What's the Difference: Premixed all-purpose joint compound
Heavyweight, lightweight, and midweight types are readily available and can be used straight from the bucket
Most of us who do drywall work prefer premixed, all-purpose, drying-type compound because it’s readily available and can be used straight from the bucket. All-purpose compounds can be used for all phases of drywall finishing, including embedding tape, filling fastener holes, and repairing minor wall damage.
This type of joint compound is available in three weights. They each cost about $15 per 5-gal. pail, but each performs differently on the wall.
Most manufacturers don’t label their compound products with the term heavyweight. That’s bad marketing. Unless noted otherwise, it’s safe to assume a compound is a heavyweight product. If in doubt, pick it up. A 5-gal. pail weighs around 60 lb., roughly 10 lb. heavier than midweight compound and 20 lb. more than lightweight compound.
When I embed tape and corner beads or when I complete plaster repairs, I use heavyweight compound. I also like it for texturing walls or ceilings by hand or for using spray equipment. Because heavyweight compound has a higher water content than lighter compounds, it shrinks more as it dries. This means fastener holes and drywall damage could require more coats of compound to achieve a perfectly smooth finish.
When it’s dry, heavyweight compound provides the hardest finish of the three, which makes it the most-difficult compound to sand; it also is the most resistant to scratches and other damage.
By adding expanded perlite to their compound formula, manufacturers produce a lightweight compound that weighs about 35% less than heavyweight compound. It’s designed to make taping easier because you don’t have to break your back lugging around a heavy bucket of mud. It also has a low shrinkage rate, so it requires fewer coats than heavier compound.
I use this compound for fill and finish coats because it smooths and feathers easily. Lightweight…