CPR FAQ’s

• Q: What can I do about blue stain?

  A: Once blue stain has established itself, it is nearly impossible to completely remove it. It can be lightened up using various bleaches, such as Sashco’s CPR (sodium per carbonate), a 35% hydrogen peroxide cleaner, chlorine bleach or oxalic acid. However, it is virtually impossible to return the wood to its original appearance.
  Contact Whisper Creek Log Homes Customer Service or call them at 1-800-767-5656 to discuss your particular circumstances.

• Q: What can I do about blue stain?

  A: CPR is a sodium per carbonate cleaner, which, when dissolved in water, releases hydrogen peroxide – which is an oxygen bleach as opposed to a regular chlorine bleach. Oxygen bleach is significantly less environmentally harmful and dangerous than chlorine bleach or oxalic acid, yet can do an excellent job of cleaning and bleaching. While it needs to be thoroughly rinsed from any wood it is applied to (just like chlorine bleach or oxalic acid), there is far less risk of damage to wood or stains when a little oxygen bleach is left on it than with other chemical cleaners.

  CPR should NOT be used on Redwood, Hemlock or other high-tannin woods, as it can cause severe discoloration of the wood. In addition, it will discolor some Cedar wood so should therefore be very carefully tested prior to use on a Cedar home of any kind.
  NOTE: When using bleach of any kind, make sure you test a small area before proceeding with the entire project. Oxidizing chemicals can cause undesired color shifts, including tannin bleeding, in various woods. You should be prepared to use whatever cleaner or bleach will work without causing unwanted color shifts. And, if using acids on wood (i.e., oxalic, phosphoric, acetic, hydrochloric, etc.), the wood should be thoroughly flushed with water. Then a solution of baking soda, like the Arm & Hammer brand, should be applied to the wood to neutralize any residual acid, followed by a final rinse of the wood with a large amount of water. Be sure to vacuum out or blow out standing water left in dead-end checks so water does not sit and soak into localized regions of wood. Unsound wood should be mechanically removed

• Q: What can I do about blue stain?

  A: No. In fact, when applied to old chinking, it will likely help clean it and brighten it up.