Kreem gas tank woes

This site's directions call for phosphorus after meriatic. is that good to do?

Won't hurt it.

The phosphorus is a base element designed to neutralize any acidic holdovers in the tank. Basic pH stuff. P(15) has no rust preventitive qualities that I'm aware of. I'd just flush the bejesus out of it, let the tank dry out in the sun, and get on with life.

But then again, *anything* you stick in that tank will do less damage than plain old water in the long term.

Yeah, i'd like to avoid water, but what do I do arter meriatic?

I can tell you what happened after I used muriatic acid. It showed shiny clean metal in the inside of the tank which pretty much started to flashrust immediatly.

I then used a solution based on phosphoric acid ( rustconverter from Lowes )which caused the rust to be converted into iron phosphate ( bluish, black firm surface ). After draining and flushing the tank with acetone I coated it.

I didn't use Kreem though not sure of the steps for coating with that, it may be different.

One more thing, if you use muriatic acid and you have a hole in the tank that was closed with bondo it might eat through it, don't ask....

I've done quite a few tanks with Kreem. I'm not sure what ratio of muriatic acid/water is needed, but for me it worked best mixing strong. I think I did about 50/50 mix with water than had enough mixture to fill the entire tank, then let it sit overnight.
Don't rely on tape to seal your petcock, it won't work. If you have the conventional petcock setup with 2 bolts securing it to the tank, remove the petcock, get a thin piece of wood or similar and drill it so you can use your existing petcock bolts to tighten it snugly to the tank covering the fuel outlet. A homemade plate in other words. If you have the large pipe thread petcock simply plug it with a large cork.
Lastly, when you do put the Kreem in the tank, swish it around to be sure you've coated the entire tank, let it sit a few minutes then repeat. Now drain the Kreem out of there before it turns to a 1/4 thick mess you can't drain and you're done. Be sure and get the kreem out of there before it sets up. You don't need or want a real thick coating of this stuff, just enough to seal the tank.

KZPens wrote:

I can tell you what happened after I used muriatic acid. It showed shiny clean metal in the inside of the tank which pretty much started to flashrust immediatly.

I then used a solution based on phosphoric acid ( rustconverter from Lowes )which caused the rust to be converted into iron phosphate ( bluish, black firm surface ). After draining and flushing the tank with acetone I coated it.

I didn't use Kreem though not sure of the steps for coating with that, it may be different.

Ah.

Flash rust will appear at a varying rate, depending on a number of factors; relative humidity and how much water's in your water, so to speak, are the biggies. Some city waters have traces of stuff in 'em that would freak out rocket scientists, and some well waters have enough iron them to make a mold, pour it in, let it set overnight and you have a new tank. High-iron content waters promote rust. I use a carbon filter and a reverse osmosis setup, so I don't notice it as much, I guess. I also blow out a treated tank with compressed air after flushing to get the drying process going ASAP. I have seen flash rust develop within an hour on damp surfaces, though.

I *like* the phosphoric acid idea. Neat stuff. Didn't think of it, my bad. I'd go for it.

Also very true is the sow's ear/silk purse scenario; if your tank is junk to start with, the muratic treatment will tell you in a hurry. If you treat your tank and it springs a leak, consider it a good thing that it didn't start out on the road somewhere 100 miles from home, make the old one a paperweight and get a good one.

I have have nothing against the people that make that Kreem (tm) stuff; it seems an honest effort to make the best of what's already an *iffy* situation to begin with. Silk purse/sow's ear. I just haven't seen much sucess with it.

Arg....my tape gave way and it leaked out whiles i was away, now there's more rust than before muriatic. I'll try the wood idea, but this isn't good. what do i do after muriatic to avoid this? flush with acetone. fill with gass after acetone flush?

frustrating

It's well-nigh impossible that *flash rust* - the fine red oxide that develops in a humid environment after a chemical treatment like muratic caused what you think you're seeing within hours of application.

At most, there's a *thin* layer of flash with clean metal underneath - it's more likely that you had one *really* rusted tank there. Rust promotes rust.

1. Find a way to seal that puppy up. As you've discovered, tape won't get it done.

2. Give it another shot of muratic. Keep doing it until it's clean.

3. Have a gallon or two of *distilled* water ready. A couple bucks or so.

4. Flush with distilled.

5. Blow it dry with compressed air.

6. Dump in the "Rust Converter" (Phosphoric Acid solution) and do "The Swirl Dance."

7. Flush with acetone. More Swirl Dance.

Thanks for providing a clear plan.

Funny, it was never this bad before. even eafter 2 years with 1/2-1/4 tank full of gas.

Why do you call rust flash?

guavatone wrote:

Thanks for providing a clear plan.

Funny, it was never this bad before. even eafter 2 years with 1/2-1/4 tank full of gas.

Why do you call rust flash?

Believe is or not, it was *ALWAYS* that bad. Rust isn't like mushrooms or '50's B movie monsters; it doesn't grow in mass exponentially in mere hours - rust takes time to deeply integrate itself into the crystalline structure of metal and convert it to an oxide.

That thin coat of orange-ish oxide that appears on freshly-etched metals is called "flash rust" because literally, it appears in a *flash* - within minutes or hours of exposing fresh metal to air.

It is rust, but it's a slightly different animal because it's not deeply engrained in the metal - yet -you could wipe most of it off with your finger. Leave it in there and it'll grow eventually, but it's no real problem if you get at it quick.

Here's a definition:

( www.advisorycouncil.org/ILC/Glossary.htm )

"Flash rust, is an oxidation of the steel that occurs, within minutes, as the water is drying. Flash rust is also the rusting of steel as a water-borne coating is drying.

Steel naturally oxidizes when water is present. Flash rust quickly changes appearance to a rust bloom or water bloom over a large surface area. The color of the flash rust may vary depending on the age and composition of the steel and the time of wetness of the substrate prior to drying. Drying with hot air blowers or the use of the vacuum systems can reduce or eliminate the flash rust."

stange thing is that when I did my first muriatic cleanse, the rust by the top opening cleaned and was all grey, Now... I have a muriatic and distilled water almost full to let it soak and when I came back an hour later the metal by opening flash rusted a tad.

Should I bother leaving it to sit with muriatic or shoud I just do it in less time with a few muriatic flushes and try to get to the phosphorus stage (no water) quickly to avoid any flash rust?


almost there, oh the wood is working like a charm but not on the sensor holse so I put the sensor back in - hopefully it won't disintegrate!