gas tank sealant

[DM8761]

is it necessary to really apply some type of a sealant to the inside of gas tank?

after a recent carb cleaning and getting replacement jets, do to a semi rust gas tank, the powdery rust not the big flakey chips and such.

im pretty sure they dont do anything to them once they leave the factory, an old timer friend of mine, who actually worked at the kawi plant her in lincoln ne back in the day. told me that all they did was put this spray stuff in the tank while its on the assy line, he told me it was the equivilant of wd40, and the only purpose they did it was just to keep it from rusting before it got to the dealer ship, and it got its first tank of gas.

i mean really... like the tank lasted 30 years the first time, i dont see why it wouldnt last another 30, the rest of the bike isnt going to last another 30 years. i am planning on doing the rust remover thing, leaning towards the Metal Resuce brand of cleaner. Then im just planning on putting gas in it, and if the bike is parked for more than a few weeks, just make sure its topped off... (which you should do anyway)

The bike is a 1982 kawi GPZ550, its basically a learner bike for my GF, before i let her get her ninja. i picked i up for 300 bucks do to "carb" issues... lol

any thoughts gentleman?

[cowboyup3371]

I really don't know anything about the Kawasaki, especially since I have a Suzuki GS, but I would think you should still seal the inside to prevent the future re-occurrence of rust. Just kinda makes sense to me just in case especially since some of those materials can flash rust.

[BassCliff]

Hi,

It depends on how badly rusted the tank is. If you get it clean enough (there are tank cleaning guides on my little website) and keep gas in it, it may not rust again. But if it does rust you'll be gumming up your carbs and petcock. The proper fuel filter might help but could cause fuel starvation.

I will say that I did not coat my tank after de-rusting it with Evapo-Rust. But you will have to make that call according to your situation. If it is rusted too badly such that it's flaking off, then you may have to coat the tank.


Thank you for your indulgence,

BassCliff

[sedelen]

I did not seal my tank before I had it repainted. It didn't leak so why bother? That was a mistake I'm still paying for. On the GS1000 there's an indent underneath the gas cap. Water collects there and it did cause some
superficial rust to the outside of the tank there. But all that was taken care of when the tank was repainted, or so I thought. I soon started getting these "bubbles" in the paint underneath the cap. Thought it was
gas getting underneath the seal, but finally figured out it wasn't. I had the tank redone again, and the bubbles came back. So what was causing the bubbles? Seems like the rust under the cap on the indent was enough to make that area a "little" pourus in a couple of places. When pressure built up in the tank, the fumes bubbled up from the inside of the tank.
I'm still using that tank, haven't quite decided what to do with it, and I have another painted tank to replace it with. But had I sealed it to begin with I woundn't have had this problem to begin with.

[DM8761]

Yes i have a few GS's also.. techinaclly 3 gs's and 1 gn, and yes they're all running, rideable, licenced, and insured.

But like i said this kawi is a learner bike for my GF, and i picked it up super cheap, and its a decent looking little bike. Shes not learning on any of mine... lol

..anyway, yeah im not sure as to what im going to do... it doesnt leak, theres no swelling or anything of the out side paint. And the rust wasnt that bad... it was the powdery surface rust that you can rub off with your figher.. but the whole insdie was that way. I have this make rust go a way stuff, ur supposed to soak it in, and it says that it wont let it flash rust, ill prolly just de-rust it, put it back on the bike, fill it full of some 90oct and put a filter on it.. lol if she gets a couple summers out of it it'll make her happy

[AJ]

I am sold on KBS Coatings - a very complete kit that will not leave you feeling sorry you used Kreem.

http://www.kbs-coatings.com/cycle-tank-sealer-kit.html

[old_skool]

I am sold on KBS Coatings - a very complete kit that will not leave you feeling sorry you used Kreem.
http://www.kbs-coatings.com/cycle-tank-sealer-kit.html

Not to hijack the thead, since it will be helpful to him as well, but is this stuff that good, do you have experience using it. Price is right.

[Big T]

I haven't used this product, but it derusts and coats all in one easy step (so it claims)

http://www.youtube.com/watch?v=Hb7jyf7A4WE

[old_skool]

Yeah, I've heard of Metal Rescue, supposed to be pretty good, about $25, I was going to use Evapo-Rust, looks to be about the same thing, can be bought at auto parts stores for $19.99

[tkent02]

I haven't had to coat any tanks after de rusting them, they never rust up again.
But I don't live in a humid environment and let them sit half empty for years, either.

[AJ]

Not to hijack the thead, since it will be helpful to him as well, but is this stuff that good, do you have experience using it. Price is right.

The KBS kit is very complete. There is a cleaner to remove old gasoline varnish. Then an acid etchant that eats the rust and also leaves some kind of chemical coating to stop future corrosion. Finally you overcoat this with the polyurethane plastic coating. Polyurethane is what they use on gas tanks for modern airplanes. Unlike some earlier coatings, it resists the methanol alcohol in modern fuels.

I have now done 4 (maybe 5) tanks with the KBS kit. Don't be surprised if the etchant doesn't eat a rust hole through your tank and it starts leaking for real (had this happen once sealing a tank on a 2002 Katana 600). Don't worry, as you can use a mesh with the polyurethane to seal up even large holes. If you think your tank has actually rusted through, then order the mesh with your kit.

The downside of KBS is that this is a LONG process. It takes about a week from start to finish before you can use the tank. But it's not hard to do and it does work.

KBS also sells an etchant if you need to first remove a botched sealant job like Kreem.

[1_v8_merc]

You can run with light to moderate flash rust.
It's an oldschool technique called "burning it out", lol.

I did it on my 650, till it was all gone.
Took roughly 5 or 6 fill-ups till it was gone completely.
Never really had any problems....I ran a secondary filter just to ensure nothing bigger got threw.

You may get a hiccup every once in a while, at idle.
But for the most part, if you keep fresh gas In there, it'll run.

I'm sure this is not the "politically correct" answer most people will agree with...but You asked about flash rust! lol