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Login to post Forums » Sprockets » Fuel tank sealers

June 5, 2011 7:48 a.m. 1988RedT2 Dork

Well, after Friday's ride, I decided I would procrastinate no longer and go ahead and pull the tank, clean it out, seal it, and paint it. It's distracting, and just not that much fun to have the bike stalling out (or trying to) every time I come to a stop, particularly in traffic. I have ordered the kit from POR-15. I have used some of their products before and they seem to work well.

Anybody got any tips/advice for a successful job? From what I've already read, preparation is everything. No surprise there.

Thanks for anything!
June 5, 2011 7:58 a.m. Dr. Hess SuperDork

"I've heard" that when cleaning the tank out, dump a package of steel BB's in and shake it around to knock the rust loose. Others suggest a length of chain.
June 5, 2011 9:21 a.m. 44Dwarf Dork

If your going to paint the outside. Remove the rust inside to bare metal.

http://antique-engines.com/electrol.asp

if you dunk the whole tank some of the pait will come off. some have used the tank as the container with out messing up the paint but i've never tried that. Google it.
June 5, 2011 6:42 p.m. 93EXCivic SuperDork

I have heard very very mixed opinions on sealing gas tanks.
June 5, 2011 6:55 p.m. triumph5 Dork

This might be nieve, but, being a bike tank, couldn't you just drain the fuel, steam clean/simplegreen/Dawn-soap the tank to get all the gas fumes out, then pressurize it with like 3-4psi, and weld the holes or the seam? Or is the tank just haning in there metal wise, and this is a method to retain a tank that'll be hard or expensive to replace? Just wondering.

I've used POR-15 with great success sealing metal keels on sail boats in salt water.(metal being cheaper than lead, it was often used, and one learned to live with rust....) GREAT stuff. Lasts for years, and you're right. PREP, PREP, PREP, and follow the instructions to the letter.
June 5, 2011 7:57 p.m. MitchellC Dork

I have also heard of plugging the petcock and filling the tank to the brim with muriatic acid and allowing it to eat up the rust.
June 5, 2011 8:24 p.m. fasted58 Reader

MitchellC wrote:

I have also heard of plugging the petcock and filling the tank to the brim with muriatic acid and allowing it to eat up the rust.

Muriatic acid will absolutely devour rust but maybe no need to fill the entire tank, although it is cheap enough. Fill 1/4 tank or so and rotate every 15 minutes till all sides have been burnt out. Rinse thoroughly w/ plenty of water. Don't use full strength on pot metal or aluminum parts. Dry thoroughly and be ready to coat w/ sealer as the now cleaned steel surfaces will start to oxidize almost immediately.
June 5, 2011 8:38 p.m. 1988RedT2 Dork

Just a little more info. The tank in question is from my '76 KZ400. It's really in pretty good shape. Still has the original factory paint on it, but it's a bit faded, as you might imagine. Getting a new tank is bound to be all but impossible, since even basic maintenance parts are hard enough to find. There are no holes, but a bit of rust and crud inside the tank. I have filters in the fuel lines, and they are trapping plenty of rust flakes, but apparently are letting smaller pieces through that are still big enough to clog passages in my carbs. I've had the carbs apart several times, and the bike runs great for a while, then starts acting up again. I'd like to limit my carb cleanings to once annually, if possible. Not every other week.
June 5, 2011 10:30 p.m. 2.0dohc Reader

I used Kreem gas tank sealer on a bike a few years back, had good luck sold it 3 or so years later and never had a problem. Just follow the label.

edit:...If you do use BBs or the like, either weigh or count what goes into the tank and what comes out, wouldn't want to leave any in.
June 5, 2011 11:08 p.m. fasted58 Reader

Why don't ppl like using Muriatic acid?? As long as you use it safely outdoors it's the tits. I'll hafta post some before and after pics of crappy rusty metal... if I can figger out how to post .jpgs from the dark side of my computer pic files.
June 6, 2011 9:35 a.m. 44Dwarf Dork

Let me say this I'm not opposed to sealers but use them only when theres a pin hole to seal. When there is I'd choose between Caswell platings kit that is thick and almost fibrous and high dollar aircraft stuff from aircraft spruce. Todays fuels kill most everything. Do don't see airplanes falling out of the sky often....TG! But $200 to seal one tanks to much if you've got a few tanks to do no big deal.

Sealing is last resort to me. If its just minor rust two boxes of 1/4 external star washers and a box of 1/4x20 nuts an a cup of acetone and shake until your arms fall off. dump, rest, refill repeat twice more. rinse and done.
June 6, 2011 2:38 p.m. DustoffDave Reader

If you don't want to use the muriatic acid you can also just use 100% distilled white vinegar (about $1.50/gallon at the supermarket) and let it stay in the tank a little longer than you would for the acid (say, 24 hours or so, rotating/shaking it every few hours). Make sure it's all flushed out when you're ready to seal... I have the Kreem sealer in my tank and it's never given me any issues.
June 7, 2011 5:36 a.m. 914Driver SuperDork

I've used this stuff about a bazillion times with good results.
June 7, 2011 6:15 a.m. foxtrapper SuperDork

I'd rather not waste my time shaking a tank. So I tend to fill it with vinegar and let it sit there for a few days. Then I rinse it out with water and admire the sparkly clean and rust free interior.

Those that are more masochistic will waste time and effort with rocks and such in the tank. Since my method works better and takes less effort, I don't see the point.

As for liners, they don't come OEM with it, for a reason, and it's not just cost savings. When the liner starts flaking off, you'll understand.
June 7, 2011 9:18 a.m. 93EXCivic SuperDork

foxtrapper wrote:

I'd rather not waste my time shaking a tank. So I tend to fill it with vinegar and let it sit there for a few days. Then I rinse it out with water and admire the sparkly clean and rust free interior.

Those that are more masochistic will waste time and effort with rocks and such in the tank. Since my method works better and takes less effort, I don't see the point.

I am using the shaking method to break off the tank liner in my tank.
June 7, 2011 9:35 a.m. 44Dwarf Dork

some people report a slurry called "Milk Stone" works great for rust and linner removeal but i've not tried it yet.
June 7, 2011 9:46 a.m. 93EXCivic SuperDork

44Dwarf wrote:

some people report a slurry called "Milk Stone" works great for rust and linner removeal but i've not tried it yet.

I am going to try it once I get all the old tank liner out of my tank to get the rest of the rust and crap.
June 7, 2011 1:19 p.m. 1988RedT2 Dork

Well, I got my stuff from POR-15 today. Maybe I'll just do the first two steps and not apply the sealer, but I think once I have it clean, I'll want to seal it to keep it from rusting up again. I've gotten to trust their products.
June 7, 2011 4:48 p.m. 44Dwarf Dork

As long as you follow to the letter it should work but don't expect 20+ years out of it with the EPA changing the chemical soup...P4 gas.

P 4 gas say it one letter at a time..... P 4
June 7, 2011 8:42 p.m. Rusnak_322 HalfDork

44Dwarf wrote:

As long as you follow to the letter it should work but don't expect 20+ years out of it with the EPA changing the chemical soup...P4 gas.

P 4 gas say it one letter at a time..... P 4

No kidding about the P 4 gas. I have a plastic tank that was lined to prevent the ethanol from destroying the tank.And this is in a newer bike.

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