Log Jam Chinking

Fundamental Chinking Application Guidelines
Proper substrate preparation and application are imperative for product longevity. Read this instruction sheet before applying any product.
1. Best results are obtained when Log Jam is applied to clean, dry, stained wood. Make certain there is compatibility between your stain and Log Jam. Log Jam has a lifetime warranty when applied with Sashco’s stains: Capture Log Stain / Cascade staining system, Transformation Stain Log & Timber and Symphony Interior Clear Coat.
2. Check the weather forecast. Finishing products are best applied in moderate weather conditions, i.e., out of direct sunlight, in dry, warm conditions.
3. Check the log surface temperature. The surface temperature should be between 40 ̊-90 ̊F (4 ̊-32 ̊C). Install a bond breaker before Log Jam is applied. Backer rod, Grip Strip, and clear packing tape all perform this function well. If Log Jam is applied over white styrene bead-board or Tyvek™ house wrap, it is best to cover the bead-board or wrinkle-free house wrap with clear packing tape (to prevent adhesion to those materials). We do not recommend the use of blue or pink extruded polystyrene board as a bond breaker.
5. Gun the chinking over the backing material. Ideal sealant depth is half of the joint width, but no less than 1/4”, nor more than 1/2”.
6. Tool Log Jam to ensure good contact with the log surfaces, especially to the upper log; this will greatly aid adhesion.
7. All chinking products may occasionally “blister”.

To avoid blistering:
• Do not apply in direct sunlight.
• Protect fresh chinking from direct sunlight for 1-2 days after application with white plastic sheeting tacked over it.

Surface Preparation
• Best results are obtained when Log Jam is applied to wood that has been previously coated with a compatible and thoroughly cured stain.
• Clean the log surfaces thoroughly to remove dirt, pollen, bird droppings and other surface contaminants.
• The USDA Forest Products Laboratory and other researchers around the world have reported that surface wood exposed to sunlight for as little as 1-2 weeks can become significantly damaged and unsound, which may lead to premature adhesive failure of the stains or other coatings applied to it. It can also hurt Log Jam’s (or any chinking’s) adhesion to the surface. Once bare wood has been properly cleaned and prepped to remove unsound wood, stain should be applied as soon as possible. Follow with Log Jam chinking.
• If a stain is applied over Log Jam, it will be tinted the stain color, but will be affected differently than the surrounding wood; therefore, test appearance before wide-spread use.
• A few coatings, especially those high in wax content or non-drying oils, may interfere with adhesion, whether they are applied before or after Log Jam. We advise against using Log Jam with such products.

Cold Weather Chinking
Log Jam can be applied in cold weather by following these instructions:
1. Make sure the log surfaces are above 40 ̊F (4 ̊C). Use a surface thermometer to double-check.
2. Keep the chinking at room temperature until ready to use.
3. Make sure the logs are free of frost.
4. Tent out the walls with clear plastic sheeting and keep them warm with heaters, then apply chinking.
5. Make sure there is air circulation so moisture doesn’t form on the logs, causing a washout. Some venting up high will help with this problem.
6. Leave the tent intact day and night while chinking, and for 2 to 4 days after chinking is complete.
7. Finally, remove the plastic sheeting. This should be sufficient to let the Log Jam skin over and slowly cure. Due to cold temperatures, it will take much longer than normal for the Log Jam to fully cure, but it will be fine if left undisturbed. Warn people to avoid pushing on it for several weeks.

Methods of Application
• When using 5-gallon pails, Sashco’s Snorkler chink pump, grout bags or bulk loading guns may be used.
• When using a cartridge, cut the spout at a 45 ̊ angle to desired bead size.
• In wider joints, multiple beads may need to be run until the entire joint is filled with chinking.

Tooling
When applying Log Jam in temperatures below 70 ̊F (21 ̊C), a mixture of 1-part denatured alcohol to 2-parts water can be used for misting the chinking immediately prior to tooling. When the temperature is over 70 ̊F (21 ̊C), water alone will be sufficient.

The techniques discussed below will give an aesthetically pleasing chinking line, as well as ensure a proper seal between the Log Jam and the log surface.
• Tooling Log Jam on Round Logs: Work the material smooth with a damp foam brush, keeping a rag handy to clean up drips of water and excess Log Jam.
• Tooling Log Jam on Square Logs: Use a putty knife to strike off excess Log Jam, making the joint level with the logs. Use a damp foam brush to smooth the material, keeping a rag handy to clean up drips and wipe off excess Log Jam.

New Construction Joint Design
• An hourglass profile is the ideal type of joint design for all sealants. It allows for maximum sealant movement and favors cohesive failure (the best kind) if the movement is so extreme that failure cannot be avoided.
• Round backer rod is best, especially when substantial movement is expected, as with “green” logs.
• The chink line should be no less than 15% of the log width. For example, with 10” diameter logs, the chink joint should be about 1 1/2” wide. If you choose to apply a smaller bead, expect more chinking repairs.
• Ideal sealant depth is half of the joint width, but no less than 1/4”, nor more than 1/2”.

Restoration
• Wood should be clean and stained, as discussed in the Fundamental Chinking Application Guidelines section.
• Remove all loose mortar.
• Bond-Breaker: When using Log Jam as a restoration chinking over old mortar, cover the old mortar with clear packing tape, which provides a surface Log Jam will not stick to. When movement occurs, the Log Jam will be free to stretch.
• Tooling: Log Jam should be tooled to contact at least 1/2” of the bare wood surface on either side of the old mortar. This will ensure adequate adhesion.

Slab Siding
Slab siding can pose a special challenge due to the very rapid and large amount of movement it often exhibits after being installed. This movement shows up as extreme shrinkage, bowing and twisting, and can stress sealants more than logs do. To help reduce this problem, follow these additional tips with slab siding:
1. Use only dry slab siding (19% or less moisture content level, verified with a moisture meter)
2. Install the siding with heavy screws, not nails.
3. If applying over Tyvek house wrap, make sure the Tyvek is wrinkle free and tape over it with clear packing tape.
4. If the boards are thick enough, install Half Rod backer rod with the round portion of the profile facing out. This will provide for the best joint design.

Blisters
Blisters are a common phenomenon with chinking and caulking products and are caused by a variety of things. Blisters appear as “bubbles” in the chink line and can vary widely in size. To help prevent blisters, shield freshly chinked walls from the sun with white tarps. If this cannot be done, keep a close eye on the chinked wall for the first 24-48 hours. If a blister begins to develop:
• Pop the blister and gently push the material back into place
• 3 to 5 days later, apply a skim coat of Log Jam and tool to blend in.

Cleanup and Disposal
• Dispose of Log Jam in accordance with local regulations.
• Do not dispose of in drinking water supplies.
• Hands, surfaces and equipment may be cleaned up with water.