Wednesday, March 10, 2021

Yesterday's experiment WORKED: converted the rust on the inside of the chassis truck frame

 So I got a gallon of "Kleanstrip" Metal Prep which is the cheapest deal for local phosphoric acid - it is 50% mix - and then I got a gallon pump sprayer.

I found an off-road site that was out of sight - and quick went Hog Wild - the Kleanstrip is considered environmental friendly since it's just 2.14 pH compared to vinegar of 2.44 (as per my memory).

https://www.toyota-4runner.org/3rd-gen-t4rs/195016-frame-rust-get-klean-strip-prep-etch-home-depot.html

Here is what someone else reports.

 avoiding parking it in a heated garage when it has any salt/slush on it.

Right our garage is NOT heated but it is insulated - so before the car was kept outside.

 Ferric phosphate is the older name. Now it is called iron(III)phosphate.

Right - so they recommend Fluid Film which is Paraffin Wax. I can get that locally at NAPA.

I did use rp-432 last year and it seemed to work. I just have salt in the center of the cross support - that did not come off in the car wash.

But otherwise the rp-432 Cosmoline Paraffin Wax enabled the salt to wash off.

So instead of mail ordering the Cosmoline - I'll just get the Fluid Film locally.

But first I will do several layers of the Rust Converter Rustoleum paint - because the ONLY reason it rusted on the bottom of the frame is that is where the car LIFT was on the frame - and so scraped the paint off the frame.

But someone said, as I posted - to NOT use Epoxy paint as that does not breath. 

 Rust needs water and oxygen. The epoxy will seal these things out, but rust in pits is porous and will contain some water and some oxygen. If you entrap these they will start rust going under the epoxy and more than likely lead to pinholes which will then lead to more rusting. You really need to nuetralize or remove the rust to fully prevent any issues.

Someone else said they prefer the Epoxy paint to keep the moisture OUT.

 Even if you have rust pits as long as they don't go threw to the other side and you have epoxy over it its sealed from air and water it cant rust.

Even the pits are going to be saturated in epoxy cmon guys once its sealed its sealed. no water no air no rust.

So instead I'll use several layers of Rust Converter paint and then the Fluid Film.

  Actually, the white stuff and iron phosphate is a pretty good surface to paint on as long as the heavy or loose scale is removed and a good primer/sealer is used. good luck with your project!

I actually bought some epoxy paint - so maybe I should return it then. I have the receipt in the car.

Main Product Image 1

So I just need to do some more rust conversion. I will use the GEL spray today - as it doesn't drip so easily. Yesterday since I was driving - then I could use the Kleanstrip liquid phosphoric acid.

The liquid seems to react better on the metal. 

So it is 53% phosphoric acid.

What is the gel percentage?

https://www.rustoleum.com/MSDS/ENGLISH/300112.pdf

Yes says 25% to 50% - quite the range!!

https://www.toyota-4runner.org/3rd-gen-t4rs/143309-simple-frame-rust-repair-prevention-2.html 

So that link they are using the Eastwood Internal Frame coating.

Yes I will do that next - I have it ordered.

The treatment of metal surfaces with phosphoric acid or phosphate salts to provide a coating of insoluble metal phosphate crystals is referred to as phosphating

So that's what I just did yesterday and the day before. I will do more today.

So, I called the Rustoleum company and spoke with one of their specialists.  They in no uncertain terms told me that you definitely should not cover any rust with epoxy primers.  Furthermore, you should not cover their rust converter with an epoxy primer.  I asked if that meant that I needed to sand off all the converter.  I was informed that would not be necessary.  Rustoleum makes a product (a shock) called clean metal primer.  It could be applied over the converter and either urethane primer or base color could be sprayed on top of the clean metal primer.

 

 Wow - so that's the "Clean Metal Primer"? Fascinating!

I'm gonna try that stuff out.

https://www.classiczcars.com/forums/topic/61223-i-did-a-foolish-thing-epoxy-primer-and-rust-converter/ 

 Eastwood rust converter or Ospho or any of the other products are just phosphoric acid, it converts iron oxide into iron phosphate. You have to remove as much of the rust as possible before applying it because it can convert the top layer and turn it black (iron phosphate) and leave rust underneath. You apply it and must keep it wet to keep it working, if it dries you will end up with the white powder and no paint or primer will ever stick to it, you will have to sand it off.  You need to wash the converter off while it is still wet with water but even then I have still ended up with the white powder.  I don't use phosphoric acid any more because it is such a pain in the arse.

Ah so - is this what just happened to me? We shall see!!

I'll keep an eye on it.

you really don't want the gel type to dry. It becomes this hard crust that can be very difficult to remove.

OK I won't use the "Gel" spray from Rustoleum anymore.

This is fascinating to be sure.

I'll check the paint tomorrow to see if it stays on my treatment. I didn't check for any powder - it is hard to reach this spot.

Be careful if you use the phosphoric acid or any other type of rust converter under your paint.
Unless you wash it all off and dry it thoroughly it can come back to haunt you. See my post "Blister in Paint" on the ********** site if you want to see the results.
I had one small (1/2") blister that came up when I buffed. Turned out to be caused by the rust converter under the epoxy and resulted in having to strip down to metal and repaint.

 

I had the same problem using the Dupont green phosphoric acid "neutralizer". The directions, which have now been changed, said to rinse off the panel with water until the water "sheets" off of it. I can't remember how it said to dry it off, but the bare metal had a slight brown haze on it. :twisted: I followed the directions exactly, and then primed and painted.

https://www.yotatech.com/forums/f116/best-rust-neutralizer-opinions-welcome-101607/ 

You spray it on the rust and let it dry it turns silver and then you paint over it.

Yeah pretty sure I had SILVER and not white...

  I read somewhere to use a scrubby to get rid of the white powery stuff left from the Phosphoric acid berore you paint over it.

OK fine - a "scrubby" - I need to get some of these.

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