodium Carbonate

Health Listing - no reference to environmental issues

Another Health bulletin

Another Chemical Report

bascially what I am reading is dont' inhale it, but its fine in small amounts (which we are only using less then a cup of it at a time...

I agree its messy as hell - but its phosphate free from all chemical reports I have found, and pretty benign on the environment (in the diluted form we are using it)........ Now if you use it with stainless steel - you have the issue of releasing chromium which is a whole other story. But for base metals (with the exception of aluminum cause its eats it), it works fine. Its cheap too - picked up a box of washing soda for 2 bucks, cleaned out 2 gas tanks and a mess load of parts with less then 10$ of rebar and buckets I already had.. even if you figure in the 20$ for the CLR to clean up and the 30$ for the sealer kit - its a helleva cheap alternative. And yes arcing does happen, but with a little patience and knowledge you can avoid such things. And if eating away the rust springs a leak on its own - then it was bound to leak sooner rather then later and I would rather have it do it in my garage so i can fix it, then when its full of gas and I am ont the road.

I agree with you completely, if you have the money - pay to get it done right. It saves a lot of time and aggravation, plus it IS done a lot better then we can do it.. However - for less then 50$ i did 2 tanks and a lot of parts, with no mishaps and everything came out beautiful. I even called my local poison hotline and they said it wasn't a danger for disposal as its just a wash detergent - its no more 'harmful' to the environment or you in the diluted state we are using it then you washing your car, as long as you don't drink it etc..etc.. 'standard safety precautions etc..' (their words, not mine).

josh

 

ya I heard bad things about kreem. I just used Hirsch Auto tank sealer - its a full kit, a wash, etcher and sealer - worked absolutely great and was even cheaper then the kreem junk ;-)

 

You might want to check your chemistry, I do not think gasoline is a good rust solvent. If that were the case, wouldn't there be NO signs of rust in the tank? I've had the bowls off many times, and no sign of rust in the bowls even with visible 'flash' rust in the tank. I also have a 1966 Ford F-100 that the filter clogged on due to rust. I'm just not buying the whole 'gas dissolves rust' theory.

 

if your really worried about using washing soda, use baking soda, they put it in toothpaste
gas does not dissolve rust

 

Baking soda doens't work, and washing soda IS Sodium Carbonate...

Muriatic Acid is Hydrochloric Acid, and will flash rust VERY quickly...
Phosphoric acid will leave a coating of zinc oxide... any acid will dissolve metal so use with caution.

 

I tried CLR. It will work on minor surface rust, but you still have to etch the tank when your done or the rust will return.

The washing soda works, but the amount you need to do a typical 5 gal tank is about 5 cups. in a submersed tank, about 2 cups going directily in the tank.

You are right, you could dump it down the drain, but be careful it is a reactent if it contacts other things typically found in storm drains, like oils and such.

 

wow! i've used less then 1 cup 'in' my gas tank each time (i flushed it every other day - for 6 days), rinsed it out each time, at the ed of which i used the CLR (for the remaining surface rust) and then used a etcher/sealer... You do have to do something immediately after the clr or it will flash rust, within 10-20 minutes (found that out on some smaller pieces).

for standard electrolysis (based on all sites i found, so this isn't my information) is about 1 cup for a 5 gallon bucket - more doesn't help and less just means it will take longer......

 

maybe all baking soda doesn't work but mine does, using it on pair of wire cutters now
PH-up for swimming pools = sodium carbonate and comes in big containers if you feel the need to use a mass quantity of it

 

Hello,
I did the electrolysis thing on my 750 tank. I took it slow ~ 10 days or so got my chemical @ a pool place. Mixed it a little heavy 2 cups to 5 gallons of water. It came out great! Got a sealer off of the internet something used to seal airplane fuel tanks. Suppossed to be 1 of the best. Real happy with the results!
George

 

i have two pint containers of kreem, i keep readying that people has problems with it. i am not sure if i should use it or try por-15. can someone that has used kreem please give me some advice on how to use it or not to use it. thanks grm

 

Some folks love it, some hate it, kind of like 'what oil do you use'. I've 'Kreemed' a tank before, messy, but it DOES work!! If you already have it, I'd say use it.

 

Swampfox; No they don't make gas tanks for most of these 22-28 year old bikes anymore. The lucky ones among us got our hands on a bike that was well kept enough to prevent the tank from rusting. A lot of these bikes get picked up for so cheap because they've been sitting somewhere, and if they had an empty or nearly empty tank when parked, then...most "boneyard" tanks you find have likewise sat and rusted.

 

I just finished cleaning my XJ550J's tank and 100% agree with what you said. I started out with electrolysis, but the rust returned fairly quickly after taking it out. I then tried muriatic acid. The inside of the tank was shiny and beautiful, but within _minutes_ new rust formed, before I had a chance to remove the water or dry it out. Finally, I went with phosphoric acid- concrete cleaner/etcher purchased from Lowes for about $8.00. I used about a quart, filling the rest of the tank with water. After about an hour soak I drained as much of the acid as quickly as I could. Then I filled the tank with gas and Seafoam to hopefully take care of the small amount of remaining acid/water mix. The result is a 100% rust-free tank with a nice zinc coating on the inside.

 

I'm going to go this route cleaning my tank, question though - Do I need to throw in something abrasive (extra nuts, BBs, etc) to loosen up anything? Any specific sealer to use with this?

 

I was gonna try aquarium gravel and kerosene in the tank I just got, not obviously rusty, was stored oiled by salvage yard. Interesting side note: In the online microfiche for the '81 550 Seca are "tech bulletins" and one of them pertains to rusted fuel tanks RIGHT OFF THE BOAT and what the dealer should do about it before delivering the bike to a customer. Apparently rusty gas tanks are "hereditary" to XJ's...

 

In my experience lots of old bikes end up with rust holes in the tank from the small amount of water content petrol has, as water is heavier than petrol it sinks to the bottom and usually ends up in the bottom rear corners of the tank where it happily rusts it's way out.

For minor internal surface rust I've put a couple of cups full of sand in an empty tank and gaffer taped it to the outside of a small concrete cement mixer and left it for an hour 8O A little bodgy but gets it nice and clean inside, just make sure you throughly wash the sand out and fit an inline fuel filter. Fitting a fuel filter should be a matter of course for an old bike really for keeping rusty crud out of the carbs, the clear plastic types are good as you can, at a glance, see if petrol is flowing.

 

If you are going the phosphoric acid (concrete cleaner) route, you do not need any kind of abrasive. The acid will take care of the rust on its own. I left the acid in the tank for about 2 hours, but YMMV. After that, I drained the acid and the tank looked good. When I drain the tank there is always 1-2 tablespoons of liquid left, so I put some Seafoam in the tank to "dry" the water in the acid, and filled it up with gas. It's been 5-6 weeks now, and the rust has not returned, so I'd classify that as a success.

 

I have used the POR-15 and LOVE IT!!! It's great stuff. They sell it in a kit that removes some of the rust, etches the tank so the epoxy stuff sticks, and then the epoxy it's self. I used duct tape to cover the petcock holes. Make sure you follow the directions!!!! No shortcuts or you'll hate yourself. Very reasonable too at about $45 for the whole kit. The best part is, if you have the really scaley rust off this suff will stick to the metal, the rust, and anything else you put it on. Speaking of, if you want to keep the paint job you have protect it well. Good luck!!!

 

My question is:


What is seafoam and where is it found?

I have never run across this product.

 

Seafoam

 

well thank you, TheHound, seems it's been under my nose my whole life, just never noticed it, thank you

 

IN part UKSteve said,

Question: when in the prime postion i see fuel flowing. However in the Res or ON postion filter doesn't look as though it has fuel in it at all while running or, off for that matter. Doesn't this indicate a fuel flow problem.

As I am addressing rust in the tank may as well solve all the problems now.

The bike sat 9 years with full tank of gas.

Thanks

 

I have these materials just wondering what to block the petcock and fuel gauge hole with while doing the acid wash?

Thanks

 

Well if you have fuel in prime, the line is clear, but not in on or res, it's probably a vacuum issue with the petcock.
Either the diaphram has a hole or there is a leak on the way there.
But if the bike runs you must have fuel in the on position or is that the problem?

 

Well i did quick clean on carbs and it did start and run but ran differently everytime i started it, so took carbs back off went all the way thru them so I haven't had it started yet to see where I'm at with it. Dealing with rust in the tank before i restart bike.

I started it a total of 5 or 6 times and come to think of it the last 2 times it didn't want to run kept dieing which is when i noticed fuel filter seemed odd. The vacum line was replaced new

 

I scrounged around and found a piece of plastic just larger than the petcock's mounting surface and drilled 2 holes in it to match the mounting pattern. Then I put some Permatex gasket compound on both surfaces and assembled it. It didn't leak a drop during the cleaning process.

- Mike

 

I'm a fan of the coatings. But, as someone said, you really really must follow every detail of the directions. A bad job on it will make you want to kill yourself.

 

for the guys that are using CLR or other rust removers,,,,try adding some oil to the mix as it will stop the flash rust,,,,,did on my CLR mix,,,,Dan