Re: Garage Drywall
It is noteworthy to mention that old, unfinished drywall is extremely dry, dirty, and sun faded. This causes several problems when trying to now finish it, 24 years after the fact.
1 - Being old and dry, as you apply wet compound over joints, nails, and other repair areas, the surface of the paper can bubble up and/or feather (delaminate ). This isn't as big a deal as it sounds, when you're ready and expecting it. Basically, get your first coat of compound on there and let it dry. Bubbles and feathering can be carefully sc****d, removed, and filled with more compound. Applying texture once you're done with the finish work will help to hide any irregularities or roughness.
2 - Being discolored with dirt and faded causes two problems, the first is that drywall compound won't stick to an obviously dusty surface. Vacuuming the walls and ceilings will remove the dust. When you're done with the taping and finishing, either vacuum or sweep the walls down again ready for paint. The second problem is the faded surface is that it will bleed through your paint, causing blotchiness or worse. Prime the walls with two coats of Zinnser Bullseye 123 (blue label ) primer. If you notice any bleed through at this point, either apply another coat of primer or switch to the red label Zinnser. Topcoat with whatever paint and color you like. Stay with better quality brand names and "professional" product lines. Do not use the cheapest paint you can find. Do not use "contractor" grade paints.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!