---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Sun 03/20/05: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:46 AM - BALTIC BIRCH--be careful (rhartwig11@juno.com) 2. 12:56 PM - Re: BALTIC BIRCH--be careful (Galen Hutcheson) 3. 02:47 PM - "convert" program (walt evans) 4. 03:27 PM - Re: "convert" program (owner-pietenpol-list-server@matronics.com) 5. 05:12 PM - C-90 Piet (clawler@ptd.net) 6. 09:26 PM - Re: "convert" program (Doyle Combs) 7. 10:34 PM - Re: "convert" program (Javier Cruz) ________________________________ Message 1 _____________________________________ Time: 10:46:58 AM PST US Subject: Pietenpol-List: BALTIC BIRCH--be careful From: rhartwig11@juno.com I would suggest using caution if you are buying Baltic Birch for aircraft building. The only Baltic Birch I have seen is interior grade and I use a lot of Baltic Birch for cabinet making. I am not saying that there is no such thing as Baltic Birch glued with waterproof glue, but any that I have soaked in water has peeled apart. Just to make sure I was not blowing smoke on this subject, I took a break from writing this and sliced off a 1/16 inch strip from the edge of a beautiful sheet of 5/8 inch Baltic Birch. I placed it in a pan of boiling water. Within 3 minutes the laminations started popping apart. You can boil aircraft or marine ply like this for an hour and it will not come apart. The only non-aircraft plywood that I would recommend is 1088 spec. marine ply. or good modeling ply such as Sig brand which is used in the model airplane business. There are probably other good plys, but I would not use them unless I performed boiling water tests on them. The difference between aircraft/marine plywoods and other plywoods is not only in the glues used to laminate them, but in the defects, patches and voids that are allowed in the face veneers and interior laminations. I am assuming when Doc said "A/C" plywood he meant "aircraft" plywood. If you ask for "A/C" plywood at the lumberyard it just means that the plywood has a face veneer on one side this is "A" (relatively defect free/or plugged) and a lesser "C" quality veneer on the other side--not the sort of ply you would want to use for primary aircraft structure. When grading boards it is easy to see the lines caused by the annular rings and to determine if they run from end to end (or 1" in 15"). There is also grain running at 90 degrees to the annular rings. The only way you can check that for run out is to cut a few inches off each end of the board and split it with a chisel 90 degrees to the annular rings and then measure for run out. I believe (without checking the book) run out should be no more than one inch in 15 inches. Get a good book on grading aircraft wood if you are not using certified woods. Dick Hartwig ________________________________ Message 2 _____________________________________ Time: 12:56:36 PM PST US s=s1024; d=yahoo.com; b=tgbPw+TNEc8iA/Oji1K+K/Kje21RU18xI676q9tdjQH9azceGnQPUMrQcrcgss6sQV9/Y9CdrnZ6hhfI2Elrlm3u0QGpduulbIoEWUta1XK1qoz9FtCKgpLr/F2d6SovgfQgHh2tSg4QVyQODQrUOAipMbT2f+oNiPrx4KUvPU0= ; From: Galen Hutcheson Subject: Re: Pietenpol-List: BALTIC BIRCH--be careful --> Pietenpol-List message posted by: Galen Hutcheson I did mean A/C to stand for "Aircraft." I do know of several airplanes flying successfully with baltic birch plywood for gussetts. I think the best test to see if a material is adequate would be one designed to simulate actual conditions under which it will be used. I have subjected baltic birch test pieces under rather high heat and high humidity with no major problems. I protected the wood with polyurethane varnish and allowed it to cure for at least one week before the tests. I tried to simulate a test that would be more likely to reflect actual conditions. Sunlight is another stressor that needs to be tested, which I did. Of course, my tests may not pass those of professional engineers, but I am satisified with the results. I'm sure that different manufacturing companies produce different qualities of plywood, so it would be difficult to make generalized statements. The safest bet, of course, would be to buy certified aircraft quality products...provided you have the budget to do so. Safety is the key point, so any non-certified materials must be tested (under realistic condidions) to see if they are safe materials to use. Doc --- rhartwig11@juno.com wrote: > I would suggest using caution if you are buying > Baltic Birch for aircraft > building. The only Baltic Birch I have seen is > interior grade and I use > a lot of Baltic Birch for cabinet making. I am not > saying that there is > no such thing as Baltic Birch glued with waterproof > glue, but any that I > have soaked in water has peeled apart. Just to make > sure I was not > blowing smoke on this subject, I took a break from > writing this and > sliced off a 1/16 inch strip from the edge of a > beautiful sheet of 5/8 > inch Baltic Birch. I placed it in a pan of boiling > water. Within 3 > minutes the laminations started popping apart. You > can boil aircraft or > marine ply like this for an hour and it will not > come apart. The only > non-aircraft plywood that I would recommend is 1088 > spec. marine ply. or > good modeling ply such as Sig brand which is used in > the model airplane > business. There are probably other good plys, but I > would not use them > unless I performed boiling water tests on them. > > The difference between aircraft/marine plywoods and > other plywoods is not > only in the glues used to laminate them, but in the > defects, patches and > voids that are allowed in the face veneers and > interior laminations. I > am assuming when Doc said "A/C" plywood he meant > "aircraft" plywood. If > you ask for "A/C" plywood at the lumberyard it just > means that the > plywood has a face veneer on one side this is "A" > (relatively defect > free/or plugged) and a lesser "C" quality veneer on > the other side--not > the sort of ply you would want to use for primary > aircraft structure. > > When grading boards it is easy to see the lines > caused by the annular > rings and to determine if they run from end to end > (or 1" in 15"). There > is also grain running at 90 degrees to the annular > rings. The only way > you can check that for run out is to cut a few > inches off each end of > the board and split it with a chisel 90 degrees to > the annular rings and > then measure for run out. I believe (without > checking the book) run out > should be no more than one inch in 15 inches. Get a > good book on grading > aircraft wood if you are not using certified woods. > Dick Hartwig ________________________________ Message 3 _____________________________________ Time: 02:47:03 PM PST US From: "walt evans" Subject: Pietenpol-List: "convert" program A year or so ago I offered a program to any one who wanted it. It's called "convert" and it converts anything to anything. Any volume amounts, any weight amounts, angles,speed, temp, torque, force, blah, blah, blah. Simple to use, even the engineers got a kick out of it. Any body that doesn't have it wants it, just post to the group, and I'll send it to you directly. It's about 1/2 meg, and don't want to clog up the group. walt evans NX140DL ________________________________ Message 4 _____________________________________ Time: 03:27:51 PM PST US From: owner-pietenpol-list-server@matronics.com 279 274 6 From: "Jake Crause" Subject: RE: Pietenpol-List: "convert" program --> Pietenpol-List message posted by: "Jake Crause" Walt - I'll take a copy. Thanks. Jake do not archive -----Original Message----- From: walt evans [mailto:wbeevans@verizon.net] Subject: Pietenpol-List: "convert" program A year or so ago I offered a program to any one who wanted it. It's called "convert" and it converts anything to anything. Any volume amounts, any weight amounts, angles,speed, temp, torque, force, blah, blah, blah. Simple to use, even the engineers got a kick out of it. Any body that doesn't have it wants it, just post to the group, and I'll send it to you directly. It's about 1/2 meg, and don't want to clog up the group. walt evans NX140DL Walt Ill take a copy. Thanks. Jake do not archive

-----Original Message----- From: walt evans [mailto:wbeevans@verizon.net] PM Subject: Pietenpol-List: convert program

A year or so ago I offered a program to any one who wanted it. It's called convert and it converts anything to anything. Any volume amounts, any weight amounts, angles,speed, temp, torque, force, blah, blah, blah. Simple to use, even the engineers got a kick out of it.

Any body that doesn't have it wants it, just post to the group, and I'll send it to you directly.

It's about 1/2 meg, and don't want to clog up the group.

walt evans NX140DL ________________________________ Message 5 _____________________________________ Time: 05:12:48 PM PST US From: clawler@ptd.net Subject: Pietenpol-List: C-90 Piet --> Pietenpol-List message posted by: clawler@ptd.net I just ran up my engine for the first time today. C-90 with a 72CK42 Sensenich prop. Got 2200 rpm with the plane tied down. Is this about what some of the rest of you are getting with a C-90? Got the engine from Don's Dream Machines. Runs real smooth. They recommend a 72WGK42. Do any of you know the difference? If both are about the same there is no point in buying another prop. Craig NX899CL ________________________________ Message 6 _____________________________________ Time: 09:26:49 PM PST US s=test1; d=earthlink.net; b=cLTDHBLxCiwh70d/4pr52sgefA8BvovLMo9TmIB1/bS8r5h6+J/SkqlBJdj91+qN; From: "Doyle Combs" Subject: Re: Pietenpol-List: "convert" program Walt, I would appreciate the convert program. Doyle Combs ----- Original Message ----- From: walt evans To: pietenpol-list@matronics.com Sent: Sunday, March 20, 2005 4:41 PM Subject: Pietenpol-List: "convert" program A year or so ago I offered a program to any one who wanted it. It's called "convert" and it converts anything to anything. Any volume amounts, any weight amounts, angles,speed, temp, torque, force, blah, blah, blah. Simple to use, even the engineers got a kick out of it. Any body that doesn't have it wants it, just post to the group, and I'll send it to you directly. It's about 1/2 meg, and don't want to clog up the group. walt evans NX140DL ________________________________ Message 7 _____________________________________ Time: 10:34:04 PM PST US From: Javier Cruz Subject: Re: Pietenpol-List: "convert" program If you can.. please add my e-mail Thanks Walt.. Do not archive