: The shop I am stripping in has a pretty good amount of sawdust in
: it most of the time. I started using a heat gun today to bend
: strips for the tail of the baidarka I'm building, and looking at
: the background of the path of the heat gun looked like it could
: be a fire hazard.

: Any guidelines of safe heat gun use when it comes to being in a
: area with lot of flammables?

You need a lot of fine dust to meet the lower explosive limit. I wouldn't worry about using a heat gun.

From http://www.wclib.org/pdfs/msds6_95.pdf

FIRE & EXPLOSION DATA
Flash Point...........................Not Applicable
Autoignition Temperature.................Variable
(typically 400-500°F)
Explosive Limits in Air.....40 grams/m
3
(LEL)
Extinguishing Media...........Water, CO2
, Sand
Special Fire Fighting
Procedures...................Wet down with water
Wet down wood dust to reduce likelihood of
ignition or dispersion of dust into the air.
Remove burned or wet dust to open area
after fire is extinguished.
Unusual Fire &
Explosion Hazard.................Strong to severe
explosion hazard
(if wood dust "cloud" contacts
an ignition source)