Fixing up my gas tank + effectiveness of petcock filters

[PhamNuwen]

Ok, so in the immediate absence of a suitable tank for my 82 GS650GL, I decided to try and clean out the inside of the old one--it had a poorly-done sealant application, so big flakes and chunks of sealant were peeling up and hanging all over the place. I bought a replacement petcock, one that's in better condition and has all the filter screens on it. This afternoon, I took out the petcock and fuel level sensor, sealed off the openings as best I could, and poured in a quart of acetone plus a box of drywall screws. An hour of swirling and shaking later, it actually looks pretty decent inside--there's some rust, but I'm planning on hitting that with some muriatic acid.

Now, I can't really seen any more of the sealant, but that's not to say there isn't still some left. My question here is what are your thoughts on using it like this? I could give it another run with the acetone, but since there are plenty of places inside the tank I can't see, there's never a guarantee I got it all. Since I have a petcock with actual screens this time (the PO had cut some out of the old one, I think because he clogged them with sealant), and I'm planning to put a filter on the fuel line anyway, I'd hope that there wouldn't be any sealant getting into the engine. Thoughts? Suggestions?

I also bought some xylene to try, but it's just such nasty stuff, and I think it would probably melt the rubbermaid tub I've been working out of...

 

[JEEPRUSTY]

Ok, so in the immediate absence of a suitable tank for my 82 GS650GL, I decided to try and clean out the inside of the old one--it had a poorly-done sealant application, so big flakes and chunks of sealant were peeling up and hanging all over the place. I bought a replacement petcock, one that's in better condition and has all the filter screens on it. This afternoon, I took out the petcock and fuel level sensor, sealed off the openings as best I could, and poured in a quart of acetone plus a box of drywall screws. An hour of swirling and shaking later, it actually looks pretty decent inside--there's some rust, but I'm planning on hitting that with some muriatic acid.

Now, I can't really seen any more of the sealant, but that's not to say there isn't still some left. My question here is what are your thoughts on using it like this? I could give it another run with the acetone, but since there are plenty of places inside the tank I can't see, there's never a guarantee I got it all. Since I have a petcock with actual screens this time (the PO had cut some out of the old one, I think because he clogged them with sealant), and I'm planning to put a filter on the fuel line anyway, I'd hope that there wouldn't be any sealant getting into the engine. Thoughts? Suggestions?

I also bought some xylene to try, but it's just such nasty stuff, and I think it would probably melt the rubbermaid tub I've been working out of...

is there any debris in the float bowls?
it would end up there unless your needle valves had them cool little domed screens as a secondary defense.

 

[tom203]

Are you a chemist?
Anyways,you're probably on right track by working on your own tank- search these forums for posts with folks that have done similar in a variety of methods. I scanned ebay for similar tanks and most were ugly outside and inside. A decent tank is a must to avoid petcock and carb problems.

 

[PhamNuwen]

is there any debris in the float bowls?
it would end up there unless your needle valves had them cool little domed screens as a secondary defense.

I don't know... I've been very wary of touching the carburetors at all, since I have no experience with them, and I've heard of the fiddliness of 4 synced carbs.

Are you a chemist?
Anyways,you're probably on right track by working on your own tank- search these forums for posts with folks that have done similar in a variety of methods. I scanned ebay for similar tanks and most were ugly outside and inside. A decent tank is a must to avoid petcock and carb problems.

I'm not a chemist, but the small bit of research I've done indicates that xylene softens or dissolves many different types of plastic, plus the fumes are bad business. It looks like there's decent metal under the coating, so I have high hopes.

I grabbed a flashlight and tried to get a better look inside. I think there's still some stuff in there, so I'm going to pick up a gallon of acetone and try a bit more. It's possible that the hydrogen chloride will also help clean it out.

 

[PhamNuwen]

Actually, I think I'll forgo the HCl in favor of vinegar; I've heard it can remove rust, plus I should be able to close up the tank using the petcock, gas level sensor, and cap, since vinegar shouldn't attack rubber or plastic.

 

[Nessism]

There are quite a few different threads on stripping and derusting gas tanks, you might want to try the advanced search function to gain more knowledge. I've stripped a few tanks now and in my experience high strength paint stripper works better than acetone to remove the old coating. The stripper out-gasses as it reacts with the coating so you need to allow the tank to vent while the sauce is cooking otherwise the tank will pooch out (not good...trust me).

 

[SqDancerLynn1]

I would try EvapoRust

 

[PhamNuwen]

There are quite a few different threads on stripping and derusting gas tanks, you might want to try the advanced search function to gain more knowledge. I've stripped a few tanks now and in my experience high strength paint stripper works better than acetone to remove the old coating. The stripper out-gasses as it reacts with the coating so you need to allow the tank to vent while the sauce is cooking otherwise the tank will pooch out (not good...trust me).

I've read that "aircraft stripper" aka methylene chloride can take the stuff off too; do you have a specific sort of stripper or brand name you recommend?

I also need to figure out a better way to seal up the petcock hole, the hole for the gas level float, and the cap hole. This afternoon I tried plastic caps and duct tape but got plenty of leaks... maybe I should just go nuts with the duct tape next time and try to seal it up better, because I don't really have the tools to make wooden plugs.

 

[Nessism]

I've never tried that aircraft stripper but it's reputed to be strong so go for it. You will also need a gallon or so of mineral spirits to wash down the spent stripper so you might want to pick it up at the same time. ...and while you are out, you will need some derusting sauce too; Evapo Rust works well as does phosphoric acid. ...and you will also need some new tank sealer so you might want to order some POR-15 sealer. Whew, I'm tired just typing this...but not as tired as you will be shaking the crap out of the tank full of stripper/aquarium rocks/nails/acid/ect. GOOD LUCK. Take your time and let the chemicals do their magic before moving to the next step. I've been though that hell three times so let me know if you have any questions.

 

[BassCliff]

Greetings and Salutations!!

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BassCliff

 

[PhamNuwen]

I've never tried that aircraft stripper but it's reputed to be strong so go for it. You will also need a gallon or so of mineral spirits to wash down the spent stripper so you might want to pick it up at the same time. ...and while you are out, you will need some derusting sauce too; Evapo Rust works well as does phosphoric acid. ...and you will also need some new tank sealer so you might want to order some POR-15 sealer. Whew, I'm tired just typing this...but not as tired as you will be shaking the crap out of the tank full of stripper/aquarium rocks/nails/acid/ect. GOOD LUCK. Take your time and let the chemicals do their magic before moving to the next step. I've been though that hell three times so let me know if you have any questions.

You mention a new tank sealer, but I'm wondering if I can avoid that step? Having already spent the better part of an afternoon, with more work yet to be done, getting a coating out, I'd rather avoid risking that fine and pleasant misery again. I had thought that by properly stripping out the old stuff and de-rusting the inside, following up with a prompt application of some sort of rust inhibitor (a thin coating of oil/WD40?), I could probably get away with it as long as I keep gas in the tank. Thoughts?

 

[tkent02]

Where do you live? Is it an area of high humidity? Salt air on the coast?
In some areas even empty tanks don't rust, while in other areas anything rusts up right away. Planning on letting the bike sit or riding it constantly?
Using acid or vinegar to eat the rust causes the metal to rust up again, much worse than before.

 

[Nessism]

If you use phosphoric acid as a derusting agent it will leave the tank with a phosphate coating which will protect the metal some. In fact, if you leave the phosphoric acid in the tank for several days it will leave a chalky residue which should be scrubbed off before you call it done - I like to use aquarium rocks. I've always coated after derusting just to be safe but you can always give it a try I suppose. The old saying "rust never sleeps" is true; once rust is there it's almost impossible to remove completely and even the tiniest specs will grow quickly like cancer.

BTW, photos below show how I seal a tank for stripping/derusting.

 

[PhamNuwen]

Where do you live? Is it an area of high humidity? Salt air on the coast?
In some areas even empty tanks don't rust, while in other areas anything rusts up right away. Planning on letting the bike sit or riding it constantly?
Using acid or vinegar to eat the rust causes the metal to rust up again, much worse than before.

I live in Rochester, NY, where vehicles get quite rusty, but I think it's due to the salt on the roads during the nasty winters. The humidity is high during the summer, but it's been dropping now that we're starting autumn. Also, I plan to be in Livermore, California in 2 months or so, which is a very dry place.

 

[rideOn]

the PO really effed up the tank by sealing over sand that was left inside. i had it sandblasted and a guy at the local radiator shop applied the sealer. that was over two years ago and this past winter was the first time i really had the carbs apart. outside of just a few tiny pieces of debris, the bowls were clean

 

[PhamNuwen]

Ok, so following up, I got a new tank on ebay; it looks good, the price was great, but the only problem is that I can't seem to get the cap off. On my other tank, I can open the cap with the key or a screwdriver, but on this one the lock doesn't turn. Is it stuck, or does it need a specific key?

 

[koolaid_kid]

Ok, so following up, I got a new tank on ebay; it looks good, the price was great, but the only problem is that I can't seem to get the cap off. On my other tank, I can open the cap with the key or a screwdriver, but on this one the lock doesn't turn. Is it stuck, or does it need a specific key?

You need the key to that tank lock. Take it to a locksmith and have him make you a couple. He might even be able to rekey it to your ignition key.

 

[PhamNuwen]

You need the key to that tank lock. Take it to a locksmith and have him make you a couple. He might even be able to rekey it to your ignition key.

Grr, ok. So was my old cap just broken, since I could open it with a screwdriver? That was actually kind of convenient

 

[Buster-boy]

I poured 5 gallons of vinegar into my 850 tank, let it sit for three days, then flushed everything out. My God I didn't think it was every going to stop. Worked like a charm but the downside to this (and I don't know if anything else would have helped) is you have to rinse it with salt water.

Salt neutralizes the acetic acid, which is what you want, but after you rinse it you get a super light coating of rust. Not much you can do about that I guess. Anyway, I dired it real quick then selaed it with Red Kote. Tank looks great inside and nothing is coming through the fuel lines. Total cost - about $12.00.

I should add that the tank had not been sealed previously so I didn't have the issue you do. I doubt vinegar would work on that.

Jim

 

[waterman]

I poured 5 gallons of vinegar into my 850 tank, let it sit for three days, then flushed everything out. My God I didn't think it was every going to stop. Worked like a charm but the downside to this (and I don't know if anything else would have helped) is you have to rinse it with salt water.

Salt neutralizes the acetic acid, which is what you want, but after you rinse it you get a super light coating of rust. Not much you can do about that I guess. Anyway, I dired it real quick then selaed it with Red Kote. Tank looks great inside and nothing is coming through the fuel lines. Total cost - about $12.00.

I should add that the tank had not been sealed previously so I didn't have the issue you do. I doubt vinegar would work on that.

Jim

I can't figure why you would neutralize acid with salt water, it isn't akaline, baking soda water would work to neutralize if you wish. Salt water would tend to cause it to oxidize and rust again. Plain tap water would work just fine also. Dilution is the solution.