: While at work, our cats got muddy (now dried) paw prints all over my S&G
: plywood deck panels. Is light sanding the best way to get the dirt and
: discoloration out? Mike

Do you want to get the dirt and discoloration out of the cats by sanding them? Then would be cruel, as the cats would scratch the @#$#@ out of whoever was holding it.

Seriously, though. The surface of wood slowly oxidizes and accumulates a layer of cells that have changed color. If your panels have been around for a while, or have been exposed to the sun for a while (UV speeds this process) then if you just spot sand you may encounter some local changes in wood color. You may want to lightly sand the ENTIRE panel to keep the color even.

Depending on the size of the panel, this could be a lot of work, or maybe a waste of time. You may want to save the sanding until after the panels have been joined together, when you would be sanding them anyhow. Just make sure you don't embed a footprint under the glass tape and resin at the seams.

Test a small area to see if the muddy areas can clear up. You might try using a (rubber) pencil eraser, or an art gum eraser, or lightly hand sand with some fine sandpaper (no power tools) to see if it helps.

If the pawprints were very wet then the dirt might have been absorbed deeply into the wood. There are bleaches available to lighten such stains,(oxalic acid, household chlorine bleach, etc.) but it is hard to bleach just one irregular spot and make it match the surrounding area. If the sanding doesn't do the job you may want to use a stain to obscure the outlines of the pawprints and make them less noticeable.

Start storing your wood with the good side down. Otherwise your cats may come back on another damp day and repeat the problem.

PGJ