"Douglas, Brent" wrote: > > ok, i tried a rollfuz last nite - 2 things stick out..... > > i was really guessing at how much glass to use... i went with a layer of 1.5 > kevlar, a couple wide strips of uni carbon, and a layer of .7 glass.... > > it seems relatively strong, but for a handlaunch (maybe discuss) body (about > 2" circumference at the wing, 3ish feet long) - but, i am open to > suggestions. > > also - BAD idea to bag it.... i turned on the pump and watched it crumple: > oh yeah, its HOLLOW. doh. was able to 'inflate' it, manually. dont ask. > > any direction from someone out there that has tried this? > > thanks, > brent Brent: The idea behind the Rollfuz method was to prepare a sandwich of glass or other material, between layers of acetate, which could be rolled out to eliminate excess resin or air bubbles prior to rolling a boom. Because of this no vacuuming is required and the resulting boom takes on the finish of the acetate. As for typical lay-ups the following is what I use: HLG Nosecone and boom - 1 layer 1.5 oz and 1 layer 4.4 oz. This is reinforced with 5 or 6 longitudinal strips of kevlar tow. weight of boom and cone 37 gm. 1.5 M slope and 2M thermal - 1 layer 1.5 oz, 1 layer 6.0 oz unidirectional cloth and 1 layer 4.4 oz. cloth with kevlar tows. 100" thermal - 1 layer 1.5 oz , 1 layer 6.0 oz unidirectional, 2 layers 4.4 oz cloth with kevlar tows. 3 M Thermal or FAI 1 layer 1.5 oz, 2 layers 6 oz.unidirectional, 2 layers 4.4 oz. These are guidelines and I vary the lay-ups a little, depending on the anticipated stresses anticipated on the model. -- John O'Sullivan Nova Scotia Wind and Wave Models http://members.nbci.com/WindandWave/ RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
