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What method to remove paint from galv steel tower?

What method to remove paint from galv steel tower?

What method to remove paint from galv steel tower?

(OP)
My task is to remove lead paint from a 60' galvanized steel radio tower.  The old paint is in bad shape and creating a health hazard (lead paint dust in nearby building hvac ducts).  100% removal desired.

What methods are available/recommended for removal of the paint?  Being a tower, there would be lots of corners, angles, etc.

Chemical stripping:  Could be less damaging to galvanized coating so recoating would not be required.  Repainting is not a requirement (FAA, etc).

Sand Blasting:  Would probably damage the galvanized coating which would require recoating and future maintenance of coating.  Greater environmental risk due to creating lead dust.  

Please help me to understand what the typical method of paint removal is in this scenario.  Thank you!

RE: What method to remove paint from galv steel tower?

If I were in your place I would check with a lead abatement company as you have to keep the lead off workers and the ground. It is not going to be cheap.
 
Here is a short discussion of the federal laws. You will also have to check with your state agencies.   

http://www.ehow.com/about_5305942_lead-paint-removal-laws.html

Paint stripping products.

http://www.paintremoval.com/leadpaintremoval.htm

http://www.leadoutpaintstripper.com/

Over coating or encapsulating lead paint, one of many.

http://www.nansulate.com/nansulate_LDX.htm?_kk=paint%20over%
20lead%20paint&_kt=59ece081-46e6-4e35-8a33-8c5bd6959481&gcli
d=CPCSlbbnuKYCFQrt7QodCzRbGg

http://www.paintremover.com/paint-removers-lead-paint-encapsulation.html?gclid=COKH_u3nuKYCFYnt7Qod9iU9Hw

One of many contractors to remove lead paint.

http://www.dhgriffin.com/environmental/lead-abatement-removal.asp
 

RE: What method to remove paint from galv steel tower?

Two issues:
1. Removing the paint without damaging the galvanizing.
I have had good success with blasting painted galvanized (epoxy coated) with corn cob media http://www.kramerindustriesonline.com/blasting-media/corn-cob.htm

2. Lead abatement regulations
OSHA and the states have some very strong regulations, including blood lead level monitoring of employees, specific hygiene requirements on-site and required training and certification. In my opinion it would be best to hire a certified contractor.

Richard www.6sproductivitycom.com  

RE: What method to remove paint from galv steel tower?

(OP)
Thanks for the responses.  I'll look into soft blasting media and chemical stripping.  Of course we'll be following all the lead laws, monitoring, and safe practices.  Agree we need a specialized contractor, so will be putting those requirements into bid documents.   

RE: What method to remove paint from galv steel tower?

So this is a galvanized steel tower which was painted?  That's the reason the paint is peeling!  Galvanizing requires a light sandblast before coating...industry practice.

Full removal would include:

Full containment of structure, abrasive blast, apply zinc rich coating followed by epoxy or a variety of topcoat options.

If you try and cut corners when coating galvanizing, you will be sorry.

RE: What method to remove paint from galv steel tower?

You may want to look at enshrouding the structure and using corn/walnut shell blasting or using 'dry-ice' to minimise the damage to the zinc coating.

You may also want to look into encapsulating the existing lead paint (this could be an environmental issue several years down the road).

You may also want to coat the possibly damaged zinc coating (after blasting) with an epoxy coating system; there are a couple of these that work with galvanised coatings.

As noted, the failure of the leaded coating was likely due to a zinc saponification that causes a chemical 'zinc soap' interface that doesn't bond well.

Dik

RE: What method to remove paint from galv steel tower?

You might try blasting with dry ice.

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