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How many MIRRORS to kill a tree..??

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Posted by Robert on November 27, 2004, 12:32 am
I want to kill off a large branch at the top of a Maple tree in my
yard which is growing in the path of my satellite dish. Cutting the
tree, or moving the dish is not an option.   My question to the
mirror-saavy audience, is... can I focus enough common-store-variety
flat-silver mirrors to kill a tree branch..??

My evil plan is to wait for a nice clear, hot, early-summer
day...probably early July, or so, when solar rays are maximized...
with friend & neighbors together, I thought 20-30 2-foot-square
mirrors would heat this branch hot enough [150-160F] within 10-20
minutes..??  Shooting distance from the roof of my house to the
tree-top branch is probably 60-70 feet.  I'm in Michigan; 43lat...
can somebody tell me if this is a totally nutzo idea...or can it

thankx for your input...Robert

Posted by Duane C. Johnson on November 27, 2004, 2:39 am
Hi Robert;

Do you mean like this?

     Home of the $5 Solar Tracker      Receiver
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Posted by Robert on November 27, 2004, 2:16 pm

Yeh... exactly like that... problem is, the heliostat array in the
deathray link uses over 300 sq.ft of mirrors....  I have access to
maybe 1/3 that much; but I only need to KILL the tree branch... don't
need to ignite.  The water in the live branch is what absorbs the
satellite signal.   There was one reference on your 'redrok' site
about Archimedes:

"calculated that a one foot mirror would provide only 2000 calories
per minute even at 100 percent reflection and, argues Stavroudis, this
will only raise the temperature by a few degrees per minute"

given this as a general reference... a 100sq.ft. heliostat should
easily get temperature to a 1ethal level on a hot summer day..??...
probably should have some beer handy, just in case something DOES get
too hot..!!!

thankx for the link...  I had already looked at your site, but there's
a lot of stuff there... I missed the deathray....  Rob

Posted by oh thats me on December 1, 2004, 4:04 am
 cheaper  way of doing it is using copper boat building nails    (wink wink)

Posted by Me on December 1, 2004, 7:22 pm

How about a CAINSAW???????


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