The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on November 12, 2010, 07:03:06 PM
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Bad news.
I flushed my gas tank with water a few weeks ago (got all the water out and dried it) and then proceeded to prepare to paint the tank and other parts. During that process I was doing a lot of wet sanding. I had plugged the tank to prevent water from getting in but damp vapor got in anyway. I noticed at one point that the inside of the tank was damp so I dried it out. Well now that the painting is completed (looks great by the way) I decided to stick a flashlight in the tank to see if any rust had formed and yes it has. There are little rusty lesions in the tank. So I'm guessing that the coating was marginal.
I know there was a posting recently on flushing the tank and re-coating and went looking but could not find it. So here are the questions:
1. What product is recommended to clean the tank and remove all the factory coating. Is the procedure included in the product packaging?
2. What product is recommended to re-coat the tank? Same question re the procedure?
3. What is used to seal the tank before the products are poured in? I'm assuming that the petcock is left out.
4. Are there any hidden vent holes that I need to protect so that the tank will operate correctly after re-coating?
5. Are there any other precautions or procedures I should be aware of?
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Vinegar to remove the original red lining.
I think I would go with POR-15 for a relining product.
It would appear they have more than one kit, and I am not sure which to recommend, as I've never done this.
http://www.por15.com/Fuel-System-Restoration/products/12/
Since I've never done it, I am not much help on the rest. But there are plenty of folks here that can.
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Thanks Rob. Do you know if the vinegar will get rid of the rust also?
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I doubt it. But the etcher in one of the kits would probably do it.
http://www.por15.com/PREP-READY/productinfo/MRG/
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Thanks Rob. The etching looks good. Now the question is how much? Maybe someone who has done this will chime in.
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Well, they sell the coating in pints and quarts. I'd be willing to bet (not too much!) that a pint would do it.
I don't know where everyone is, tonight!
http://www.por15.com/POR-15/productinfo/1GB/
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I went through this process about a year ago .
I had a fuel tank from an '84 LS, the interior of the tank looked like an old exhaust system off of a four wheeler .
I got a POR 15 motorcycle kit and tried it .
The first component is a 'sludge' remover, the quart bottle had the contents that looked like it was a sodium hydroxide solution, common drain cleaner .
I tried it and it did some good, but not nearly good enough .
The second bottle had some sort of acid solution, again in my instance, it didn't really do any good .
I had heard of using molasses in water, sounded a bit out there, but I tried it .
To make the story short, molasses in water 'ferments' into a compound that contains acetic acid, the acid that is in vinegar .
I have to admit, it did a great job of removing the rust and remaining liner in the tank .
I have no idea what acid concentration the solution had .
If I were to try it again, I think I would try generic white vinegar and see what happens, with the average acid concentration of 4-5 % in retail vinegar, it may take a bit longer to remove the rust and liner .
A couple of members have used muriatic acid with good results .
You can get 35 % muriatic acid for use as a ph reducer for pool use, I don't know if it is widely available in your area or not .
The sealant in the POR 15 kit comes in an 8 fluid ounce, or 237 ml can, more than enough to do one R65 fuel tank .
When I try this again with the fuel tank from the Guzzi, I'm going to just use vinegar, and get the smallest can of liner material I can get, as the POR 15 motorcycle kit, at least in my case really didn't do the job.
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Thanks Bob. I think I'll try the vinegar. I'm assuming I will have to turn the tank every half hour or so to get the vinegar working in every nook and cranny. Any idea how long I should leave it in the tank?
Right now I'm experimenting with some vinegar in a small bowl and some saran wrap. I'm thinking that if I put the saran wrap over my gas tank stopper it will stop the vinegar from leaking out the vent in the cap (I'm assuming there is a vent in the cap). I'm also thinking of making some kind of a stopper for the pipe leading to the carbs and wrapping that with saran wrap. Any thoughts on that? Also I'm thinking there is no other vent...am I right?
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There is a vent in the cap, I think.
The overflow inlet is located at the top of the tank, part of the cap opening, I believe. See the outlet located on the bottom of the tank? Just follow that up to the top and you should see it.
I just used white vinegar for the first time to clean the lime scale off of my bathroom shower head. Since I have a removable WaterPic, I just took it off and put the whole thing in a 1 gallon plastic zip-lock bag and let it soak for about 8 hours. I found out some have really small holes in them!
I had always assumed one would just pour 5 gallons of vinegar into the tank and let it do it's thing. Hopefully a rubber stopper in the petcock hole would be enough, but it would have to be a GOOD fit.
And then, of course, you have the mess to clean up, afterward. Too bad you painted the tank, first. The best way to go about this is to take it to a radiator repair shop and have them "dip" the tank.
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I used rubber stoppers in all of the holes in the tank, I removed the fuel tap as well .
I completely filled the tank when I did this process .
The tank needs some sort of vent, as during the rust removal process, gasses are released, so don't completely seal the tank .
I'm not certain, but I think vinegar may very well stain the paint if it gets on a freshly painted surface .
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Bob I'm not sure I can find a rubber stopper to fit the gas cap. So my question is because I need a vent why not just leave the gas cap in. Also why not leave the fuel tap in...would it get damaged by the vinegar?
I've thought about the new paint getting damaged and I'm thinking I'll have to be really careful. I'm also thinking of "almost" filling the tank with vinegar on the first go round and then having a second go round with vinegar but inverting the tank this time so that the coating on the inside top of the tank gets cleaned off. I've done a little experiment with saran wrap in a bowl overnight to see if the vinegar would burn through it...it did not. So I'm thinking on the second vinegar treatment to put saran wrap over the the fuel cap to stop the vinegar from leaking through the vent in the cap when the tank is inverted....any thoughts on this method?
I used to use muriatic acid in my boat to clear sewage hoses and I've used it to etch concrete. That is rally nasty stuff. It would certainly do the job but I think I'll stay away from it unless I need it.
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I tried cleaning up a fuel tap using 9% acid content vinegar, there was rust on the threads .
After 30 minutes, I saw the acid was attacking the zinc or whatever plating is on the steel parts .
The aluminum wasn't any happier, it had turned almost black .
I personally wouldn't expose the fuel tap to vinegar .
You need to get the top of the fuel tank clean down to bare metal, or there is the possibility of the lining material you use, may not adhere to the remaining OEM liner .
Large rubber stoppers are available at home brewing and wine supply stores, that's where I got mine, don't know if you have any nearby or not .
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Thanks Bob. I'll try my winery.
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I seem to recall a similar thread a while ago where Coke (or Pepsi) was used to good effect,, better than drinking it anyway.
Lou
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Look at a container of Coke, it contains phosphoric acid .
Lou, thanks for bringing this up, as it is another effective way to clean out a tank .
I forgot to mention phosphoric acid, it will work, but it's around $12US per gallon and it's useless after using it for this .
It's a good etching solution after using some other acid or substance to clean up a fuel tank interior .
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Actually it may have been me that brought up the coke idea some time back. A friend of mine used it to free up his through hull fittings on his boat...left it in for 24 hours and it worked like a charm. But as Bob says, it may not dissolve the painted liner and that's what I have to do first. The coke will work on the rust though...maybe a second stage idea if I don't go with the POR-15 product to get rid of the rust.
At 12:45 pm today I put about 22 litres of 5% acetic acid white vinegar into the tank. I filled it to the brim. We'll see how long it takes to do the job.
I did get the bungs at a wine supply store Bob but they have a hole in the middle to allow it to gas off. The small one I bought for the petcock hole was too big and I couldn't shave it down very easily so I found a cylindrical shaped tool in my tool box that was just a tad smaller than the inside diameter of the outlet. I cut some old inner tubing to fit over the tool and pressed it into the outlet. It's holding now but I'll see if the vinegar does a number on the inner tube over time. I may have to replace it. Maybe I should have put some saran wrap over the inner tube :o
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I had the molasses solution in my fuel tank for around 3 weeks and it didn't do any harm to the rubber stoppers .
I got smaller rubber stoppers to plug the hole in the large rubber stopper that goes in where the fuel cap sits at a home improvement store (Lowes), I believe they were in the packaged hardware section that is usually in steel cabinets with drawers .
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Bob what would be your guess as to how long I will have to wait with the vinegar in the tank? Also would you recommend that I occasionally turn the tank upside down to ensure the top of the tank is getting treatment? It is filled right to the top the two vents in the the fill neck right now.
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I'd guess leave it alone for 10 days, then see what the condition of the interior is .
You're going to need to turn the tank upside down, as there is an area at the top of the tank that is not in contact with the liquid .
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I've used the POR 15 and whilst the results were acceptable it was a real hassle to do.
I've heard great things about removing rust using a solution of sodium carbonate (washing soda) and electrolysis: remove fuel tap and bung the hole, fill the tank with the soda solution then hang an old chisel in the tank making sure it can't touch the tank itself. Hook this sacrificial anode up to the positive of a 12v battery and connect the body of the tank up to the negative terminal. One refinement is to put the battery on charge whilst this is going on. Leave in situ for around three days removing scum from the filler hole and making sure the electrolyte level stays good.
This leaves the tank clean but uncoated. I plan to use this system when I'm next faced with cleaning out an old tank, and I'll probably leave the inside bare and just inspect annually. New paint etc. is as likely to create as many problems as it solves due to the amount of ethyl alcohol in fuel, and resin lining (like the POR 15) only works if perfectly applied.
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The POR 15 and Kreem, the only two products that I've seen available locally, really stress on getting the tank free of crud inside the tank, I know the products don't adhere very well to the OEM liner .
POR stands for 'paint over rust', I've been told by car restorers, that POR 15 is more tolerate of rust in the tank than Kreem .
The prep work for relining the tank is a pain which ever method you choose .
Like any painting project, 80 % of the work is in the preparation .
I'd like to hear how the electrolytic method works out on your fuel tank .
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Daniel that electrolytic systems sound interesting. I think I'll consider it when I do the next step to get rid of the rust. Do you think a marine sacrificial anode would work as well as an old chisel (I don't want to sacrifice a chisel).
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Daniel that electrolytic systems sound interesting. I think I'll consider it when I do the next step to get rid of the rust. Do you think a marine sacrificial anode would work as well as an old chisel (I don't want to sacrifice a chisel).
That's a good question - my understanding is that the sacrificial anode needs to be mild steel in order to react with the iron oxide (rust) in the tank, so any piece of steel rod or bar should suffice. Here's a website showing the process using a coat hanger: http://www.ehow.co.uk/how_6827738_clean-gas-tank-tap-electrolysis.html
My experience of marine anodes is that they are usually made of something like zinc in order to protect expensive aluminium alloy boat components and so probably wouldn't work, however as I've never attempted this technique what do I know!
Like others here I'd be keen to hear how this technique works in practice.
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I don't know if the composition of the anode is critical or not, you could try just a plain old piece of steel or iron as an anode .
Again just thinking here, but you may need a large surface area for the anode to work, or you may need to change a smaller one if it gets covered completely with transferred material from inside the tank .
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From my experiences, a piece of concrete rebar, used as an anode, works well.
Monte
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Rebar sounds good...got lots of that...and it's rusty. :)
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The best solution for rust inside the tank is to use a 10% solution of phosphoric acid. I cleaned out the tank with the following procedure:
1. Empty the fuel
2. Remove tank from bike and remove petcock(s). Plug petcock holes( I use trimmed wine corks)
3. Wash with hot water and detergent (1/2 full and rock the tank back and forth)
4. Add 20 litres of cold water and then 2 litres of Phosphoric acid ( water first, THEN the acid.
5. Allow to stand 24 hrs
6. Empty the tank.
7. Flush with a baking powder solution of 4 tbsp to 10 litres.
8. Spray the inside with WD 40 (dewatering)
9. Flush with thinners.
10 Seal tank with a proprietary sealant, or denture fixative (just joking!)
Ive used this on 2 tanks with very good results!
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Well the tank has been "almost" full of vinegar for almost 2 days now. I just noticed that the liner is starting to detach from the tank. I scraped the inside of the neck, where there is vinegar, with my finger nail and most of the liner in the neck came off. So it's working.
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Good to hear it's working !
What's the temperature of the tank, any id, I'm going to guess it's on the cool/cold side ?
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The tank is sitting in my basement and it's a little cool down there. I'm guessing it's about 67-68F. Would it work faster if it was warmer do you think?
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I was figuring it was a lot cooler than that !
I'd just leave it alone .
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When I lined the tank on the Junkyard Dawg I cleaned it out with Muriatic Acid. Took about 12 hours and it removed every speck of old liner and rust/crud. This was followed by a good water rinse followed by a good flushing with acetone. This was all in accordance with the instructions with Eastwood's lining kit...
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Justin it's hard to know who's product to use. I agree that muriatic acid will do the job, having used it before but with me spilling stuff on the tank as I flip it I wanted to go with something milder so I'm using vinegar right now to remove the liner. I've ordered the POR-15 kit. I checked on Eastwood's kit and read the only review I could find on that product and it was not good...but who's to know whether the person that used it got the tank clean and dry before using it.
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Bob when you used molasses on your tank did the liner come off in flakes before you emptied it? Did you have to shake the tank with the molasses in t to shake the liner loose?
Just now I stuck a screwdriver in the tank and by just touching the liner it came off in large (2") flakes but it hadn't moved by itself. The metal underneath is clean as a whistle. Of course I cant see or reach most of the tank so I don't know what's happening there (I assume it's in the same condition). I'll leave it a few more days before I flip it to treat the liner at the top of the tank. Maybe I'll see some major flaking at that point.
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The molasses mixture was a dark brown color, couldn't see through it .
When I drained it out, the liner came out in clumps along with all the other sludge in there .
The only area that it held onto, was in the seam area, but it eventually came off of there as well .
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You may need to resort to putting in a handful of nuts & bolts to shake around in there.
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JI've ordered the POR-15 kit. I checked on Eastwood's kit and read the only review I could find on that product and it was not good...but who's to know whether the person that used it got the tank clean and dry before using it.
The Eastwood kit was more of a PITA than the POR-15 and actually turned out to cost more. I have used POR-15 on three tanks and just tried the Eastwood kit because it was on sale. After I received the kit the instructions state you have to buy the acid and acetone which more than made up for the price difference.
The POR-15 does not have to have a rust-free surface, it just needs to be clean. Follow the instructions in the POR15 kit and you'll have no problems.
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I'd actually not use nuts and bolts in there - vigorous shaking could cause dents that would show through - but maybe some marbles or aquarium pebbles or something....
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I recall some people I used to know set a gas tank in a cement mixer...padded and protected of course with some marbles or something like that inside...not sure that wouldn't dent the tank though.
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My original red lining is in excellent condition but if it wasn't and when the time does come after going through all the grief to strip the old lining off I think I would be sorely tempted to leave it as bare shiny metal and trust to an annual drain and clean to keep corrosion at bay.
Anybody done that ?
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I have had good luck with BBs. A lot of work, but cheap.
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The inside of my '74 Honda CB200 is silver, but I don't know if it bare metal or some kind of paint. It was well cared for, though!
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Barry, I don't know about the petrol in England, but the gasoline over here now contains ethanol that I read somewhere has a water component to it. I also read that if temperatures vary somewhat the water can separate and sit in your tank. Given that, I would not let the tank go without a lining.
Also when I started my project to paint the bike I checked out the lining first and it looked good. However as the project progressed and I was wet sanding, moisture got into the tank in spite of me masking off the outlets and filler. It was later in the process when I removed the masking tape that I saw the moisture in the tank with what looked like little zits of rust that were not noticeable before.
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Mike, we have only 5% ethanol in our fuel thankfully - so far.
My understanding is than ethanol is hygroscopic and absorbs water which is initially a good thing from a corrosion stand point but once the 0.5 % of water is exceeded phase separation occurs and the ethanol water mixture sinks to the bottom of the tank which causes the potential corrosion problem. The water doesn't come with the fuel. It gets in by condensation and I suppose the hygroscopic nature of ethanol attracts it from the air in the same way brake fluid does. Modern automotive fuel systems are a whole lot more air tight than ours which is maybe why they don't need tank linings.
I think one of the worst aspects of ethanol in fuel besides the power loss is the much shorter storage life. We all know you can't trust the stuff for very long.
I've never found more than a few drops of water in the tank when cleaning and I was only airing the absence of a tank lining as an alternative strategy together with annual tank cleaning which I do anyway with my lined tank. Who knows if the lining is 100% perfect ? It needs to be or I might as well not have it.
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Barry's got it exactly right. A couple of points to add - the design of the R65 tank, with just one tap, means that the other side can hold water trapped against the seam. I've seen two tanks rotted out along this seam purely because of water in the bottom of the tank with no escape route although in both cases the liner looked to be in great condition when examined by looking down the filler. Second point is that when a liner starts to degrade it will most likely leaves deposits in the carbs with predictable results.
I'd be happy to run with a "bare" tank and do an annual clean and inspection. Best advice would be to keep the tank as full as possible and add Sta-Bil fuel stabiliser to the petrol when the bike is likely to remain standing for more than a few weeks; this is supposed to inhibit fuel tank corrosion in addition to keeping the fuel usable.
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I just ordered my second Caswell kit from Caswell.
Its easy and quick and there are no caustic fumes to avoid. Muriatic acid and acetone to clean out the crud and then let the tank completly dry after the acetone. Watch the paint! Better to read the instructions below...
Goodluck.
http://www.caswellplating.com/aids/epoxygas.htm
Installation instructions here:
http://support.caswellplating.com/index.php?/Knowledgebase/Article/View/142/19/gas-tank-sealer-instructions
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Interesting write up Bill. Especially interesting is their mention of POR-15 and another product. So who's to know what's best??? I have already ordered POR-15 (it's in the mail) but I will use acetone to clean out the tank.
Right now my tank has been soaking in vinegar for about a week and I'm seeing lots of flaking liner inside and lots of bare metal. I guessing that I will not get all of the flaking paint out by simply draining the vinegar so I'm also thinking of flushing with water, drying it and then proceeding with the acetone and the POR products.
Also interesting is their use of drywall screws to get rust off. Right now mine looks like the vinegar had dealt with the rust.
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No worries -- POR-15 get lots of good press. I just don't like the caustic dope smells that go with products like Kreem and Bill Hirtch. You will do fine with POR-15 I suspect. [smiley=thumbsup.gif]
With ethanol its a new world in which what we knew may no longer apply. What is important is that you are doing something about it.
PS - Let me know how the POR-15 requires forced air ventilation or not.
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I'll let you know.
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Mike any progress to report on finishing up the fuel tank ?
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Hi Bob.
Yes, I finished it up. I let the vinegar sit for a little over two weeks. At first I was turning the tank every few hours to ensure I "treated" the whole tank then after about two days of this I let the tank sit for about a week without turning it. Then I turned it and let it sit for another week. After this was done it appeared that the liner was loose (I had many large flakes floating around) so I emptied the vinegar and then hosed down the inside with pressure (just hose pressure). I then dried the tank with a blow drier and then started with the kit that I had bought from POR-15. I followed their instructions. Before I put the paint in the tank I noticed I had a little flake of liner paint sitting in the crevice near the petcock outlet. I couldn't retrieve it with a screwdriver or a piece of wood so I made up a fine suction hose using tubing that I attached to my shop-vac nozzlle. This did the trick.
I applied the tank liner paint following the instructions and it all worked well. The tank has been sitting now for about 10 days and is ready for use. I did do some damage to the exterior paint and I will have to repair it or repaint it if the repair won't do the job...Other than that the re-line job was successful.
Anybody want 24 litres of used vinegar? ::)
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Guy at our local BMW shop told me to remove the red liner they fill the tank with small nuts and bolts, wrap it up in blankets and roll it in a clothes dryer for several hours. Still not sure if he was pulling my leg.