Maule fabric tester?

[JimS]

Has anybody used a Maule fabric tester? Our Chapter just bought one. What are the specs for checking the 1.8 oz. fabric or where could I find them?

JimS

[ackselle]

Here's a link to the AOPA article about fabric and minimum strength requirements:

http://www.aopa.org/members/ftmag/article.cfm?article=1386

"All fabric weakens with age. Fabric strength testing uses a device called a Maule tester, named for its inventor, B.D. Maule. The Maule tester is a calibrated cylinder with a tube and a spring inside and an anvil-shaped protrusion at one end. You push the anvil against the fabric and read the fabric's strength (in pounds per square inch) on the outer scale. If the anvil punches through the fabric before the scale reads 56 pounds, the fabric fails the test. If the tester doesn't punch a hole in the fabric, the covering passes.
New Grade A cotton covering tests at around 80 pounds, but it can deteriorate to 56 pounds and still be considered airworthy. New synthetic covers test to around 130 pounds, and they can deteriorate to the same 56 pound minimum. Because Dacron fabric deteriorates at half the rate of Grade A cotton, not to mention its greater range of deterioration, the life expectancy of a Dacron covering job will be four to five times that of cotton."

The Poly-Fiber "How to Cover" manual also discusses 56 lbs as the minimum requriement for airworthiness.

Hope that helps!

Cheers,
Ackselle

[Dave Holl]

Question is do you remove the paint before testing?

[JimS]

Ackselle,
Thanks for the info. I have the polyfiber manual. I'll give it a look.

JimS