How To Touch Up Galvanized Steel Roof Panel Scratches
Below are steps to prepare the metal before using touch up paint.
How to touch up galvanized steel roof panel scratches. Touch up and repair with zinc spray metallizing zinc spray metallizing is done by melting zinc powder or zinc wire in a flame or electric arc and projecting the molten zinc droplets by air or gas onto the surface to be coated. Rub a gentle scrubbing cleanser onto rust spots on metal roofing using a clean cloth. Place a piece of scotch tape 610 over the touched up scratches and rub your thumb across this a dozen or so times with firm pressure. Dab a small paintbrush into metal touch up paint and then cover the scratched area with the paint.
While these paint coatings are durable improper handling and installation can mar and damage the finish. Place the first screw about 7 inches from the bottom and each subsequent screw about 18 to 24 inches apart along the vertical run. Clean the scratched portion of the roof with the mineral spirits and then rinse with clear water and allow it to dry. Galvanized steel on the other hand cannot be painted with an oil based or aluminum based paint.
Let the paint dry for at least 48 hours. Touch up paint can cover unwanted scratches chips abrasion marks or other lightly damaged areas on the panel to present a consistent finish and appearance. The roof panels are installed similar to the wall panels in layout. The washer under the screw head should seal to the surface of the panel without bulging or shifting.
All painted metal panels have a factory applied baked on finish. Install the roofing screws vertically along each rib in the panel. Cut the first rib off leaving of rib on the first roof sheet of roof steel. Use a paint pen or 1 4 artist brush only the narrow edge of the paintbrush should contact the scratch or blemish lightly sand or feather with 400 grit sandpaper for edges of deep scratches.
Scratches can easily be fixed with a paint or touch up pen designed to match the color of the roof. Secure the screws but do not overtighten. Galvanized metal requires either a zinc dust type paint or a latex paint. My house was built circa 1880 and still has its original terne metal roof which consists of individual metal shingles with an embossed decorative pattern.
Using screws fasten roof at top and bottom of the sheet in the flat next to each rib. The zinc used is nominally 99 5 pure or better. Lay down the first roof steel panel squaring it with the mason line.