Brodhead Pietenpol Association

Original Posted By: shad bell
I'm with Gordon and the others... it makes more sense to add stiffeners where needed rather than making the whole piece heavier with multiple layers of glass to add stiffness. It was easy to do with the belly of my Flying Squirrel, for example... look at the 4th through 6th photos on this page - http://www.flysquirrel.net/update.htmlAll you have to do is lay some foam wedges inbetween the layers, or even add them after you've made the cowling and pull it from the mold to see where you need additional stiffness. It's amazing how much rigidity that 3rd dimension can add to a flat layup.One other thing that people have told me is to use peel-ply on your layup (assuming you're laying up over a male plug). It absorbs excess resin as well as providing a much nicer surface to do final finishing on once you peel it off. Work in a warm area, too... working when it's cool means you'll be using more resin to get it to wet out the plies. Use your squeegee. Epoxy resin is heavy!Oscar ZunigaSan Antonio, TXmailto: taildrags@hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________Date: Sat, 15 Dec 2007 10:25:35 -0800 (PST)

Original Posted By: Oscar Zuniga
Oscar,Nice pics, looks nice and lightweight. To quote a great designer/aviator "if you throw it up in the air and it comes back down, don't put it on your airplane". Stippling and squeeging out as much resin as possible thru the peel ply works wonders for keeping the laminate lightweight, using paper towels or rags to sop-up/wipe off the excess resin you can work out thru the peel ply.. At Boeing composites and Bigboys, they put down a peel ply, then a perforated teflon film, then a "baby blanket" (the polyester stuff quilts are filled with), then vacuum bag, put it autoclave under 4-5 atmospheres pressure. This squeezes out the absolute most excess resin out of the laminate. Physical testing indicates about 38% resin content maximizes the laminates properties without being too poor in resin content. Without autoclave pressure, it's impossible for a homebuilder to get the laminate too resin poor, it's always gonna be a little resin rich. Once you get over 40% resin content you contribute nothing to the laminates physical properties, the props actually start to decline and you're only adding more weight to the plane.Gordon ----- Original Message -----

Original Posted By: "MF"
Fiberglass cowlings? Why not use metal? It's light, simple,looks "antiquey", and there's no exposure to nastychemicals. The cowling I made for my Micro Mong is allsimple conicals except for the upper corners of the nosebowl, which I cut out of a stainless steel salad bowl. Ifany of you want photos, drop me an email and I'll send themto you. This airplane hasn't flown yet, so I'd keep my mouthshut if I hadn't heard of so many other builders doingsimilar things successfully.Larry the Micro Mong guyPS. I really don't have anything against 'glass, if you liketo mess with that kind of stuff, but there are ways to do itin metal that are not hard or time consuming, contrary torumor.________________________________________________________________________________Subject: Pietenpol-List: Model A engine

Original Posted By: Oscar Zuniga
Hi all,I'm new to the forum with some Model A engine questions. I saw somewhere on the internet a couple of recommended Model A engine books butcan't remember where I saw the posting. Any guesses?I live in Minnesota, any recommendations as to where to find a good core motor?Thanks,MattRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________