Everybody agrees that back-priming wood siding improves the durability of the exterior-surface finish and the longevity of the wood. But I’ve seen siding installers ignore this important step because it adds the expense of the primer and the time required to apply it. For those of us who like to be frugal yet still do the right thing, here’s a way to reduce the expense of the primer: Use mismixed latex/acrylic exterior paint or stain from paint stores. This is the paint that somebody had custom-mixed, then had a change of heart about. Because I can’t see it on back-primed siding, I don’t care what color it is.

Here in the Twin Cities metro area, one local paint distributor offers these mismixed gallons of paint for free rather than pay for approved disposal. Other stores sell it at a greatly reduced price.

A caution: Some recycling centers and used-building-material stores also offer used or donated paints and stains for free or for a low cost. These finishes may be acceptable for theater props or other temporary uses, but not for application to a building. Don’t risk premature paint failure by using paint that may have been frozen, diluted, aged, or otherwise ruined. This reason is why paint stores themselves are the best source for these free or low-cost finish alternatives.

Bruce G. Koprucki, Chaska, MN