setting iron temp.

I'm having trouble setting my big iron temperature. It's the kind you get in the covering kit from Aircraft Spruce. I broke their cheap thermometer and bought one of those laser pointer digital thermometer. Cool tool but when I point it at the iron it never reads anywhere near 250 -300. When I place it down and point it at the service I'm ironing, it reads higher 250+. Don't really know how to tell what it really is....
When I point it at the small iron it reads correct. High = 375 or so and I can dial it down to get a constant 250 or so.

How have any of you set your iron heat temps?

Thanks, again, Don.

Don, I followed the calibrating instructions in the April, 1998 Poly Fiber manual. A candy thermometer encased in heat sink compound on a thick pad of paper towels.

I used a sunbeam iron recommended in the manual until I wore the teflon coating off the point then finished the covering with a 15 dollar black and decker iron.

Norm Douthit told me how to take an ordinary candy thermometer and touch the glass casing to my bench grinder and it will shatter off leaving the thermometer spruce sells for about ten times the money.

I would now use the pointer type thermometer like you have. You will have to point it at the iron and hold it there for a little while as the iron heats up to the setting the control is set at. It will climb up to that temperature and the thermostat will shut it down until it cools a few degrees then back on again.

Always turn the control the same direction (up) to the setting you have marked. There is slop in the control so if you set it to the mark by turning the control a different direction it won't be the same temperature.

Calibrate it with the extension cord you are going to use and don't change cords.

Always turn the control the same direction (up) to the setting you have marked. There is slop in the control so if you set it to the mark by turning the control a different direction it won't be the same temperature.

Calibrate it with the extension cord you are going to use and don't change cords.[/QUOTE]

Thanks for the tips, Steve.
I'll keep trying.
Don

Hi Don, EAA has a very good video on explaining the calibration procedure. This is what I used. Here is a direct link:

http://link.brightcove.com/services/...id=13520259001

If the link does not work, go to www.eaa.org click on the homebuilders link then video tutorials. It is located in the "Tube and Fabric" section.

I used a digtial thermometer, your iron is going to have a temp variation on where you point your thermometer. Also as the thermostat clicks on and off. I would take 5 readings while the iron thermostat was on and 5 when it was off, and take the average.

Just don't expect to calibrate the iron in 3 minutes and 43 seconds like in the video. If I recall correctly it took me half a day the first time. I also calibrated it for 300 and 325.

you can bend the airframe on a kitfox at 350. I think stopped at 300 degrees on the fuselage and I got to 325 on the wings before the trailing edges started to pull in.

Have someone hold a straight edge on the trailing edge and when it starts to pull away stop right there.

Mine is a 1994 Classic 4. Maybe the big new ones can take the heat of 350.

If the digital theromometer you mention is the infrared type, they will not register correctly pointed at a shiny surface. If your iron has an aluminum surface it won't work

Now you tell me! lol
Thanks, really. it's back to the candy thermometer.

FOUND THIS.
http://www.coverite.com/accys/covr2410.html

I'll tell you how I calibrated mine. I took a piece of aluminum about an 1x1.5x.5 inches, drilled a hole in it near one edge about the size of the thermometer bulb, then mixed some epoxy with some aluminum filings in it and glued the thermometer into the aluminum block with the calibration markings on the same side as the thinner block edge. Then a thickly folded towel was put on the counter with the thermometer block combo facing numbers up. Lay the iron on the towl with the thermo numbers visible and it is easy to watch the temps cycle.

Keep in mind that when shrinking, any fabric surface that has backing - wing tank, trailing edge - will act as a heat shrink and getting that fabric to the right shrink temp might require a tad more heat to get it right.