TheSamba.com :: View topic

Sat Jun 12, 2010 5:17 pm

ospho and jasco prep

I have asked a few times if anyone knew the difference, if any, between the two, as neither of their websites or instructions offer any real info.

It appears that jasco product WAS the same thing. I went to my tru-value store and they've started selling the OSPHO on the same shelf as they used to sell (and still have a couple of old dusty bottles) jasco.

SO I bought some, smells, looks and feels like the same thing with the same warnings and instructions. I'll be poking around the forum for opinions on proper volkswagen usage.

So, that's that.

Sun Jun 13, 2010 3:44 am

Post back if you find out anything.

Sun Jun 13, 2010 10:37 am

well I used it yesterday.. Let it "dry" overnight.
Now the panel is covered with some sort of "gross" byproduct. Don't know what I'll do about that.

BUT.. I did leave a couple spots of rust (rock ding marks) and it managed to dissolve all but 1 of them. The one it didn't dissolve turned black. So I hit it with some sand paper to reveal the rust powder underneath.

It does nothing to rust it doesn't dissolve. That rust spot was maybe .00005" thick. Like 3 swipes of a piece of 400 grit and it was gone... but still had orange under it.

It immediately took off the flash rust like my etch rinse does... but I'm pretty sure its not "etched" now, and my etch probably won't work on this coating.
I think I'm going to try it, as I'm going to be doing body work on the panel over my epoxy, I'll have time to see how it sticks.

Sun Jun 13, 2010 1:55 pm

not at all happy with ospho results this morning.

Think it took my flash rust, dissolved it, then solidified it into kind of sticky lumps.

I read in a hot rod forum that they recommended "rinsing" with ospho, wiping off THEN doing a real application.

I sanded and am going again, as it does have quite the reputation for working well.

Mon Feb 03, 2014 8:47 pm

i have some issues with some ospho i used on my bus frame rails that i hope someone can resolve.

i used a wire wheel on a grinder and removed all the rust i could; cleaned with solvent to remove any grease. etc., then applyed the ospho.

looked like there was some rust that did not convert the next day so i applied a second coat.

let this dry for a few days and cleaned off the powder that was left after the conversion. then applied paint

the paint i used is now bubbling up in alot of areas; you can wipe your finger on the bubbles and there is a wet acid residue where it bubbled.

any idea what may have caused this? did i not let the ospho dry long enough? any help appreciated.

Tue Feb 04, 2014 5:00 pm

I use picklex 20 on all my stuff

it looks like this if you apply it to a clean surface, let it soak, then wipe it dry

if you just slather it on and let it dry, it looks like a chalky mess, with some rust thrown in.
which cleans up fine if you re-apply and wipe it down dry.

I also wipe it down before paint or powder coat to remove any loose powdery leftovers.

Are you wiping it down before painting?

Tue Feb 04, 2014 6:21 pm

Ospho is best applied in a light coat then wiped dry. The little amount left behind keeps the metal from flash rusting. I like to use Gibbs Oil to keep the metal from flashing.

Tue Feb 04, 2014 6:44 pm

yes i wiped it down with some solvent before painting. i wire wheeled the loose powder and residue before wiping down.

i believe i may have applyed it too heavily, with too many applications.

Thu Feb 06, 2014 5:56 am

I've seen that same white powder before if I left too much Ospho on the metal and let it dry. What I have started doing is buying just plain phosphoric acid and soaking really rusty parts in it until all the rust is gone...Then I wash the parts thoroughly and dry them and immediately paint them. I still use Ospho on the body and frame, but I try to get the worst of the rust off first. I let the Ospho sit on the metal for a few hours and then rinse it off. The paint seems to stick better that way.

Fri Feb 21, 2014 7:53 am

I posted above that i was having issues with paint bubbling after it was applyed over top of some ospho treated areas on my bus frame rails.

I applied some ospho to a different area and tried a different application method. Sprayed it on , let it sit for 10-15 minutes, then wiped off the excess; i did not wiped the area dry, just got the majority of what was still wet off. I did 2 applications like this.

This method worked much better; the area dried well, with only slight white powder being left behind after drying.

I believe most of my paint adhesion problem was that i applied too much, did'nt wipe off the excess before it became sticky.

Tue Feb 25, 2014 9:12 pm

I use Ospho all the time with no problems ever. I spray it on lightly, scrub in with a maroon scitchbrite, then after 30 min or so I wipe off the excess. I then go over it again before paint with another maroon scothbrite to knock the crust off. But I also sand blast my cars first. I only use Ospho if they are going sit bare for a while. If i can, I put epoxy on asap (not POR15).