Rust revisited

[chiphead]

Has anyone had any experience with either Rust Solve (http://www.cleanrust.com/) or Rusteco (http://www.rusteco.com/) for cleaning fuel tanks?
Thanks.

[b1ackd3ath]

There was a recent thread about phosphoric acid being the best and then neutralizing it with washing soda or something similar.

[lord1234]

use either Kreem/por15 or the phosphoric acid trick. I have phosphoric acid if you want some...

[chiphead]

Thanks black and lord. I've read until my eyes bled on this subject and have even talked to a couple of radiator shops. In the middle of all this up pops a brand new gs1100g tank on ebay but it went for 300 which is out of my range. Anyway, I'll figure out what I'm going to do. The phosphoric acid seems to compromise the metal and promotes instant rusting if not taken care of immediately, plus it's a friggin acid!

[b1ackd3ath]

Checkout my comments on electrolytic rust removal in this thread:

http://www.thegsresources.com/_forum/showthread.php?t=96924

There are some good links to pages that have pictures of it.

[lord1234]

steve, what do you think that POR15 or Kreem are? They are 3/2 step...Here are the steps:

Acid
Neutralizing agent
Coating

The coating tries to avoid future rust for when you forget to keep your tank full or leave it lying around for another 20 years...

Acid = phosphoric acid
Neutralizing agent: Baking soda

[Jethro]

I used the phosphoric acid trick myself based on Leo's comments and Billy Ricks I think, that stuff works like a charm. I didn't enconter any instant rust at all, and it's holding up nicely. Mine was only slight powdery surface rust though, don't know what any real flakey stuff would do.

Don't get any on your skin, holy fuc%, I just about freaking passed out when I got it all over my hand with a fresh wound from earlier the same day.

One lsat thing, I used the Kreem kit before, and it failed, but I may have done a crappy job.

[tomcat24551]

A couple of questions, guys:

Did the factory coat the inside of a new gas tank with anything to try to prevent rust, at least for a little while? If so, anybody know what it was?

Has anyone ever tried to remove rust from the chamber at the top of the metal airbox where the crankcase fumes (filled with sulphuric acid, I suspect) get sucked into the airbox thru the rubber hose? Then, they condense on the cold metal airbox. My '79 850 has rusted badly inside the metal nipple in the airbox and in the upper chamber, too. I think I'm going to use Evapo-Rust (thanks to the idea I got from this forum!) to clean it out, but I'd like to coat it with something like Kreem once I get it back to bare metal. Anyone have a recommendation on what to coat it with?

Thanks for any ideas.

[Billy Ricks]

Phosphoric acid available at Home Depot in the paint department does the trick. You can get a gallon for about $13. I used it straight out of the bottle without hurting anything. First I rattled some pea gravel around in the tank to knock stuff loose. Then threated it with the phosphoric acid for about 20 minutes. One huge chunk about 2" long, 1/2" wide, and 1/8" thick came out along with alot of little stuff. I didn't think my tank was all that bad either. I flushed the tank with a garden hose and used a blow drier to dry out the moisture. I repeated the wash again just for grins. A little more rust did come out. At the end I used a combo of naptha and motor oil as a final rinse to protect the tank until I'm ready to refill it. Just drain the solution and when the naptha evaporates you'll have a thin coat of oil left behind.

[retrex]

Por 15 store US standard tank sealer kit is what you need. It comes with directions which you need to follow to the letter. Kreem is crap, stay away from it. See my post on Painters advice needed for how to clean and seal a tank. Good luck.

[chiphead]

Phosphoric acid available at Home Depot in the paint department does the trick. You can get a gallon for about $13. I used it straight out of the bottle without hurting anything. First I rattled some pea gravel around in the tank to knock stuff loose. Then threated it with the phosphoric acid for about 20 minutes. One huge chunk about 2" long, 1/2" wide, and 1/8" thick came out along with alot of little stuff. I didn't think my tank was all that bad either. I flushed the tank with a garden hose and used a blow drier to dry out the moisture. I repeated the wash again just for grins. A little more rust did come out. At the end I used a combo of naptha and motor oil as a final rinse to protect the tank until I'm ready to refill it. Just drain the solution and when the naptha evaporates you'll have a thin coat of oil left behind.

Did you remove petcocks, fuel sending unit etc?