Stains on wood surfaces - not to be confused with wood that is purposely colored with "wood stain" - can be a problem. Below, Woodworker's Journal editor Rob Johnstone and finishing expert and author Michael Dresdner field an unusual question on getting rid of unwanted stains on cedar trim.
Q. I'm currently building a post and beam house that will be finished inside with cedar trim. Unfortunately, one of my boxes of cedar trim housed a family of mice for a few months and they urinated on several pieces of the cedar trim. Do you have any ideas how I could clean this? It stained the wood as well as the bad smell. Of course they picked the most expensive box of trim.
A. Rob Johnstone: “We hate meeses to pieces! Nasty little problem you've gotten tangled up in. I am no expert on the discoloration, but think sanding would probably do the trick. As for getting rid of the smell of urine ... here I claim some expertise. I have three dogs and a cat at home. There is a product available at pet stores called Natures Miracle. It is an enzyme based cleaner that works ... well, if not miracles, the next best thing.”
A. Michael Dresdner: “Remove the stain, as much as will come out, with oxalic acid or woodbleach, and seal in the odor with Zinsser SealCoat or dewaxed shellac.
“The most likely cause of the stain is the ammonia in urine, which colors any wood that contains tannin, including cedar. There is no guarantee that the stain will come out, but oxalic acid is a good first attempt. If that doesn't work, you can resort to wood bleach, which will probably remove the stain, but will de-color the wood as well, forcing you to stain it to match the other pieces. Sealing the wood with Zinsser SealCoat, or any shellac, for that matter, will lock in the odor.”
From the Woodworker's Journal eZine 2004 archives
We can't think of anything to add - short of trying to explain to the mice just how expensive cedar has become in the last several years and offering them a comparable quantity of ponderosa pine. We do offer a range of supplies designed for those times when bad things happen to good pieces of wood in our Refinishing/Repair category, including our Furniture First Aid Kit, which is a good thing to have around in case of wood finish emergencies. We also have a complete line of wood finishes and sealers - including the Zinsser SealCoat mentioned above. It's an excellent all-around sealer, even for wood that hasn't been mistreated by a rude rodent.