How to removed crusty ospho?

[strantor]

I'm trying to save my mower deck, it had a poor powder coating I didn't realize, has been aggressively rusting. I needle gunned, wire-wheeled, and applied ospho, let it set overnight and now I have crusty bubbly black patches everywhere. I don't want to paint over that. I tried blasting it off with my pressure washer, partially effective, but not really. Is there some other face & respiratory melting hazmat I can apply to dissolve the black crust? Will applying more ospho do it?

 

[jaxs]

:laughing: The difficulty you are having in removing it is testament to how well it is adheared. The stuff is a rust convertor and adheasion promoter,not a surface smoother. Count your blessings and give it a couple coats of good paint.

 

[strantor]

:laughing: The difficulty you are having in removing it is testament to how well it is adheared. The stuff is a rust convertor and adheasion promoter,not a surface smoother. Count your blessings and give it a couple coats of good paint.

If you saw it you would sing a different tune. Its looks like burnt cauliflower is growing on it in some places, 1/4" thick.

 

[strantor]

I found a solution. Spray more ospho, let sit 10-15 min, pressure wash, repeat. I don't even let it dry before spraying ospho again. It seems the ospho displaces water. Most of the gross areas were gone after the 2nd or 3rd round. A few stubbing spots left, going to do one more round (#5 or 6, lost count) and call it good.

 

[3Ts]

I'm trying to save my mower deck, it had a poor powder coating I didn't realize, has been aggressively rusting. I needle gunned, wire-wheeled, and applied ospho, let it set overnight and now I have crusty bubbly black patches everywhere. I don't want to paint over that. I tried blasting it off with my pressure washer, partially effective, but not really. Is there some other face & respiratory melting hazmat I can apply to dissolve the black crust? Will applying more ospho do it?

When I have it like that, I'll get some sandpaper out to smooth it up. If it's not black, gray, or bare metal after sanding it, another coat of ospho.