Picklex-Rust Treatments

The other way to go are the rust convertor paints and the rust encapsulator paints that seal off the metal from moisture. Extend was the first I can remember, not the best reviews. Any comments on the paints and how they've worked over time? There seems to be pros and cons to whatever product you choose in the neverending battle against rust.

I have had good luck with Extend on two separate occaisions. Both are over tightly adhering rust (after wire brushing any loose stuff off). One is a test area that has not had a topcoat. There has been no rust showing through in three years of continuous outside exposure. The other has been topcoated with epoxy primer, urethane surfacer and urethane color. There has been no obvious rust problem in two years of continuous outside exposure. I have tried both the brush-on version and the rattle can spray. I wouldn't give 10 cents for the spray but the brush-on works well...it is much more heavily bodied and seems to react with the rust in a far superior fashion than the spray from the rattle can. The tech sheet is for Extend is available here.

Rod

I have started to see the problems of adhesion with top coats over Por-15. I have read others reports too. I have a rock guard that was coated about a year ago, no rust return. It was top coated 2 months ago and just bolted up. Instead of just scratching into the paint, the bolts pull the primer and top coat off in flakes exposing the por-15. It is an experiment since as soon as the machine is run, rocks and sand will begin scratching it back up anyway. Now they make a sealer for it to address the problem, but it came out later so the manufactuer is aware of the problem too. I was attracted to it because of its hardness, thought it would hold up longer in the dirt. Something to consider with this product, buying their sealer makes its cost higher than a rust convertor. And does the sealer make top coats stick? Also sun quickly fades it, which they disclose as ultraviolet sensitive. TC.

Here is what they say on the ospho site: Directions for use
For Application Questions Not Answered Here Call Factory Direct at: 216-771-1590 RUSTED METALS - OSPHO is a rust-inhibiting coating - NOT A PAINT You do not have to remove tight rust. Merely remove loose paint and rust scale, dirt, oil, grease and other accumulations with a wire brush - apply a coat of OSPHO as it comes in the container - let dry overnight, then apply whatever paint system you desire. When applied to rusted surfaces, OSPHO causes iron oxide (rust) to chemically change to iron phosphate - an inert, hard substance that turns the metal black. Where rust is exceedingly heavy, two coats of OSPHO may be necessary to thoroughly penetrate and blacken the surface to be painted. A dry, powdery, grayish-white surface usually develops; this is normal - brush off any loose powder before paint application. NEW METALS - For new ferrous or aluminum metals: remove dirt, grease, or oil; apply OSPHO, let dry overnight, then paint. Contains phosphoric acid, i thought that's how removers worked on rust.
Just from reading ospho posts on other sites some people remove it because it gets too thick of a coating. Found that a little confusing as i thought the conversion coating was what stopped the rust. My guess is you would have to judge how many coats were needed until it all was converted to black. I wonder what you find under the coating--clean metal or a thinner layer of the rust. If so, seems you need to reapply it to convert again. Like paint prep everything needs to be degreased.

Surprisingly Picklex claims to be a degreaser and not affected by oil and grease and one thin coat only. ( i found posts by folks who apply several coats ). As you said not recommended for heavy rust without removing as much as possible. Non toxic, Mainly aimed at the small shops who use dip tanks and don't want EPA disposal issues/costs. One of the major differances, its weldable and claims to increase weld strength. Both claim paint adhesion is enhanced. Interesting how many differant products and approaches there are. I didn't find anyone who has a regularly used machine or car who has used something 5 years ago and says it worked perfectly. Maybe its because its new technology or the new posts have bumped them off the boards. Cars certainly don't rust as quick as they did in the sixtes/seventies. I did find complaints about poor adhesion of top coats to the rust paints. Hopefully we;ll get more input, theres alot of ospho users on other forums here.

I agree on a clean painting surface as prefered to a convertor. From reading labels we are bucking the trend. I found the paint remover with the picture of a big airplane on it at Auto Zone. (had my chain stores mixed up--Advance has Mar hyde stripper) This one was made by Kleen strip and not a rust preventer and stripper just a stripper. It was called Aircraft stripper. So the search continues if its out there. The removal instructions called for water rinse or laquer thinner wipe off and then a convertor to prepare the metal for paint. The one they recommended was made by them and sat next to the stripper on the shelf.

Assuming it works, i can see the use of ospho on a surface you know you can't protect. For example a frame or a wheel be it car or tractor. If its going to go back in the field or down gravel roads the scratches and chips will happen and begin the rusting process again. If the convertor works it would save the work of blasting or wire brushing to get to clean metal. If it stopped rust return for the life of the paint. We know removal works when done right but does conversion last or just delay rust from returning???

The convertors have my curiousity. I can understand the mistrust. I will probably test a convertor on something like that, some odd corner you can't get at and see what it does. Got a truck tool box that would make a good test for it. After having tried the Por-15 rust paint I'm in favor of trying a convertor because of adhesion concern as posted above. I took that to bare metal and used rust remover and the por-15 as insurance for under braces i couldn't get at. It is a hard as a rock coating, but adhesion to it looks like a problem. Rod NH likes the extend paint with good results. Thats a totally different formula.

I think if you were to scrape it off you should see rust in the same state it was when brushed to tight rust, as it's suppose to stop rust by turning the top layer into a black coating. Sort of like rust preserved like wood is under varnish. If either of these work, you have rust stopped and trapped under your filler and paint.. I'd prefer clean metal too but sometimes it comes down to you have to blast to get it.