fuel tank restoration

[70GT]

I need to reline the tank on my 85 700 . Wanted to get some input on what product to use looking at por 15 or kreem . Also any tips or things to beware of would be cool thanks 70GT

 

[chuck hahn]

Between those two..Por 15 hands down is my opinion. Search feature has many wyas to derust..vinegar, acylic acid, electrolosis..many many ways. Type in key words and hit GO.

 

[JEEPRUSTY]

Derusting a tank with chems is wrong.

Making the matter worse by applying a coatling is more worser still

Mechanical cleaning with ittly bitty rocks is cool.

Removes the offensice cloggy stuff and does not etcht eh tanks and create an ever increasing surface area for more rust ot occur upon.

 

[Big T]

Derusting a tank with chems is wrong.

Making the matter worse by applying a coatling is more worser still

Mechanical cleaning with ittly bitty rocks is cool.

Removes the offensice cloggy stuff and does not etcht eh tanks and create an ever increasing surface area for more rust ot occur upon.

Have to disagree with you on that.

It's impossible to completely derust with rocks. They just won't get into any craters

Coatings are fine, I have 2 tanks I Keemed in the 80s that are still fine

To the OP, prep is everything. Take your time and soak the tank for hours with whatever you use. I'm going to try the vinegar method on my next tank, as you don't need to create block offs for the sending unit and petcock.

 

[Graham]

Derusting a tank with chems is wrong.

Making the matter worse by applying a coatling is more worser still

Mechanical cleaning with ittly bitty rocks is cool.

Removes the offensice cloggy stuff and does not etcht eh tanks and create an ever increasing surface area for more rust ot occur upon.

Chemicals are fine for cleaning as long as the chemicals are cleaned out of the tank. Rinse, rinse, rinse then dry.
Tank coatings rarely last and some can cause some real issues. Not worth it.
Rocks and BBs are too time consuming and don’t do as good as the chemicals.

Just my opinion.

 

[chuck hahn]

By dry i think Graham also means to dry it as fast as you can to prevent flash rust inside. I use the shop vac and reverse the flow so its blowing.. I hold the hose over the filler neck for a while and it drys the tank out very fast. thing is to not let it air dry. Youll look in and see the brown all over again.

 

[Nessism]

There are dozens of long threads on this exact topic in the archives. A simple search will produce more info than most people have the patients to read though.

Using the Advanced Search feature works great, particularly if you limit the search to Titles Only.

Bottom line is Por-15 is far superior to Kreem. Best to derust before lining. If the tank is lightly rusted, you can derust and leave it at that. With heavy rust, the cancer will come back without a liner.

 

[chuck hahn]

Hey Ed..just a thought and question..Have you heard of or seen any derusting and coatings for the undersides of tanks? Seems thats an area that gets abused a lot as well. Lining the inside is a plus, but what about stoppind rust eating inward from the outside?

 

[Nessism]

Hey Ed..just a thought and question..Have you heard of or seen any derusting and coatings for the undersides of tanks? Seems thats an area that gets abused a lot as well. Lining the inside is a plus, but what about stoppind rust eating inward from the outside?

Killing ALL the rust is recommend. There are all kinds of methods to do so including acids, sand blasting, and sealer paints (such as POR-15). On my seat pan I sand blasted all the rust off best I could but there was still rust flecks down into the pits in the metal. After blasting I used POR-15 paint to seal down any remaining rust. POR-15 claims you can seal over rust but I'd rather remove as much as possible before sealing just to hedge the bet.

 

[Hammered]

Electrolysis is the best way to go. 1/2 cup of wash soda to 5 gallons of water and 24 hours in the bath with a battery charger. Id follow up with a quart of MEK and a hand full of short drywall screws and shake. Let it dry and reline the tank. Itll take all weekend but its easy.

 

[Nessism]

Electrolysis is the best way to go. 1/2 cup of wash soda to 5 gallons of water and 24 hours in the bath with a battery charger. Id follow up with a quart of MEK and a hand full of short drywall screws and shake. Let it dry and reline the tank. Itll take all weekend but its easy.

Yes, more than one way to accomplish the same task.

Personally, I'm not so keen on electrolysis for a gas tank because you need line of sight from the rust to the electrode and it's hard to see if all the rust is removed.

 

[chuck hahn]

I was just wondering about the outside. I have seen stuff with names like rust stop and such and always wondered if they actually stopped reaction of rust on the outer surfaces..

 

[Graham]

By dry i think Graham also means to dry it as fast as you can to prevent flash rust inside. I use the shop vac and reverse the flow so its blowing.. I hold the hose over the filler neck for a while and it drys the tank out very fast. thing is to not let it air dry. Youll look in and see the brown all over again.

Yea dry with shop vacuum, leaf blower, air hose. As for flash rust, I like to put a quart of 2-cycle oil in the tank and coat the inside then drain before filling with gas. It may smoke a little for the first tank full but after that it is fine.

 

[chuck hahn]

I good sloshing of diesel or kerosene will coat the insides with a filmy oil..just a rinse with gas before installing the tank will also do the trick to prevent flash rust after drying it out..theres a lot of inventive ways to skin the cat.

 

[ChickenGutz]

Electrolysis is the best way to go. 1/2 cup of wash soda to 5 gallons of water and 24 hours in the bath with a battery charger. Id follow up with a quart of MEK and a hand full of short drywall screws and shake. Let it dry and reline the tank. Itll take all weekend but its easy.

Hey Hammer, would you describe the electric method? And what is 'wash soda'? I'm 60 and never heard of that. :|

 

[dueller]

Link for ya

Link for ya

Hey Hammer, would you describe the electric method? And what is 'wash soda'? I'm 60 and never heard of that. :|

Check out this link http://katriders.com/vb/showthread.php?t=95247

 

[Hammered]

Washing soda is just sodium carbonate. Arm and Hammer sells it by the box for cheap. It only takes about a 1/2 cup to every 5 gallons of water. I just tried this out on an old garden pump can. To get the line of site, I hung the donor electrode in the can itself. Course I have a bore scope at work so it made it easy to check after a couple days sitting.

All you need is a large enough non conductive tub like container, water, washing soda, electrode for attracting the rust, battery charger oh and something rusty.

 

[1948man]

70GT, you say "reline." If you mean that literally and there is a failed liner in your tank, the plot thickens. Getting out a failed Kreme job is difficult. I used the molasses trick to derust my tank and it works great if you aren't in a big hurry (just Google "molasses,rust"). Ditto on the need to put something in the tank to prohibit flash rust after you get the rust out. Search on this site for Caswell for another coating option which worked perfect for me. If you get a little flash rust, you can just coat right over it.

 

[tkent02]

I have done about ten tanks using electrolysis. It gets them clean, but it takes some time and effort. Apparently while wet sanding I got some water in the 650 tank I just painted, it's a little rusty inside now. Guess I'll be doing the electrolysis again. Just a tablespoon or so is enough soda for several gallons, it is not part of the chemical process, it is only there to make the water conduct electricity better.

 

[BassCliff]

Hi,

I'll share my de-rusting experience too, what little of it there is.

Tank Cleaning: with Evapo-Rust (PDF file)

After cleaning with Evapo-Rust, I did not line my tank with anything. It's still rust-free after a year.
​

Thank you for your indulgence,

BassCliff