nuts & bolts
Calibrating Your Iron
Optimizing your fabric-covering tools
FROM THE ARCHIVES
CLAUDIUS KLIMT, EAA 11845
“The Shrinking Art of Fabric Covering”
can be read online in the EAA Sport
Aviation archives by visiting the EAA
Members Only page at
Irecently watched the EAA Hints for Homebuilders
video of the iron calibration of an iron for shrinking
fabric. Though I am no expert, I did try several methods
of calibrating my iron for the fabric work on my AirCam.
Here is what I found:
• It is difficult to find an iron that does not have all sorts
of fancy features like automatic shut-off and water-vapor
injection. It would be useful for you to spell out exactly
what model iron meets the fabric-covering needs best. I
explored the guts of an inexpensive iron and removed
all the automatic features, making it a simple iron with a
rheostat to control the heat.
• If you use an infrared heat-measuring device, the
iron should not have a reflective surface. Some irons
have a shiny silver bottom; some have a dark surface.
The heat-measuring devices will not work on a reflective
• Most important of all, if you check the temperature
of the surface of an iron with a heat-measuring device, the
numbers are all over the place depending on where you
point the measuring device on the iron. As I understand,
in order not to weaken the fabric, you must never exceed
350 degrees. It is important to make sure the hottest part
of the iron does not exceed 350 degrees. If you measure
the coldest part of the iron it could be 350 degrees, while
the hottest part is more than 400 degrees. The same goes
for the silicone system. If you select the wrong part of the
iron to measure, you could get the same wrong reading.
• An interesting thing is the range of temperatures
the iron goes through as its thermostat cycles through
its selected temperature range. If you leave an iron on a
specific heat setting, the thermostat has to drop a given
number of degrees before it will turn on again. The
temperature range of the iron surface goes through a large
range, depending on the iron. Fifty degrees is not unusual.
For example, it drops 50 degrees before it senses that it
needs to heat up again. If you measure the temperature
in the trough, the maximum temperature reached at that
setting is 50 degrees higher before the iron shuts off.
I would appreciate specific guidance regarding which
iron to use and exactly how to use the temperature-sensing
devices to calibrate the iron correctly.
Info From Poly-Fiber
We find that the Black & Decker F63D Classic provides good
value for your money with acceptable performance. When
using a non-contact temperature sensor, move it in a circular
pattern around the heat face, which also results in a reasonable
Irons are inaccurate tools, as
Mr. Klimt rightly points out. There
are many varying heat spots on
the heating face. We find that a
smooth motion of the iron averages
these spots out and results in
satisfactory average temperatures.
–Jon Goldenbaum, Poly-Fiber