Maintenance & Restoration

Tips on Cleaning Logs
 
 
Cleaning Logs
 
How do I clean my logs?
1. Exterior Cleaning Lightly sandblast, sand, or pressure wash (the most often used method) new logs (see How To Power Wash Your Logs. When pressure washing, we suggest you used one of these three cleaning agents if you will be applying either a water-based or oil-based finish.

a. CPR
b. Bleach and Water A mixture of one part bleach and five parts water, plus one tablespoon TSP (Trisodium phosphate) cleaner (optional). Note Chlorine bleach is NOT environmentally friendly and can be destructive to the wood if it remains on the logs too long. Rinse well!
c. X-180
 
Apply cleaning agents from the bottom and work up. This will avoid streaking of the logs. Allow agent to stand 10-15 minutes before power washing. Rinse thoroughly. Allow to dry 3-7 days depending on drying conditions before applying stain. Note When using CPR, Bleach and Water, or X-180, be sure to thoroughly rinse the cleaning agent after cleaning and then allow the log surfaces to thoroughly dry before applying finish.

 
After cleaning, you will notice a woody pulp on the surface. This can be removed by hand with a 3-M stripping pad or a quicker method is using an Osborn buffing brush on an angle grinder or car buffer. Usually two brushes are required for a house. If you did not use a sap-stain control, you may notice sap-stain, a blue, red, or brown coloration deep in the wood. These are permanent stains and unfortunately can not be removed.

 
2. Interior Cleaning Cleaning on the inside may be more messy than on the outside, if the house is already furnished. A general dusting may work, but to actually clean the logs, a sponge saturated with a bleach and water combination may be used. The logs will need to be rinsed, hence the messiness. A trough could be built to catch any of the dripping water when rinsing, or use another sponge with plain water. Otherwise, just a light sanding is necessary.

 

  
Why You Should Power Wash New Logs

As is true for most any job, proper preparation is as important as doing the actual job. This is certainly true for properly preparing the exterior surface of logs before applying stain to them. The leftover mill glaze* must be removed, and the surface should be slightly roughened to allow the stain to penetrate as deeply as possible. *Mill glaze is the stain-repelling film leftover from shaping the logs in the processing mill.
 

One way to understand the importance of this step is to realize that it is very rare to ever have any failure of a coating applied to the cut end of a log. The log end is extremely rough in texture, and the coating has ample opportunity to penetrate and establish optimum adhesion. The goal of power washing is to stimulate the texture without dramatically affecting the log's appearance.

 

How To Power Wash Your Logs
Power washing is shown being done on new construction. Notice how loose bark, mildew, and graying is removed.
 

 
Tips on Cleaning

A Suggestion For Applying Cleaners Mix the materials thoroughly in a pail or sprayer. Wet down the logs with cleaner from the bottom working upward. This is done so that any material running down will be onto a wet surface so that streaking is prevented or minimized. Wet down only the area that you will work in the following hour. If heavily weathered areas exist, scrub in and then rinse. Residues could cause adhesion problems with some cleaners. Many prefer to use a pressure washer to rinse and scrub. If you choose to use one, a 500-1500 psi washer is sufficient in most cases.

 

Oxalic acids like X-180 leave more color in the wood while chlorine bleach can blond the wood. If this happens, you may need to apply a pigmented finish to re-color the wood.
 
Oxalic acid mixtures will also help remove iron stains. (See X-180) This material leaves more of a golden color to the wood. Use an oxalic acid based cleaner only if you will be finishing your logs with a solvent-based stain or with water based finishes if the X-180 is Thoroughly rinsed off.

Neutralize the bleach with clear water, or the salts in the bleach could remain to feed future fungi.

Use a more diluted mixture on softer, more porous woods like cedar. Example Use a mixture of 1 part bleach to 5 parts water. On heavily weathered wood, you may need to use a 1:3 mixture. 

If you choose to use TSP as a cleaner and use it in heavy amounts, it can pull out the reddish undertones in Red Pine (Norway Pine). This red undertone can react with yellow finishes to give stains more of an orange appearance.

 
Power Wash Only The Exterior The interior surfaces are not critical, since they see no exposure to extreme weather. To avoid damage to interior areas, power wash the logs in the yard before they are shipped to the job site. If it is not possible to clean the logs in the yard, it should be done early in the construction cycle at the job site.

Use A 1500 PSI Power Washer Extremely high pressure is not necessary since you run the risk of tearing up the surface and leaving it with a “fuzzy” or “hairy” condition. This will not hurt the performance of the stain, but it can be objectionable in appearance.

Use A Low-foaming Detergent The detergent will assist the high pressure water in loosening and lifting all surface residues. Use hot water. Then rinse with cold water to flush any detergent from the surface. A garden hose works well for this.

Use A Fan Spray Nozzle Apply the water at an angle so it does not spray back into your face (be sure to wear safety goggles). Hold the nozzle at a distance, just far enough away from the surface to avoid “fuzzing” up the outer layer of wood. At this distance, the water and detergent will impact the wood with tremendous force and will remove virtually all residues, as well as creating considerable micro-roughening of the surface for enhanced stain penetration.

Apply The Finishing Touches If you will be applying PeneTreat, apply it once the logs have become slightly damp after cleaning. Caulking the checks and cracks may be done at any time after the cleaning operation is complete and the logs are dry.

Note The most effective method for removing mill glaze and roughening the surface is sand blasting. But for many, this approach is too expensive or impractical. If this is the case, power washing or sanding the logs will remove the mill glaze.
   
Should I Sandblast My House Before Staining?
Sandblasting and now, Cobblasting can be done to remove the old finish that previously exists on your log home. Both methods are a solvent free way to remove finishes but remember that windows and trim need to be properly masked off to avoid any damage.
Cobblasting is an innovative new way of stripping logs by using "grit-o-cobs" (dried corn cobs), instead of sand. Cobblasting is less abrasive than using sand and can be used as mulch for a garden or around plants when the job is done (if the stripped finish doesn't contain any lead). Typically with sandblasting the sand has to be hauled away adding extra expense. Cobblasting won't pit the logs the way that sandblasting will (a light sanding is all that is required so that absorption of stain is more uniform) and so you can save time and expense by not having to sand the logs down so heavily. Because cobblasting is new to the market, it may be difficult to find someone who offers that service in your area. We carry the KERNEL Cob Blaster for those of you who are interested in purchasing.
 
Because sandblasting leaves the log surface with a pitted texture, it should be sanded down to bring the surface back. If you have your house professionally sandblasted, it would probably be wise to find out if the company has had previous experience with blasting log homes. The pressure required for sandblasting logs is considerably less than for blasting metal. You wouldn't want them to blast huge chunks out of your logs.		   We Recommend Blasting If

You have limited time between removing the old finish and applying a new one. (You don't have to wait for the logs to dry like you would with chemical strippers).

Your home is near lakes or rivers where run-off could potentially pollute.

You are concerned about chemicals harming plants around your house.

You don't feel comfortable handling chemical strippers.

You have a very heavy coating making other methods of removal difficult.
   

Steps To Cleaning, Applying a Finish and Caulking a New Log Home

  

Steps To Cleaning, Re-Applying a Finish and Caulking The Exterior of Your Log Home
   
Exterior
Cleaning Lightly sandblast, sand, or pressure wash the new logs. When pressure washing, we suggest you use one of these three cleaning agents
 
CPR

Bleach and Water A mixture of 1 part bleach and 5 parts water, plus 1 Tbs. TSP cleaner (optional).

X-180
 
Apply cleaning agents from the ground and work up. This will avoid streaking of the logs.
 
Allow to stand for 10-15 minutes before power washing.
 
Rinse thoroughly!
 
Allow to dry 3-7 days, depending on drying conditions before applying stain.

 Preservative Apply preservative. Depending on type, some can be applied when the surface is damp. Oil preservatives will require dry wood.
 
Finish A pigmented coat of water repellent stain will last longer than clear. Apply one coat (2 coats can be applied if moisture content is under 19%) in the first year. Apply a second coat in year 2 only if in year 1 the moisture content is not below 19%.
 
Caulk or Chink On dry wood - Caulk or Chink in year 1.
On green wood -Caulk or Chink in year 2. This allows for more drying of joints to guarantee that caulking or chinking is not over stressed by small caulk joints and excess shrinkage.
 
Interior
 
Cleaning
Same as exterior, or wash by hand or light sanding. Interior may be wiped down more often, so a smoother surface may be desired.

 Preservative On the Interior, a preservative is optional on year-round homes but highly recommended to help deter insects on seasonal homes.

 Finish Clear finishes can be applied to the interior of the house. It is recommended to use a light pigmented stain if there is a lot of sunlight coming into the building. On dry wood (below 19% moisture) apply 1 to 3 coats to the logs to obtain the desired effect.

 Caulk or Chink
On dry wood - Caulk in year 1.

 

  
Caulk or Chinking Inspect the caulking before power washing and re-apply only where it is cracked or broken away from the logs. It is important to do this first so that when you power wash, you are not forcing water into the joints of your logs.
 
Cleaning Pressure wash the logs with water.
If the logs are sunburned see Avoid Peeling Finishes and Sunburned Logs. If the logs have not been restained for so long that they have turned gray, then we suggest you use one of these three cleaning agents before the pressure washing:
 
CPR

Bleach and Water A mixture of 1 part bleach and 5 parts water, plus 1 Tbs. TSP cleaner (optional). Use a garden style pump sprayer with a fan tip.

X-180

 
Apply cleaning agents from the ground and work up. This will avoid streaking of the logs.
 
Allow to stand for 10-15 minutes before power washing.
 
Rinse thoroughly.
 
Allow to dry 3-7 days, depending on drying conditions before applying stain.
 
Finish A pigmented coat of water repellent stain will last longer than clear. Apply one to two coats.
Note Water based stains can not be used over oil based stains, when in doubt, use an oil based stain.

 

 

Thanks to Schroeder Log Home Supply, Inc. for the information that has been provided on our site.

Please visit their webpage for more information and products.

 

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