Original Posted By: "Warren D. Shoun"
> I don't have a good answer for that one Richard. Each "aircraft">vendor in the homebuilt market seems to attach different legalese to>their products. Some other folks won't even sell to you if you mention>that the material is going in a "homebuilt airplane". It seems to me>that all I can do is select the best material for each job; make each>piece to impossibly high standards and keep a journal and photo album>for my own education and entertainment....This is supposed to be fun!!!>>Warren.>How true! Would Bernard Pietenpol have gotten so caught up in the"certified aircraft" mumbo/jumbo? I think not! Good quality is what youare looking for. And since your life depends on it, better make sure it isgreat quality, not just good. But just because it has "papers" does not, initself, make it better. Benard used engines out of CARS! I am sure lots ofpeople thought he was crazy. If you want everything to be certified youbetter put in an aircraft engine, use aircraft wheels, etc, etc. In the endyou won't REALLY have a Pietenpol! If you take this thinking a littlefarther, then you aren't qualified to even be working on an airplane unlessyou are an A&P. Better just buy a factory airplane!You don't have to have materials documented as "certified aircraft" forinsurance or sale of a homebuilt but it MAY help. Good records on parts (bethey genuine "aircraft" or not) is always nice but not required. Perhapssomeone could supply specifics on the insurance: i.e. what insurancecompanies require it and exactly what do they require? Does it get lowerrates? Is this only for structural components? Etc. Or was this justreferring to the parts suppliers insurance if someone were to go after themfor bad parts?For what it is worth, Pete Bowers recommended door skins in his Flybabyplans and noted that the plywood for the fuselage has very low stresses(grossly over built). Given the similarity of construction I would say thesame applies to the Pietenpol (but have to admit I haven't analyzed it).Apparently door skins were readily available at that time. I lookedseriously at luan lumberyard plywood (called underlayment) but didn't buildthe plane. Underlayment needs to be free of voids so at least in thatregard it is what is needed for aircraft. I did some soak tests on the gluethat came out ok: no delamination. I cut up some and found no voids in thecore. It is only three ply so it is noticably weaker than aircraft materialwith 5 plies as someone noted in their testing. Another thing to watch outfor on lumber yard plywood: often the outer plys are VERY thin and theinner ply is very thick. I would avoid this type. Anyone have any realdata or experience with any of this? Strength of luan compared to birch? Iseem to remember them being about the same but it has been a long time.Other than one person breaking some test samples, no one has given muchsolid information. Most of the remarks seem to be just emotional responses. Sure some material will be stronger than others, but is the extra strengthneeded? I would also be interested in finding a supply of thinner plywood(haven't checked out the web site given yet). Most of the lumber yardmaterial is thicker than needed for ribs (the original question) and seemsto be more suitable for the fuselage.In the end, each person must make his own determination of suitabilty forthe construction materials for himself. Buying aircraft plywood does makethat easier by providing consistency.Jim________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: michael list
Jim Skinner wrote:> >> For what it is worth, Pete Bowers recommended door skins in his Flybaby> plans and noted that the plywood for the fuselage has very low stresses> (grossly over built). Jim,I sent Richard a reply to his question on the $14/sheet plywood andadvised him to stay away from it based on my experience using it in akayak. In a stressed area the skins pulled off the endgrain, and thiswas just during the building process! As you mention, this stuff iscalled both luan and doorskin, which has a thick core of endgrainmaterial with two thin face sheets. I don't think this is the samematerial as Pete Bowers "doorskin", which was probably a European gradeof thin plywood. Play it safe, get the aircraft grade stuff, you won'tbe sorry.Mike List________________________________________________________________________________
Jim Skinner wrote:> >> For what it is worth, Pete Bowers recommended door skins in his Flybaby> plans and noted that the plywood for the fuselage has very low stresses> (grossly over built). Jim,I sent Richard a reply to his question on the $14/sheet plywood andadvised him to stay away from it based on my experience using it in akayak. In a stressed area the skins pulled off the endgrain, and thiswas just during the building process! As you mention, this stuff iscalled both luan and doorskin, which has a thick core of endgrainmaterial with two thin face sheets. I don't think this is the samematerial as Pete Bowers "doorskin", which was probably a European gradeof thin plywood. Play it safe, get the aircraft grade stuff, you won'tbe sorry.Mike List________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: Ed0248(at)aol.com
>> I don't have a good answer for that one Richard. Each "aircraft">>vendor in the homebuilt market seems to attach different legalese to>>their products. Some other folks won't even sell to you if you mention>>that the material is going in a "homebuilt airplane". It seems to me>>that all I can do is select the best material for each job; make each>>piece to impossibly high standards and keep a journal and photo album>>for my own education and entertainment....This is supposed to be fun!!!>>>>Warren.>>>How true! Would Bernard Pietenpol have gotten so caught up in the>"certified aircraft" mumbo/jumbo? I think not! Good quality is what you>are looking for. And since your life depends on it, better make sure it is>great quality, not just good. But just because it has "papers" does not, in>itself, make it better. Benard used engines out of CARS! I am sure lots of>people thought he was crazy. If you want everything to be certified you>better put in an aircraft engine, use aircraft wheels, etc, etc. In the end>you won't REALLY have a Pietenpol! If you take this thinking a little>farther, then you aren't qualified to even be working on an airplane unless>you are an A&P. Better just buy a factory airplane!>>You don't have to have materials documented as "certified aircraft" for>insurance or sale of a homebuilt but it MAY help. Good records on parts (be>they genuine "aircraft" or not) is always nice but not required. Perhaps>someone could supply specifics on the insurance: i.e. what insurance>companies require it and exactly what do they require? Does it get lower>rates? Is this only for structural components? Etc. Or was this just>referring to the parts suppliers insurance if someone were to go after them>for bad parts?>>For what it is worth, Pete Bowers recommended door skins in his Flybaby>plans and noted that the plywood for the fuselage has very low stresses>(grossly over built). Given the similarity of construction I would say the>same applies to the Pietenpol (but have to admit I haven't analyzed it).>Apparently door skins were readily available at that time. I looked>seriously at luan lumberyard plywood (called underlayment) but didn't build>the plane. Underlayment needs to be free of voids so at least in that>regard it is what is needed for aircraft. I did some soak tests on the glue>that came out ok: no delamination. I cut up some and found no voids in the>core. It is only three ply so it is noticably weaker than aircraft material>with 5 plies as someone noted in their testing. Another thing to watch out>for on lumber yard plywood: often the outer plys are VERY thin and the>inner ply is very thick. I would avoid this type. Anyone have any real>data or experience with any of this? Strength of luan compared to birch? I>seem to remember them being about the same but it has been a long time.>Other than one person breaking some test samples, no one has given much>solid information. Most of the remarks seem to be just emotional responses. >>Sure some material will be stronger than others, but is the extra strength>needed? I would also be interested in finding a supply of thinner plywood>(haven't checked out the web site given yet). Most of the lumber yard>material is thicker than needed for ribs (the original question) and seems>to be more suitable for the fuselage.>>In the end, each person must make his own determination of suitabilty for>the construction materials for himself. Buying aircraft plywood does make>that easier by providing consistency.>>Jim>>Right on Jim, was trying to come up with a diplomatic to say it. Agree withyou 100%. Also wanted to thank you guys for all the neat engine info.________________________________________________________________________________
>> I don't have a good answer for that one Richard. Each "aircraft">>vendor in the homebuilt market seems to attach different legalese to>>their products. Some other folks won't even sell to you if you mention>>that the material is going in a "homebuilt airplane". It seems to me>>that all I can do is select the best material for each job; make each>>piece to impossibly high standards and keep a journal and photo album>>for my own education and entertainment....This is supposed to be fun!!!>>>>Warren.>>>How true! Would Bernard Pietenpol have gotten so caught up in the>"certified aircraft" mumbo/jumbo? I think not! Good quality is what you>are looking for. And since your life depends on it, better make sure it is>great quality, not just good. But just because it has "papers" does not, in>itself, make it better. Benard used engines out of CARS! I am sure lots of>people thought he was crazy. If you want everything to be certified you>better put in an aircraft engine, use aircraft wheels, etc, etc. In the end>you won't REALLY have a Pietenpol! If you take this thinking a little>farther, then you aren't qualified to even be working on an airplane unless>you are an A&P. Better just buy a factory airplane!>>You don't have to have materials documented as "certified aircraft" for>insurance or sale of a homebuilt but it MAY help. Good records on parts (be>they genuine "aircraft" or not) is always nice but not required. Perhaps>someone could supply specifics on the insurance: i.e. what insurance>companies require it and exactly what do they require? Does it get lower>rates? Is this only for structural components? Etc. Or was this just>referring to the parts suppliers insurance if someone were to go after them>for bad parts?>>For what it is worth, Pete Bowers recommended door skins in his Flybaby>plans and noted that the plywood for the fuselage has very low stresses>(grossly over built). Given the similarity of construction I would say the>same applies to the Pietenpol (but have to admit I haven't analyzed it).>Apparently door skins were readily available at that time. I looked>seriously at luan lumberyard plywood (called underlayment) but didn't build>the plane. Underlayment needs to be free of voids so at least in that>regard it is what is needed for aircraft. I did some soak tests on the glue>that came out ok: no delamination. I cut up some and found no voids in the>core. It is only three ply so it is noticably weaker than aircraft material>with 5 plies as someone noted in their testing. Another thing to watch out>for on lumber yard plywood: often the outer plys are VERY thin and the>inner ply is very thick. I would avoid this type. Anyone have any real>data or experience with any of this? Strength of luan compared to birch? I>seem to remember them being about the same but it has been a long time.>Other than one person breaking some test samples, no one has given much>solid information. Most of the remarks seem to be just emotional responses. >>Sure some material will be stronger than others, but is the extra strength>needed? I would also be interested in finding a supply of thinner plywood>(haven't checked out the web site given yet). Most of the lumber yard>material is thicker than needed for ribs (the original question) and seems>to be more suitable for the fuselage.>>In the end, each person must make his own determination of suitabilty for>the construction materials for himself. Buying aircraft plywood does make>that easier by providing consistency.>>Jim>>Right on Jim, was trying to come up with a diplomatic to say it. Agree withyou 100%. Also wanted to thank you guys for all the neat engine info.________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: Graham Hansen
Regarding plywood, has anyone checked into Hobby Shop birch plywood? Here inthe Memphis area at least two of the local "Building Supply" houses havesheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looksinteresting for gussets, etc.________________________________________________________________________________
Regarding plywood, has anyone checked into Hobby Shop birch plywood? Here inthe Memphis area at least two of the local "Building Supply" houses havesheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looksinteresting for gussets, etc.________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: michael list
Ed0248(at)aol.com wrote:> > Regarding plywood, has anyone checked into Hobby Shop birch plywood? Here in> the Memphis area at least two of the local "Building Supply" houses have> sheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looks> interesting for gussets, etc.Ed,I have seen some good looking 1/16 birch plywood in the local modelshops, too, and it looks fine for rib gussets and other small pieces. Cut some up before you use it and make sure you don't have any voids. The cost here is about the same as if you ordered it by mail, but itsure is nice to have it close at hand.Mike List________________________________________________________________________________
Ed0248(at)aol.com wrote:> > Regarding plywood, has anyone checked into Hobby Shop birch plywood? Here in> the Memphis area at least two of the local "Building Supply" houses have> sheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looks> interesting for gussets, etc.Ed,I have seen some good looking 1/16 birch plywood in the local modelshops, too, and it looks fine for rib gussets and other small pieces. Cut some up before you use it and make sure you don't have any voids. The cost here is about the same as if you ordered it by mail, but itsure is nice to have it close at hand.Mike List________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: "Warren D. Shoun"
I've read the comments over the past few weeks with interest concerning the useofcertified vs. non certified plywood for use on Piet projects. In 1939 Aeronca usedcardboard for their rib gussets so I don't see a problem using non-certifiedplywood.Some Gee Wiz Info: Bernard Pietenpol used oatmeal boxes for the leading edges(upper surface covering) on some of the airplanes he built.michael list wrote:> Ed0248(at)aol.com wrote:> >> > Regarding plywood, has anyone checked into Hobby Shop birch plywood? Herein> > the Memphis area at least two of the local "Building Supply" houses have> > sheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looks> > interesting for gussets, etc.> Ed,> I have seen some good looking 1/16 birch plywood in the local model> shops, too, and it looks fine for rib gussets and other small pieces.> Cut some up before you use it and make sure you don't have any voids.> The cost here is about the same as if you ordered it by mail, but it> sure is nice to have it close at hand.> Mike List--David B.Schober, CPEInstructor, Aviation MaintenanceFairmont State CollegeNational Aerospace Education CenterRt. 3 Box 13Bridgeport, WV 26330-9503(304) 842-8300________________________________________________________________________________
I've read the comments over the past few weeks with interest concerning the useofcertified vs. non certified plywood for use on Piet projects. In 1939 Aeronca usedcardboard for their rib gussets so I don't see a problem using non-certifiedplywood.Some Gee Wiz Info: Bernard Pietenpol used oatmeal boxes for the leading edges(upper surface covering) on some of the airplanes he built.michael list wrote:> Ed0248(at)aol.com wrote:> >> > Regarding plywood, has anyone checked into Hobby Shop birch plywood? Herein> > the Memphis area at least two of the local "Building Supply" houses have> > sheets of modeling plywood up to 3/32" in sheets up to 2'x4". Sure looks> > interesting for gussets, etc.> Ed,> I have seen some good looking 1/16 birch plywood in the local model> shops, too, and it looks fine for rib gussets and other small pieces.> Cut some up before you use it and make sure you don't have any voids.> The cost here is about the same as if you ordered it by mail, but it> sure is nice to have it close at hand.> Mike List--David B.Schober, CPEInstructor, Aviation MaintenanceFairmont State CollegeNational Aerospace Education CenterRt. 3 Box 13Bridgeport, WV 26330-9503(304) 842-8300________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: "Sayre, William G"
> Hi David: I contributed a number of comments to this discussion earlier, and my interestwas in pointing one of our guys away from using luan door skins that, unless carefullysealed early on, will begin to separate just from ambient moisture in the air.Wehave probably all seen this type of bulge on cheap hollow-core doors---not goodairplane material. The material that I chose is clearly not certified, however,from my own rather simple bench tests, it is in fact stronger to impact, bendingandtorsional loads than the "certified" stuff, and it costs less and it is availablefromboth large importers and from Hobby shops and specialty shops for tool & die makersinsmall sizes. If you do build a Pietenpol from Quaker Oats boxes, have your next of kin letusknow how it turns out....he said tongue in cheek.Warren________________________________________________________________________________
> Hi David: I contributed a number of comments to this discussion earlier, and my interestwas in pointing one of our guys away from using luan door skins that, unless carefullysealed early on, will begin to separate just from ambient moisture in the air.Wehave probably all seen this type of bulge on cheap hollow-core doors---not goodairplane material. The material that I chose is clearly not certified, however,from my own rather simple bench tests, it is in fact stronger to impact, bendingandtorsional loads than the "certified" stuff, and it costs less and it is availablefromboth large importers and from Hobby shops and specialty shops for tool & die makersinsmall sizes. If you do build a Pietenpol from Quaker Oats boxes, have your next of kin letusknow how it turns out....he said tongue in cheek.Warren________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: "Warren D. Shoun"
Among other comments, Warren D. Shoun said:> The material that I chose is clearly not certified, however,> from my own rather simple bench tests, it is in fact stronger to impact,bending and> torsional loads than the "certified" stuff, and it costs less and it isavailable from> both large importers and from Hobby shops and specialty shops for tool &die makers in> small sizes.Maybe I missed a post that explained this, but just what is it you'reusing?Do you have specs, brand name, or what to ask for? The stuff I've seenin hobby shops appears to be more or less standard aircraft ply, repackagedunder some hobby marketer's name, and I have no idea what tool and diemakers use. I would have guessed Baltic Birch, but that is notoriouslyprone to delamination when in a moist environment.What importers stock this stuff?Many thanks.Owen Davies________________________________________________________________________________
Among other comments, Warren D. Shoun said:> The material that I chose is clearly not certified, however,> from my own rather simple bench tests, it is in fact stronger to impact,bending and> torsional loads than the "certified" stuff, and it costs less and it isavailable from> both large importers and from Hobby shops and specialty shops for tool &die makers in> small sizes.Maybe I missed a post that explained this, but just what is it you'reusing?Do you have specs, brand name, or what to ask for? The stuff I've seenin hobby shops appears to be more or less standard aircraft ply, repackagedunder some hobby marketer's name, and I have no idea what tool and diemakers use. I would have guessed Baltic Birch, but that is notoriouslyprone to delamination when in a moist environment.What importers stock this stuff?Many thanks.Owen Davies________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: Owen Davies
Hi Owen: Me thinks we may be making too much of a good thing here.... Anyway, what I have decided to use is sold as "Ultra thin Finland birchplywood". The manufacturer certifies it for uniform glue spreading and veneerthickness. Both faces and interior plys are free of knots and voids. IT IS NOT CERTIFIED FOR AIRCRAFT USE. However, for example, the aircraft1/8" stuff is 3 ply and this stuff is 5 ply, and it sells for $2.16 per sq.foot in 61" X 61" sheets. The importer I use is that is near where I live. ANDERSON INTERNATIONAL TRADING 1171 N. Tustin Avenue Anaheim, Ca. 92807-1736(714) 666-8183 1-800-454-6270 Fax (714) 666-0709 They also have a web page at : www.aitwood.com which is veryinteresting. If you go to the web page, look at the ultra-thin plywoodsection as well as the other listings. You can also buy 1/8" 3 ply Birch Plywood from these folks for as littleas 55 cents to 79 cents per sq. ft. I may well be "over-engineering" the gusset plates here. As a purelypersonal preference, I'm not sure that I want to fly something that iscompletely supplied by the low bidder.Best Regards, Warren________________________________________________________________________________
Hi Owen: Me thinks we may be making too much of a good thing here.... Anyway, what I have decided to use is sold as "Ultra thin Finland birchplywood". The manufacturer certifies it for uniform glue spreading and veneerthickness. Both faces and interior plys are free of knots and voids. IT IS NOT CERTIFIED FOR AIRCRAFT USE. However, for example, the aircraft1/8" stuff is 3 ply and this stuff is 5 ply, and it sells for $2.16 per sq.foot in 61" X 61" sheets. The importer I use is that is near where I live. ANDERSON INTERNATIONAL TRADING 1171 N. Tustin Avenue Anaheim, Ca. 92807-1736(714) 666-8183 1-800-454-6270 Fax (714) 666-0709 They also have a web page at : www.aitwood.com which is veryinteresting. If you go to the web page, look at the ultra-thin plywoodsection as well as the other listings. You can also buy 1/8" 3 ply Birch Plywood from these folks for as littleas 55 cents to 79 cents per sq. ft. I may well be "over-engineering" the gusset plates here. As a purelypersonal preference, I'm not sure that I want to fly something that iscompletely supplied by the low bidder.Best Regards, Warren________________________________________________________________________________
Pietenpol-List: Re: Certification / Insurance and plywood
Original Posted By: michael list
Many thanks for the info. I'll take a look at their Web site.Good luck with your project.Owen________________________________________________________________________________
Many thanks for the info. I'll take a look at their Web site.Good luck with your project.Owen________________________________________________________________________________