In the Court-Hampton Painting video below we teach you how to mix a batch of Sheetrock 90, 45, or 20.
At over 19000 Youtube views this has been a popular video about mixing Sheetrock 90 for painters and DIY enthusiasts!
How to mix sheetrock 20, 45, 90? Toronto painters Court-Hampton Painting show you how!
You will want to use a gypsum based compound such as sheetrock on your first coat of plastering patches or entire rooms. You can finish with a final coat of drywall compound if you wish. Sheetrock is stronger than pre-mixed compound and sets in 20 minutes, 45 minutes, or 90 minutes, hence the different names on the bags.
The mixing ratio is 3 parts powder to one part water. Only make enough Sheetrock to use in the time allotted. Hardening action cannot be prevented or delayed by dilution with water. In the video above we add water to powder to show visually the water to powder ratio. You can reverse it and add powder to water once you are comfortable with the ratios if you wish.
It is handy to have a wet rag available to wipe your putty knives and clean your tools if you are mixing multiple small batches of Sheetrock 90 as it can dry quickly on tools and is easier to wipe off wet. It is always better when plastering to apply thin coats and blade off excess Sheetrock on the wall or ceiling being plastered to avoid excessive sanding. Two to three coats of plastering is usually required so keep it thin! When sanding start on the outer perimeter of the patch and then gently sand to the middle. Wear a mask and vacuum up all dust.
Sheetrock 90 setting type compound is sold by CGC and they can provide Material Safety Data and Technical Data sheets.
Sheetrock 90, 45, 20, is humidity resistant and is great when painting or finishing bathrooms and kitchens.
It is also has more strength than premixed compounds. In the picture above we used mesh fibreglass tape and Sheetrock 90 to plaster an old doorway so the joints won’t separate.
If you need drywall patching or plastering on a plaster and lath home call Court-Hampton Painting Inc.