[florin]

I have to pressure wash some 5000sq of exterior metal that has been painted 6-7 years ago before I can repaint it.

I rented a 3500 psi power wash machine and I get as close as 1 inch to the metal but it still doesn't get all the dirt and crap off. Only cleans about 80%.

I get all wet and my eyes dirty when I finish only a few feet. I can't even use protection glasses cuz they get dirty and foggy immediately.

Any suggestions?

 

[tsunamicontract]

better chemicals.

 

[bikerboy]

Is it stained? Have you rubbed/scrubbed after pressure washing to see if anything else comes off?

 

[MAK-Deco]

My thought too are you using any chemicals?

 

[seversonspainting]

Your best bet is to find some heavy duty chemical and spray the building down and let it stand for 20 to 30mins. Then come back and try pressure washing it again.

 

[tsunamicontract]

first, identify the dirt and grime on the substrate. Then you can figure out the best cleaner. You should have to be getting so close with your wand, that will take forever to clean that much metal. If you are cleaning it with just water and there is some kind of grease or oil on it, the water will not take it off no matter how close you get.

 

[MAK-Deco]

If you are cleaning it with just water and there is some kind of grease or oil on it, the water will not take it off no matter how close you get.

That what my thought was as well.

 

[Ken S.]

1. Do chemical application at an above/side angle to protect yourself, with wind to your back/side(keep spray and chemicals away from coming back at you).

2. Use sodium hydroxide based cleaners, but with caution(use safety protective gear. Apply chemical cleaner, let dwell for 3-5 minutes, and pre-scrub before power cleaning off.

3. Try a rotating "Zero" degree tip when cleaning.

4. Pump should be putting out 4.5 + gpm's for effective cleaning.

 

[tsunamicontract]

MAK we just must be on the same wavelength, huh?

 

[Wolverine]

I notice that no one has asked... What kind of metal? What is this metal structure? This could make a big difference...

 

[bikerboy]

I notice that no one has asked... What kind of metal? What is this metal structure? This could make a big difference...

Ugh....metal with paint on it. Yeah, that's it.

 

[daren]

It might just look ugly after washing. If it looked good then you don't need to paint it. Your goal is to remove the dirt not make it look new.

 

[CApainter]

Use a face shield.