A.Charles Young, a technical service representative with Georgia-Pacific Gypsum in Atlanta, responds: In a typical residential shower, it is acceptable to skim-coat DensShield tile backer (Georgia-Pacific Gypsum, 800/225-6119, www.gp.com/build) with a setting-type joint compound — such as Durabond (USG, 800/874-4968, www.usg.com) or Georgia-Pacific's ToughRock 45 or 90 — to get a smooth, paintable surface in areas that aren't tiled.
Since these compounds set by a chemical reaction and are very hard when they cure, you might be tempted to use a sandable version. But sandable setting compounds are not recommended in this application, because they don't set as hard as regular formulations. Use 2-inch 10x10 glass-fiber mesh tape (not paper tape) at the corners and wherever...
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