Monday, February 13, 2012

Deep Freeze

Deep Freeze
By Tim Ard, Forest Applications Training, Inc.

Winter has been kind of elusive this year but I'm certain its on the way back...

I travelled up to Highland Park, IL a couple weeks ago. They've had some snow but I couldn't believe, when arriving in February, it was going to be over 50 degrees. That's my kind of winter! Chicago usually has to deal with a deep freeze and it's when they do most of their tree work. The off-season for parks is when tree maintenance and clean-up work happens in cold country.

Questions this time of year- How does cold weather effect tree and limb control? Saw chain?

It's important to understand the deep freeze because ice and snow storms will be back....

Let's start with the easy one, Saw Chain.

Super-cold can make lubricating saw chain and the guide bar a challenge. It can work, but it's sometimes a challenge. Rapid saw chain chassis wear and bar rail flaring or peening can occur because of the cold weather lube breakdown.
Frozen wood is wet wood. Water and saw chain are not ideal partners. This situation makes lubricating tough and rusty saw chain is never your friend.
Frozen wood is hard on saw chain. It dulls saw chain more rapidly. Ice coated wood rolls the edges and point if you apply pressure. You must let the chain do the work in deep freeze situations.

Now, what about the wood...
Cold weather doesn't really freeze the wood fiber. It does freeze the moisture content of the wood. The crystallizing and expanding moisture makes the wood fibers separate and in turn break easily when they are moved, or should we call it stressed during movement.
Many frozen fibers seem to react like rotting or dried brittle fibers. They move very little before breaking. You know fiber must be flexible to be a plan-able control factor.
So important to use a perfect notch opening to allow this somewhat inferior fiber situation to perform to your expectations. An Open-Face notch of 70 degrees or more will allow the fibers to perform without resistance.
Level back cuts will lessen possibilities of fibers collapsing as the kerf is made. A back cut level to the notch apex limits vertical movement. Fiber collapsing, as it breaks from back to front, cause these holding fibers or hinge to prematurely fail.

To maintain safety and control, hinge fiber is mandatory. Understanding how to deal with different fiber conditions can be challenging. However, in the deep freeze, the path of little resistance is the best technique.

Send any questions you may have to timard@ForestApps.com Visit our training website at www.ForestApps.com .



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