Posted by Stephen Fry on July 25, 2003 at 11:18:15:

In Reply to: Re: Removal of Zinc Metal Spray from steel bridge. posted by Gordon England on July 24, 2003 at 11:08:41:

: : We are having 'economic' dificulties in removing metal sprayed zinc from a steel bridge deck (30 years old).Currently we have to resort to locally disc grinding after a single pass with a motorised shot blast unit.

: : Is there some 'benign' chemical cleaner or etchant that might reduce the adhesion properties to the steel substrate, thereby making removal easier.
: : Thank you,
: : Steve Fry

: Hi Steve

: Why are you removing zinc coating and what is to happen to the stripped surface?

: Acid pickling or rust removing solutions should attack and degrade zinc coating. I remember using concentrated hydrochloric acid with antimony trioxide additions for analytically purposes, which was very effective and left steel substrate completely free of attack. These methods are usually dip processes conducted in controlled enviroments. I think in your environment chemical stripping will be a very messy process and may not be that effective. Also, there would be serious concerns with regard to health and safety and environmental issues.

: I think grit blasting would be the best option, particularly if you are planning to re-coat.

Thank you for your reply. We are already moving towards a grit /shot mix which helps. Open blasting is not an option as the adjacent traffic lanes are open ( we have approx 14000 sg meters to do). I am advised that as the % grit content increases there is far more wear on the equipment and understandably there are commercial considerations in moving to a more expendable option.
We are replacing the old Zinc metal spray with a Stirling Lloyd product called BR Eliminator which provides a waterproof membrane prior to the new re-surfacing.
Thanks again
Steve Fry

Follow Ups:

	Enter your search terms Submit search form
	Web www.gordonengland.co.uk

Post A Message!

© Copyright Gordon England