Pietenpol-List: woods and woodworking
Posted: Sat Nov 17, 2001 12:55 pm
Original Posted By: "Jeff Hill"
Hello, low 'n' slow fliers (except Corky, up there on oxygen);My experience has been pretty much the same as what the other comments have been. I started out with the EAA "Wood Book" and the AC information on selection and application of various woods, plus the outstanding series of articles in Sport Aviation last year. I think Ron Alexander wrote them. Anyway, that series of articles is like a compilation of 'dos and donts' from the other sources, but includes excellent illustrations that make it very clear what to look for as far as pitch pockets, brashness, grain slope, all of that. I would highly recommend that series of articles to anybody building with wood.In my area (up here with "Mac in Oregon") I can walk into a building supply and find long, straight, clear Douglas fir or "hem fir" (hemlock), along with some decent pine, anytime. But what I've found is that if I can go to one of the places that salvages building materials from demolished buildings, I can find some truly fine stuff. In the old days when they built using rough-sawn dimension lumber for framing, they used some really prime stuff up here because it was so easy to get. So I can buy a long, rough, old (as in cured and dried) beam, rafter, joist, or other framing member and plane the rough faces off and square it up in the jointer to see what I've got. From that, I can rip or plane some really nice stuff. Cost is just unbelievably cheap. Now I'm talking about Douglas fir, so you guys who don't care to work with fir- sorry. But as mentioned above- it is also common to find good hemlock and red fir at prices just a bit more than rough framing lumber. I simply cannot justify buying aircraft spruce when I can buy lumber with equal or better strength and meeting all the aircraft wood grading standards, for a fraction of the cost. Sure, I need a planer and a table saw to get it into shape, and I have to grade around nail holes and knots sometimes, but I can buy all the dimension lumber needed for a Pietenpol -spars included- for probably $250. Less than that or even free, if I scrounge it from somebody who's tearing down a building. And there are perfectly acceptable methods of scarfing wood members, both structural and non-structural, so the search for seamless long spar material doesn't have to burrow deep into your savings. Use the right structural glue, the right jointing methods, the right clamps and tools, and you have very airworthy structures. It isn't rocket science... and it smells a lot better than that nasty old welding smoke and carborundum dust ;o)The prototype M-19 "Flying Squirrel" was built using sassafras for the wood structure. Look in the old AC wood books and you might find it; perfectly satisfactory. Are these "alternate woods" somehow questionable or unsuitable for aircraft use? No, not necessarily. The reason every wood isn't listed in the AC manuals is that they are only concerned with the most widely used, easily graded, and most available. There are regional or scarcer woods that are very suitable for our needs, but they take a little more investigation to find or to apply. When you're faced with spending several thousand dollars for a smallish bundle of wood, you start scratching your head wondering why you can't use something a little more reasonable. You can... provided it gives you the same strength as the select aircraft lumber.As far as tools, the table saw is -to me- essential. It makes so many tasks so easy! And yes, nothing is quite as maddening as setting up a saw and passing a piece of wood first one side then flipping it over to the other, and finding you now have a tapered piece of wood. It _has_ to be square or you'll be frustrating your every attempt to build a square and straight ship. If you can't afford a table saw, or don't have room for one, hook up with a buddy who does (or someone in your EAA chapter or craft guild). That's what I did.Oscar ZunigaMedford, Oregonmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________
Hello, low 'n' slow fliers (except Corky, up there on oxygen);My experience has been pretty much the same as what the other comments have been. I started out with the EAA "Wood Book" and the AC information on selection and application of various woods, plus the outstanding series of articles in Sport Aviation last year. I think Ron Alexander wrote them. Anyway, that series of articles is like a compilation of 'dos and donts' from the other sources, but includes excellent illustrations that make it very clear what to look for as far as pitch pockets, brashness, grain slope, all of that. I would highly recommend that series of articles to anybody building with wood.In my area (up here with "Mac in Oregon") I can walk into a building supply and find long, straight, clear Douglas fir or "hem fir" (hemlock), along with some decent pine, anytime. But what I've found is that if I can go to one of the places that salvages building materials from demolished buildings, I can find some truly fine stuff. In the old days when they built using rough-sawn dimension lumber for framing, they used some really prime stuff up here because it was so easy to get. So I can buy a long, rough, old (as in cured and dried) beam, rafter, joist, or other framing member and plane the rough faces off and square it up in the jointer to see what I've got. From that, I can rip or plane some really nice stuff. Cost is just unbelievably cheap. Now I'm talking about Douglas fir, so you guys who don't care to work with fir- sorry. But as mentioned above- it is also common to find good hemlock and red fir at prices just a bit more than rough framing lumber. I simply cannot justify buying aircraft spruce when I can buy lumber with equal or better strength and meeting all the aircraft wood grading standards, for a fraction of the cost. Sure, I need a planer and a table saw to get it into shape, and I have to grade around nail holes and knots sometimes, but I can buy all the dimension lumber needed for a Pietenpol -spars included- for probably $250. Less than that or even free, if I scrounge it from somebody who's tearing down a building. And there are perfectly acceptable methods of scarfing wood members, both structural and non-structural, so the search for seamless long spar material doesn't have to burrow deep into your savings. Use the right structural glue, the right jointing methods, the right clamps and tools, and you have very airworthy structures. It isn't rocket science... and it smells a lot better than that nasty old welding smoke and carborundum dust ;o)The prototype M-19 "Flying Squirrel" was built using sassafras for the wood structure. Look in the old AC wood books and you might find it; perfectly satisfactory. Are these "alternate woods" somehow questionable or unsuitable for aircraft use? No, not necessarily. The reason every wood isn't listed in the AC manuals is that they are only concerned with the most widely used, easily graded, and most available. There are regional or scarcer woods that are very suitable for our needs, but they take a little more investigation to find or to apply. When you're faced with spending several thousand dollars for a smallish bundle of wood, you start scratching your head wondering why you can't use something a little more reasonable. You can... provided it gives you the same strength as the select aircraft lumber.As far as tools, the table saw is -to me- essential. It makes so many tasks so easy! And yes, nothing is quite as maddening as setting up a saw and passing a piece of wood first one side then flipping it over to the other, and finding you now have a tapered piece of wood. It _has_ to be square or you'll be frustrating your every attempt to build a square and straight ship. If you can't afford a table saw, or don't have room for one, hook up with a buddy who does (or someone in your EAA chapter or craft guild). That's what I did.Oscar ZunigaMedford, Oregonmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________