At 11:29 PM 8/24/2006, you wrote: > Why do Prop makers tighten their layers of wood together so > tightly when making a prop if it is a bad idea ? > Have you ever been in a prop shop. There used to be one near me > here in Caddo Mills Tx and they used house jacks to tighten the > wood together and left it that way until the resin/glue cured. I > have no idea what glue they used but what takes more of a beating > than a propeller taking pulses from the engine and air it is moving > through, besides trying to sling itself apart. Just wondering ? > Maybe their glue is really thick resin ? and will not all squeeze out. > Larry H.
Required clamping pressure is dependent on the type of glue. Certificated wooden props must be built exactly the same way that they were certificated. Certificated wood glues must be applied exactly as specified. Resorcinol glue is certificated and requires fairly high clamping pressure; whereas, T-88 can be used to make repairs in a certificated airplane if you prove to the AI that it is an acceptable method but it must not be subjected to high clamping pressure. The short answer is: read and heed the manufacturer's directions. They know a whole lot more about it than you or I do. Don Reid - donreid "at" peoplepc.com Bumpass, Va Visit my web sites at: AeroFoil, a 2-D Airfoil Design And Analysis Computer Program: http://aerofoilengineering.com KR2XL construction: http://aerofoilengineering.com/KR/KR2XL.htm EAA Chapter 231: http://eaa231.org Ultralights: http://usua250.org VA EAA Regional Fly-in: http://vaeaa.org
