THE CHEAP LITTLE SUCKER

	A vacuum pump for less than $25 - why not? After looking around for different vacuum
bagging kits selling for as much as $300, this 24 year-old Berkut builder decided to use a little Texan
Jerry-rigging. The resulting contraption is something I call "The Cheap Little Sucker." Seriously,
vacuum bagging is the best way to build your aircraft light and strong - with the cost barrier broken and
using Dave's techniques, there is no excuse.

	I first told Dave about the pump solution at Fun & Sun '93. After he picked his jaw up off the
floor he asked me to impart this knowledge to you - so here it is: Let me start by telling y'all that there
are several different ways of accomplishing the same goal. Some of you may wish to alter this idea -
feel free!

Start by locating one of the following:
	1.	Refrigerator Freon Compressor (Sealed Unit)
	2.	Automobile Air-Conditioning Compressor and Electric Motor

	In my opinion, the Refrigerator Freon Compressor (RFC) is the best overall choice. The
refrigerator unit is quiet, compact and produces little heat. The auto compressor is piston based,
produces large amounts of heat and requires an external electric motor. Again, whatever is easiest for
you to acquire. My compressor came from a keg cooler that had been scraped because the thermostat
was fused and it froze the beer. Look for junk yards, garage sales, and yes - the side of the road. "One
man's junk is another man's treasure." You might be amazed where you can find a dead 'fridge.
(Remember - the compressor must be operational, but the case, coils, and other parts will be discarded).

	Remove the compressor from the fridge and carefully cut the coils free. The Freon in the
compressor will need to be re-cycled properly. Examine the wiring and make sure that it is safe. My unit
had a termistor (thermal fuse) still attached and operational. Moment of truth - plug it in and determine
which is the exhaust and suction sides. While it is running, I suggest squirting some WD-40 into the
pump to help replace the lost oil.

	The diagram shows the configuration I am using and contains several optional extras. As a
minimum, use a compression fitting to clamp the 3/8 inch diameter brass pipe to the suction side of the
compressor. Attach two T-fittings to the pipe and the compressor hose on the end. On the first T-
fitting I used a simple brass valve for the pressure relief The vacuum gauge I used is an automobile
Vacuum/Fuel pressure gauge ($15 part at the local auto parts store) attached to a nipple on the
outboard T-fitting. I had some air-compressor hoses so I incorporated a quick connect fitting to the
end of the 2nd T-fitting. This made it possible to use, disconnect, and interchange the existing hoses
with the air-compressor.

	Another optional improvement is an extension tube for the vacuum bag seen in the diagram. It
makes it easier to seal the bag and doesn't mess-up the end of a good compressor hose. Just food for
thought.

	"The Cheap Little Sucker" got its first workout on the two winglets and performed flawlessly. It
is very quiet and produces only a small amount of heat. It moves a good volume of air and seems to
take a puffy winglet bag down to 13" in 3-4 minutes. Be careful though, these compressors have no
problem pulling 30+ inches (enough to damage the foam).

	Well, there it is...earth shattering information fresh from the heart of Texas. If you have any
questions at all, feel free to send me an email: RedmonJ@airmail.net
Good luck and lets get those birds in the air!!!

James Redmon, CFII (Builder #013) and Tim Cook (Asst. Builder and Technical Advisor)