Remote power - refinishing a bridge

[huntdupl]

Opinions and solutions for minimally invasive techniques on refinishing a bridge.

There's a concrete bridge with metal handrails right outside my house, it was built by the WPA and somewhat Art Decoesque. The bridge has the original coat, no flaming or chipping just dirt and mold which warrants a cleaning. The metal handrails in similar condition, minimal surface rust, nothing a wire brush couldn't fix.

Lots a activity in this public area and a refresh in order. I'm looking at taking collections for paint and supplies. The bridge spans a creek and in the light of doing this without proper permitting etc. I want to leave little to no reason for anyone to complain. I.E. minimal noise and dust collection.

The biggest challenge is finding a way to clean the concrete from dirt and mold.
Spitballing ideas
-gas pressure washer - cons- loud and is siphoning water from the creek would be the only source
-wire brush with dc - cons- power source and big investment for a charity project - Makita cordless backpack vac and cordless grinder with brush
-generator with ct midi - cons - loud and how much power needed?

I don't want anyone asking "is that lead paint" or "is that going to harm the fish"? What's the safest quickest was to prep the concrete and how important is it with Behr masonry paint. Can I just wipe with a rag and TSP without scrubbing? Anything will look better than how it looks now. And any advice is greatly appreciated. Thanks in advance

 

[Gregor]

in the light of doing this without proper permitting etc.

My suggestion: Get permission. Just to CYA in case someone acts up.

 

[Klemm]

why go it alone ? -when you can enlist help from the NATIONAL TRUST FOR HISTORIC PRESERVATIONhttps://savingplaces.org/contact#.WZ8BFCiGO70 - and through them connect with other like-minded preservationists.

I would be especially thoughtful with any coatings, paint and the like. If you end up with something less than optimal, the pain of re-mediating it afterwards can really be a challenge in every respect.

You didn't say but is this bridge private property or public?
Sounds neat - send some pictures
Hans

 

[Pnw painter]

Pictures would be helpful to get an idea of the scale of the project. Who owns the land the bridge sits on? If it's a gov agency then I wouldn't proceed until you have permission. As the saying goes "no good deed goes unpunished" and I'd hate for you to get in trouble when you're just trying to help.

Sherwin Williams, PPG and other industrial coating mfg's provide coating system recommendations on their websites or at their industrial stores. When it comes to rust, burying it in the maximum mill thickness recommended by the products data sheet will help the rust from reappearing sooner.

Sent from my iPhone using Tapatalk

 

[Bob D.]

If you got approval from the owner (individual or local government) then you could go after donations
of materials and maybe tools.

You might get a local rental company do donate use of a compressor or generator for a couple days.
A local paint store or a big box store might be willing to give you some paint or painting supplies.

You might try some of the industrial coatings companies like Enecon to name only one of many.
Enecon (and others) makes coatings designed for concrete repair and protection in harsh environments.
Some of their product have a shelf life that many facilities can use after the expiration date and they
become trash. Those products are probably still 100% serviceable for a project like yours and rather
than having to dispose of them as controlled waste they might be willing to donate to a worthy cause.
You wouldn't want to buy them as they are very expensive (hundreds od dollars per kit), but if free
they might be worth your time.

 

[nclemmons]

Makita or Dewalt make excellent angle grinders that can be fitted with a wire brush - either straight or cupped.  They work really well if you want to go that route -

 

[Cheese]

Most invasive...sand blasting
From there on out here are some alternatives, in the order of potential destructiveness,  copper  or lead BB blasting, walnut shell blasting, plastic microsphere blasting, soda blasting and vapor honing.

Something in there will probably work, it depends upon the equipment available and the tenderness of the structure.