The proportion of heartwood to sapwood in the main stem does vary with species. Black locust, for example, usually has a very narrow band â often less than an inch â of functioning sapwood, whereas maple stems often can have many inches of sapwood and relatively narrow cores of heartwood.he proportion of heartwood to sapwood in the main stem does vary with species. Black locust, for example, usually has a very narrow band â often less than an inch â of functioning sapwood, whereas maple stems often can have many inches of sapwood and relatively narrow cores of heartwood.
1 Apply stain only at the proper temperature. 2  For most stains, 70 degrees Fahrenheit is the optimum, with the safety range from 50 to 90 degrees Fahrenheit. 3  Stains do vary, so check the label first.o assure the highest quality results when applying exterior wood stain, follow these steps and helpful tips from Sherwin-Williams stain experts. 1  Use the right brush. 2  Use a natural-bristle brush for oil stains and a synthetic-bristle brush for latex stains.
The temperature of the wood before you apply the coating is important. If the wood is at least 50` you should be ok. You should also quit early in the afternoon so the stain has more time to dry before the dew hits.I'd be leery of staining a deck in cool weather 24 hrs before rain is expected.f the wood is at least 50` you should be ok. You should also quit early in the afternoon so the stain has more time to dry before the dew hits. I'd be leery of staining a deck in cool weather 24 hrs before rain is expected.