How to Apply Log Jam Chinking (Sashco Instructions, Step by Step)

Sashco Log Jam is a flexible chinking that seals the joints between logs and stretches as the logs move. It's easy to apply if you get three things right: a bond breaker behind it, the right thickness, and good tooling. Here's how to do it, based on Sashco's own Log Jam instructions.

What You'll Need

• Log Jam chinking in cartridges or pails
• Backer rod (or Grip Strip or clear packing tape) as a bond breaker
• A caulk gun or bulk loader
• A damp foam brush, plus a putty knife for square logs
• A spray bottle of water (or 1 part denatured alcohol to 2 parts water below 70°F)

Step 1: Check the Weather

Apply when surface temperatures are between 40°F and 90°F. If rain is expected within 24 hours, be ready to cover the walls with plastic.

Step 2: Install a Bond Breaker

Sashco says to install a bond breaker before Log Jam is applied, so the chinking sticks only to the two logs and can stretch freely. Backer rod, Grip Strip and clear packing tape all work; round backer rod is preferred where the logs move a lot.

Step 3: Size the Joint

The chinking joint should be at least 1/2" wide and no less than 15% of the log width. The ideal depth is half the joint width, never less than 1/4" or more than 1/2" thick.

Step 4: Apply

Gun Log Jam over the backing material. Wider joints may need several beads side by side to fill completely.

Step 5: Tool It

Smooth the chinking with a damp foam brush on round logs. On square logs, use a putty knife first, then a damp foam brush. Below 70°F, mist the chinking with 1 part denatured alcohol to 2 parts water just before tooling.

Dry and Cure Times

• Tack-free: less than 30 minutes (70°F, 50% humidity)
• Full cure: about 3 weeks at 1/2" thick
• Paint or stain over it: after 24 hours with latex coatings, 5 days with most oil-based coatings

How Much Log Jam Do I Need?

Per Sashco, a 5-gallon pail covers from about 770 linear feet on 1/2" joints down to about 45 linear feet on 4" joints. A 29 oz cartridge covers from about 35 linear feet on 1/2" joints down to about 2 linear feet on 4" joints. Measure your total joint length and width before ordering.

Cleanup

Hands, surfaces and tools clean up with water.

Chinking vs Caulking

Chinking like Log Jam fills the wide joints between logs. For checks, cracks and smaller gaps, use a log caulk like Sashco Log Builder or Conceal. Then protect the logs with a log home stain; see our log home stain guide.

Questions? Email Sales@TheStainDepot.com.