muriatic acid - top of rusty tank?

So I acid washed my tank last night and am wondering if I should have put something in the gas cap hole and flipped the bike over. I just filled the tank as high as I could get it and let it sit overnight. Is it alright that the top of the tank is probably still rusty? Isn't rust like cancer and will it just spread back down?



Re: muriatic acid - top of rusty tank?

Zack Rineer /

I have done two tanks.

First muriatic acid, then let tank dry, then use this stuff called kreem... a tank sealer..

You might have to redo the muriatic acid, because most likely you will have some rust come back from the air hitting it...

Re: muriatic acid - top of rusty tank?

you have to seal that shit!!! i did a 3 step process on my maxi. the cleaner... the acid and then the silver metallic coating that fills and seals the tank from rusting again. it also neutralizes any future oxidation. Do it. you will be happy you did

it is by POR 15 US standard fuel tank sealer!

here is the link to the website. your local auto paint store should carry this.


Re: muriatic acid - top of rusty tank?

hmm after reading a lot of posts it didnt seem like a sealer was necessary so I just did the fill the tank with oil thing after.

Back to my original question, is it necessary to get the top of the tank? or does it not really matter since the gas is at the bottom?

Re: muriatic acid - top of rusty tank?

i second por-15. first time anybody sees a freshly done por-15 tank they are like "holy shit!" it is like a brand new tank.

Re: muriatic acid - top of rusty tank?

damn right. the last thing you want is a brand new paint job that pisses a tiny stream of gasoline out the side in a few months.... think of it this way-

you spend all that time shaking soaking and shaking that acid some more to break down that rust and corrosion. all that flaky shit you just dumped out was holding your 30 year old tank together. Most likely the thin walls of your tank are a hell of a lot thinner than they were. YOU HAVE TO SEAL IT!!! urghgh its like 15 minutes of work and a couple days of drying time that will make your life sooo much better.

to answer your main question about the top portion of your tank.... try your best to get that stuff knocked down. but it doesnt really matter now that you took a short cut. just get yourself a handful off petcock filters and some duck tape to seal the sides.

Re: muriatic acid - top of rusty tank?

lol ok

so if I degrease the tank again and put more acid in and try and get the top part for like 30 min then seal it. I'll be good?

Would NAPA have Por-15? or has anyone used Red Kote?

Re: muriatic acid - top of rusty tank?

I dont know if napa would have it... if they do it will be like a freaking 5 gallon kit for cars!!! and you will pay for 5 gallons! try a motorcycle shop. or if you have a "warehouse paints" near you, they will have it. i have heard of red kote, kreem all those are basically the same. and insoluble sealer. i use por15 because it is local to me. one note.... MAKE SURE YOUR TANK IS COMPLETELY DRY before pouring in the sealer. also... since you said you already poured oil in there you will have to acid clean it again before you coat. sorry but you have to re clean it out now!

most kits will have the cleaner the acid and the seal for like $50. you can run what you have just be cautious of the condition it is in now. if its not too bad you may be alright. hope that helps man

Re: muriatic acid - top of rusty tank?

could someone briefly run through the process of cleaning with muriatic acid especially concentrarion of acid and length of time left in tank

Re: muriatic acid - top of rusty tank?

Use it straight out of the bottle. Let it bubble and then let stand for 2 hours. Depends on how thick the rust is. You can pour a bunch off Coca Cola afterwards to put a phosphate coating on the metal. I got a load of epoxy garage floor coating free and it says it is impervious to all auto chemicals and so far in my tests of the cured product that claim has rung true.

Re: muriatic acid - top of rusty tank?

a por 15 motorcycle tank kit is 35 bucks usually from the site (marine clean, metal ready, por-15).

they also sell the zinc phosphate/phosphoric acid solution you could put in your tank called metal ready.

Re: muriatic acid - top of rusty tank?

I pretty much followed the wiki

except I used the muriatic acid as I bo

ught it from home depot and let it sit overnight. And instead of using the alcohol I just blowdryed the tank and filled it with oil to coat the inside.

Although the Por-15 kit does sound like it would be good if I did it again.

Re: muriatic acid - top of rusty tank?

Gooch Warmer /

Just did the muriatic acid and it cleaned my tank pretty well, it was also strong enough to eat thru my fuel petcock so drained itself letting me know it had enough...

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