When blasting isn't enough...

[idrivejunk]

Media blasting is the "end game" when it comes to rust removal, right? Of course it is. Or is it?

A newer coworker did a lovely gentle blast job on my current project's cab. The roof had a lot of broken paint, weathered and scratched, where rust had occurred.

The freshly blasted roof still had too much rust present after blasting Wednesday but the panel was not warped by blasting. First thing I noticed when I began sanding for epoxy primer prep yesterday. It is being primed today. So here is what I did, with little hesitation.

I used EvapoRust and did two applications in an hour and twenty minutes. Watching the rust drip off. Good scary looking pictures! But as can be seen, the result is good and skipping this acid step would have been a mistake, IMHO.

Just sharing these visuals in case some of you have never gone down this road. I was well pleased with the results.

[kb426]

I'll remember that. I had been tempted to try that but wondered if it would dry out before doing anything.

[idrivejunk]

You gotta gotta keep it wet! Misting with water works, and by application I meant standing there with a cup and scrap of scuff pad for dipping and scrubbing and keeping it wet. On the Merc truck roof I laid plastic over it wet, overnight.

It is less agressive than ospho and easier to clean up in my opinion. If it weren't effective though, I wouldn't be showing the results.

[enjenjo]

Back in 2003 I had the roof on my 65 Buick painted with silver metalflake. The roof had surface rust on it and I was selling Rust Bullet paint at the time. So I had the body shop scuff it and paint it with two coats of Rust Bullet and then the metalflake paint and clearcoat. My grandson has the car now and the roof still looks as good as it did back then.

I would still be selling Rust Bullet but the company changed hands and fired all the dealers. It is still a very good product.

[chimp koose]

I have used feed molasses and water in a 10:1 mix with excellent results . Leave the part submerged in the solution for about 2 weeks and it comes out shiny. I made a box to put a plastic sheet into and did a trunk lid and a door for my T coupe . I was kind of thinking about submerging the whole cab at some time .

[idrivejunk]

I wasn't pushing a product. Blasting just isn't magic, thats all.

[chimp koose]

The molasses mix will not remove paint . Not good on cast parts either .

[idrivejunk]

Hmm. Never had the occasion to consider acid for cast stuff. I can imagine why thats probably not good, can't flush away the product thoroughly enough.

As for painting over light rust... I use Eastwood rust encapsulator quite a bit, stuffing it into hidden areas and flooding seams that just ain't gonna have the rust removed. But I have seen what it looks like sprayed on an S-10 roof then being outdoors for a decade. Still black, and a tough coating. I am not in the paint over painted over rust camp but our painter may be. In a suitable area of lightish pitting and rust under the car, yeah hey if you need to put color there an encapsulating product in between makes that a lesser sin.

Leave-on, paintable rust converter products... I have no trust in at all, unlike encapsulating products. Theres a context where all other type products may apply, but not that one. Such as Rust-Mort or Eastwood rust converter. I think it is a mistake to use those anywhere. They just form a crust but encapsulators flow in and use the texture to adhere.

At work I have pretty much used three acid products and have made distinct observations of each that help me choose which jug to reach for.

Picklex20 is a one step metal prep. Wipe on then off. Very light rust goes right away and of course a residue is left but I consider it benign per instructions. What Picklex does and I assume it is vinegar based (a pickling solution?) is aside from dissolving very light rust, it really brightens the metal. My best looking fab pix were when I applied it before the metal sits bare for awhile. The residue can inhibit surface rust for months.

The Evaporust is next, it will do heavy rust dissolving and even work through bad paint eventually. The first post states that what I did took an hour and a half. Thats not a bad work time for as much rust that dripped off that roof. It is gentler than ospho but not by a huge margin, and the residue is a whole lot easier to deal with. Does not mark up the concrete anywhere near as bad. I have used up a gallon finally and in doing so, it has become my favorite. A nice balance of ease of cleanup and effectiveness. If you get a hole in your glove, no big deal keep going.

Oshpo is the big gun, to me. Horrible mess and so nasty but if you do the time, you'll get the rust off. More, faster than EvapoRust. Best for large heavily pitted areas but avoid getting it on stuff. On the cab roof above, I didn't want to use it because the residue is tougher to get rid of. I was worried the Evapo would not be aggressive enough especially at the bottom of the jug but it satisfied me and minimal time was spent.

And now the cab is in epoxy on schedule. So there ^^^ is a lighthearted review of products I have experience with. A range of needs merits a range of products to choose from, IMHO. Speed needed and severity required are the deciders. Slow, mild processes like the molasses soak are as valid as any approach but in my job world, time is a factor that cannot be ignored.

[kb426]

Good info. I have used half of the products you mentioned. I will try to remember the differences.

[chimp koose]

Well said , molasses is not for the job shop. If you are pressed for time use something else . My builds seem to take 10 years or more so I have time to squeeze in the molasses wait time lol