-- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

topic 12485

Protection of punched areas of GALVANNEALED (A60) material

I'm a mechanical designer. At our company we manufacture pre-fabricated weather-proof metal buildings. My question is, after we punch holes in our galvannealed (A60) panels, we deburr the punched area with a small hand sander (180 grit). I am concerned that we are damaging the A60 coating, please comment.

Ronald E. Davidson
- Canton, Ohio

Cold Galvanizing Spray



You're not damaging it, Ronald, you're completely removing it from the punched areas. In benign environments that's not a big problem because the ganvanneal can sacrificially protect the exposed steel. But with the environment that a roof sees, and the probable retention of moisture under the fasteners, it's not a good situation. I would protect the exposed steel surfaces with cold galvanizing solution [linked by editor to product info], or somehow -- with lacquer, paint, mastic, or something.

Ted Mooney, Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2017     -    Privacy Policy
How Google uses data when you visit this site.