Krud Kutter - Rust Remover and Inhibitor

[Donald]

I tried some of this stuff on the seat pan of a Bobcat where there were some rusty areas and some painted areas. I used a small wire brush and a steel wool like pad to remove anything loose. Cleaned with alcohol. The stuff went on fine. The directions saw to wipe it off and rinse after 15 minutes unless you want a protective coating that will last up to 1 yr, in that case let it dry. I let it dry. Some areas turned white (probably over existing paint) and some areas stayed dark. Not sure what to think. I certainly do not see all the rust removed. My plan next is to spray some Amsoil Heavy Duty Metal Protector over this area and then reinstall the seat.

 

[mechtech2]

How about some old fashioned Naval Jelly? it is a phosphoric acid [pink] in a gel form. Sold in bottles.
Brush it on, and rinse with water 15 minutes later. Repeat if necessary.
Cheap, and will get you down to a no rust metal condition.

 

[Donald]

Originally Posted By: mechtech2
How about some old fashioned Naval Jelly? it is a phosphoric acid [pink] in a gel form. Sold in bottles.
Brush it on, and rinse with water 15 minutes later. Repeat if necessary.
Cheap, and will get you down to a no rust metal condition.


I was hoping not to get into all that. I thought this stuff was like Extend. Maybe its not. Given I have more painted areas than rust areas I just wanted a decent surface for the metal protector I want to spray next.

 

[ltslimjim]

Is a CLR or another 'quick' rust attacking product worth it without a solid sealant coat down afterward?

Amsoil's HD MP is awesome, by the way. In place of a true re-seal(prime only?) it would probably last at least 6 months outdoors exposed to the elements. It'd be a shame if the rust didn't come out all the way and would prefer to get it all taken care of if the first step or removal wasn't truly completed. Just saying, but perhaps it's negligible. I am new so educated me please.

 

[Donald]

I can give it a coat of paint if that is what is needed. I was hoping the Amsoil HD MP would provide the protection. About 90% of the area is under the seat so its somewhat protected from the weather. My impression is that the Krud Kutter stuff will convert old rust and form a barrier against new rust.

 

[mechtech2]

It is actually very easy to use naval jelly.
Swab it on then hose it down.

 

[Vikas]

I came across a 2000 MB E320. Unfortunately, it has cancer :-( He is still asking over blue book! Front rocker panel bottom corner is crumbling. Paint is bubbling at few other places too. I have not put the car on the lift. Is it worth even taking it to my mechanic?

 

[doitmyself]

Donald,

Seems like I follow you around BITOG, only to (attempt) to rain on your parade!

Here's my experience and opinion on rust converters. I desperately want to believe in them, but so far I am disappointed.

- Internet search will teach you that there are two basic types: phosphoric acid (Krud Kutter) and tannic acid.

- Google "rust converters" and study the various brands and they look

VERY

convincing.

- Google "rust converter research", and you come up with 3 studies (US ARMY, Brazil, Canadian/US.ongoing study) with stuff like this: Brazil...."The conversion of rusts formed in alternated immersion tests succeeded with a formula based on tannic and phosphoric acids as proven by spectroscopic analysis........In spite of this, no significant difference on the performance of converted and no-converted painted samples was verified which would justify the use of a rust converter."

I have tried the phosphoric type on equipment and buildings with mediocre results. I want to try the tannic acid type next, as the original Canadian study(now U.S) suggested this might be better.

In my opinion, the products like POR 15 work because you do both extensive treatment of the rust, then you ENCAPSULATE it. Face it, if you can completely keep moisture and oxygen away (paint, grease, wax, whatever), the rust should be subdued.

I wonder if the anecdotal results with products like OSPHO are due to the converter or the primer/paint afterwords?

Man, the marketing hype sure is convincing, though. I am still in denial, in spite of my real experiences.

Ironically, one product that seemed to work for me years ago was Rustoleum rusty metal primer, which is very old school, fish oil based technology. Hmmmmmm.

 

[Donald]

I emailed the manufacturer of KK. It seems their explanation needs to be a little more explanatory. If you put on the KK and let it dry it will form some whitish crystals that protect the surface for awhile (12 months). You might do that if you plan on getting back to it and painting it latter. If you want to paint it now, you use the KK and wipe it with a damp rag after 15 minutes. If it got to dry, then reapply KK, wait 15 minutes and then wipe it with a clean cloth.

In my case the rusty area is under the seat (seat is off now) and I could protect it by painting it or with Amsoil HD MP. Your hands or clothes do not come into contact with that surface so it could stay waxy like the Amsoil HD MP would leave it.

I think the trick here is to not let 20 years worth of wet/oily wood chips/dust accumulate. I just got it and am trying to "spruce" it up a little. I have a new seat in a box ready to go.

I could believe that KK could come up with an overhyped product, but it seems less likely that Loctite (Extend product) would do that.

doitmyself - will I see you over on the skidsteer forum also??

 

[Fitz98]

I have had good success with Ospho.
The best case is where you can sandblast the part(s) first and the spray Ospho on to neutralize any minor remaining rust.
I restored a set of seriously rusted iron spoked wagon wheels this way.
I have also used Ospho on my truck frame and suspension and to neutralize some light surface rust on the bottom of my doors. (truck came from 10 years in Connecticut).
I find that brushing it on is not as effective as a good even soaking coat applied with a spray bottle.
Remove all the big heavy rust first, with hammer, flat screwdriver, scraper, then wire brush the remaining. Get as far down to light rust as you can, since the Ospho seems to work better on the surface of the rusted areas. I don't think it penetrates through layers of rust well. After that, spray on the oshpho. Let sit 24 hours, then wire brush the white powder off and either prime and paint, or repeat Ospho if necessary. I did not rinse, just wiped with a rag, wirebrushed and primed and painted.
I have tried many rust treatments...I hate rust, but while I am not sure if there is a cure all solution, Oshpo is the best I have come across.
It's about 25.00 a gallon and goes a long way and is a relatively simple process. I would say that as far as risk/vs reward for the investment, that Oshpo would be worth a shot.

 

[Fitz98]

Also wanted to add that OSPHO causes iron oxide (rust) to chemical change to iron phosphate - an
inert, hard substance that turns the metal black.
It is the phosporos type.
If you don't need a lot, I think it's about 15.00 a quart. Available at some auto parts stores and I think at Ace.

 

[Donald]

So KK and Naval Jelly and OSPHO are all the same phosporos acid? Is there a reason to think one might be better than another?

Is the sulfuric acid better in an JCI battery than a Exide?

The rust treatment on the Bobcat seat pan, was also somewhat of a practice for the rust at the bottom of my Jeep doors where the metal is folded back up. I will try POR there.

 

[Fitz98]

Here is a link to a before and after picture using the Ospho on my truck suspension. The black you see in the after picture is the rust converted after 1 spray application of Ospho. The next logical step would have been to prime and paint, but I didn't since it's just suspension, it did stop the severe rusting process though.
Regarding one being better than the other, I don't know. When I find something that works, I stick with it, but maybe the percentage of chemicals are different from one to another, like household chlorine bleach, vs. a pool chlorine.

www.hometheaterlifestyles.com/AfterOsphoapp.html

www.hometheaterlifestyles.com/RustPretreatment.html

 

[Fitz98]

Also I used the Ospho on the hem of my doors too.
It is a viscous liquid, so I scraped all the heavy rust off first (screwdrivers, angled picks, wire brush) and then applied the Ospho and let it run like water into all the crevaces and it actually flowed in behind to get the inside of the hem too. (Don't get it on paint that you want to preserve..it will melt it). In this case I used a small chip brush to maintain control of contact to painted surfaces. Just get plenty of liquid in as many surfaces as possible, the rust behind what you can see is still active, unless you treat it.
Then I primed it 24 hours later after a light wire brushing and dry wipe with a cloth and haven't had any rust come back since April. I will get around to a top coat of paint soon to protect the primer and seal it completely.

 

[Donald]

Are you rinsing the OSPHO? Wiping it clean with damp rag?

 

[Fitz98]

Not rinsing. Applying as much Oshpo to saturate the part, then let sit 24 hours. If there was any heavy drips, they might still be moist after 24 hours, so I just wipe those with a rag. No water rinse.

 

[Donald]

Here is a pictures of the area where I used KK waited 10-15 minutes, wiped with wet cloth, wiped with dry cloth, and wet & dry again.

 

[Donald]

To finish up, first picture is with Rustoleum primer (it says it self etches also) and some Amsoil HD MP sprayed towards the back mostly. Second picture is the finished product, new seat off EBAY.





I think the secret here is to not let a bunch of oily/wet wood chips and sawdust stay on the seat pan for 23 years.

 

[ltslimjim]

Nice fix Donald.