Rust converter

[mikes48]

I'd like to use a rust converter on the inside of my fenders etc.  Looking for some info as to what people are using and what works and doesn't work.  I just don't have much experience with these.  Thanks.

[Los_Control]

Assuming the truck is not coming apart, ospho is a pretty decent product.

Instructions for it, would be to use a wire brush & remove all lose flaky rust.

Apply ospho to all surface areas & let it dry for 24 hours.

Claims it will convert rust to a paintable primer that you can paint.

 

I have bought it in a squirt bottle or a jug .... I find it best to pour a little in a throw away container & a cheap paint brush & brush it on.

There will be some areas that you can not reach with a brush, a squirt bottle is good for the hard to get to corners.

 

There are name brands of rust converter ... I'm sure Eastwood has a product along with all the other big guys .... Ospho you pick up at Ace hardware or Home Depot.

The few forums I belong to, ospho seems to be the most popular.

 

Here is a photo of when you spray it ... It is thick, inconsistent, runny ... it really creates a mess .... brushing it on is much better.

 

 

There is some rust showing. I was playing with my pressure washer to see how easy it would be to clean up. It cleaned up & flash rust right away.

 

If you are removing the fenders or body panels, I would suggest hydrochloric acid, also known as muriatic acid  ..... This is what is used to clean swimming pools.

YOU DO NOT WANT TO USE THIS ON YOUR TRUCK!

 

It does work great, but the fumes will flash rust things on your truck like the choke cable, or your gauge bezels ... things you do not want to harm.

If you do it out in the back yard away from the garage so you do not flash rust your tools .... it is great.

 

 

 

Here is the same bed side after it was cleaned with muriatic acid, now I'm wiping on a mixture of phosphoric acid & water to preserve it.    3 different acids

 

1, muriatic acid is the toughest rust breaker in town. You should wear a gas mask when working with it.

2, Phosphoric is pretty good and does a great job removing rust. This bottle is food grade for cleaning restaurant equipment, More safe to use.

3, ospho ... The main active ingredient is phosphoric acid, but has more ingredients to create a converter.

 

Modern acids work great, You use the bad boys in the back yard. .... On your truck ospho is the mildest, but it actually works as it should & safe to apply on the vehicle.

I think in the last 4 years I have made just about every mistake I can using acids.

 

[mikes48]

Well that was certainly informative.. I may have to take a look at the ospho. I used chassis saver magnetic black when I did my 67 camaro. That worked great,but that was on a rotisserie. 

[Tooljunkie]

I use rust check brand rust convertor. In a spray can. I find it goes a long way.i buy 6 cans at a time. May be a canadian product though. 

[mikes48]

I ended up buying FDC rust converter ultra.  It had a lot of good reviews.  I did the inside of one of my rear fenders and it seemed to work well.  The true test will be time..

[kencombs]

I think it depends on what your goal is.  In my case, I removed almost all the visible rust with rust and paint stripping disks on a 4.5" grinder.  So I only needed the converter to deal will little bits in pits or sheet metal folds, like at fender reinforcements and door skins.  For that I used Ospho.   I've used Picklex 20 which is really good, but come at a premium cost!  

That was followed with a quick hit with 80 grit and epoxy primer.   In the door skin and fender lap areas the primer was literally poured in as I had the parts on a table so I could roll it around to get it into every nook and cranny.

 

I don't trust any rust converter to work if the rust hasn't been removed first to a great degree.  Sanding,  grinding, stripper disk, acid or something needs to get to the metal.  Because, the primer bonds to the converter, the converter supposedly bonds the converted outer layer of rust to the substrate.  And in all the tests I've done and seen online there is always red rust between the metal and the black converted layer.  If the rust de-bonds from the metal, the 'sandwich' will eventually fail, IMHO.

 

Just don't trust that.

[mikes48]

Kencombs,

I totally agree with you. I took my 67 camaro 100% apart and had it on the rotisserie and made sure there wasn't a spec of rust anywhere. This truck isn't that kind of build. Doing all the metal work to get rid of any rusted through areas, but not stripping it down. I have to admit  it's hard for me not to make it perfect. ? 

[greg g]

Well rust is steel that has been converted to an oxide with no structural strength,then what does the the converter convert it to. Does the oxidation stop when it's encapsulated?  What comprises the encapulation?

[Los_Control]

Just now, greg g said:

Does the oxidation stop when it's encapsulated?  What comprises the encapulation?

What I have read & been told, it kills the rust & stops it from getting worse while creating a paintable primer .... is this really true?

 

What gives me hope is this one truck here.

 

 

If you look at my avatar & see my truck as it was pulled out of a field .... We call it a Texas suntan .... paint is just burned off from the sun.

I tried everything I could to mechanically remove the rust .... including 32 grit paper on a 4.5" grinder ... all it does is polish the rust.

Acids while disgusting, was the only way for me to remove the rust at home.

 

This truck is also a Texas truck that had some good suntan going on. This paint was 7 or 8 years old .... He went to a car show & saw someone copied his paint scheme, so he re-painted it & has different wheels now. ...... He just used ospho on the surface rust 10 years ago.

 

I took this photo 2 years ago

 

 

This photo a few weeks ago  ... It is dirty & needs a bath, there is no rust coming back

 

 

These are not "that kind of build" I would not suggest it for something being restored. After 2 years on my truck .... 10 years on the other truck .... I'm fairly confident with it.

[kencombs]

4 hours ago, greg g said:

Well rust is steel that has been converted to an oxide with no structural strength,then what does the the converter convert it to. Does the oxidation stop when it's encapsulated?  What comprises the encapulation?

It gets converted to Iron Phosphate (FePo4).  So the rust (FeO2) becomes FePo4 due to the interaction and 'stealing a couple of O atoms from the converter.   A good coating of it seals the underlying steel preventing further rusting.   But, the original rust must not have any loose areas lest they break loose, crack and breech that seal.    Same thing the expensive moisture cured coatings do, except they are more durable.   I choose to use the Ospho which is partially phosphoric acid, which provides the Phosphate part if the formula and strengthen the sealing part with a liberal coat of epoxy primer.   Epoxy sticks to anything, and everything will stick to epoxy making a good choice both as a rust sealer and underlayment for filler primer.