From: krnet-bounces+johnbou=speakeasy.net@mylist.net on behalf of krnet-request@mylist.net Sent: Saturday, October 18, 2003 12:00 PM To: krnet@mylist.net Subject: KRnet Digest, Vol 192, Issue 1 Send KRnet mailing list submissions to krnet@mylist.net To subscribe or unsubscribe via the World Wide Web, visit http://mylist.net/listinfo/krnet or, via email, send a message with subject or body 'help' to krnet-request@mylist.net You can reach the person managing the list at krnet-owner@mylist.net When replying, please edit your Subject line so it is more specific than "Re: Contents of KRnet digest..." Today's Topics: 1. Re: paint (Dan Heath) 2. Project for sale... half price day (Ron Freiberger) 3. Re: paint (Tim Brown) 4. Re: paint (Mark Jones) 5. fairings (Oscar Zuniga) 6. paint (Oscar Zuniga) 7. Corvair oil (William Clapp) 8. Re: paint (William Clapp) 9. Re: insurance (roger mitchell) 10. Re: paint (Timothy Bellville) 11. Re: paint (Mark Langford) ---------------------------------------------------------------------- Date: Fri, 17 Oct 2003 18:13:42 -0400 (Eastern Standard Time) From: "Dan Heath" To: Subject: Re: KR>paint Message-ID: <3F906996.000001.02736@Computer> References: <20031017134220.16208.qmail@web11006.mail.yahoo.com> Content-Type: Text/Plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: list Message: 1 Well, Mark, you just can't get away with anything. =0D =0D I have wondered for sometime, but never got around to asking, about paint= on places where the "sun don't shine". Is there a problem with heat seeking paint in those places. I think not, and I guess Mark decided the same.=20 Although, I have seen some colors right on top and it didn't seem to have catastrophic consequences. I am also planning on color on the bottom.=0D =0D N64KR=0D =0D Daniel R. Heath - Columbia, SC=0D =0D DanRH@KR-Builder.org=0D =0D See you in Mt. Vernon - 2004 - KR Gathering=0D =0D See our KR at http://KR-Builder.org - Click on the pic=0D See our EAA Chapter 242 at http://EAA242.org=0D =20From n56ml@hiwaay.net Fri Oct 17 17:01:15 2003 Received: from smtp3.knology.net ([24.214.63.14] helo=smtp2.knology.net) by lizard.esosoft.net with smtp (Exim 3.36 #1) id 1AAeWx-000DXZ-00 for krnet@mylist.net; Fri, 17 Oct 2003 17:01:15 -0700 Received: (qmail 32164 invoked from network); 18 Oct 2003 00:05:09 -0000 Received: from unknown (HELO basement) (24.214.88.148) by smtp3.knology.net with SMTP; 18 Oct 2003 00:05:09 -0000 Message-ID: <1dd501c3950b$c72cd990$1202a8c0@basement> From: "Mark Langford" To: "KR builders and pilots" References: <20031017134220.16208.qmail@web11006.mail.yahoo.com> <3F906996.000001.02736@Computer> Subject: Re: KR>paint Date: Fri, 17 Oct 2003 19:07:08 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-BeenThere: krnet@mylist.net X-Mailman-Version: 2.1b3 Precedence: list Reply-To: KR builders and pilots List-Id: KR builders and pilots List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Help: Y'all can just go ahead and call me stupid, but my airplane's gonna be red. Again, I'll say that when the plane is sitting on gear, there are no stresses on any composites, other than the Scotchply 3M gear legs. My wings are covered with two layers of carbon fiber (three on the leading edge), which you might remember, are supported by 3/8 to 1/2" of urethane foam, which is supported by an inner layer of fiberglass. So let's just say my composite skin gets up to Tg, the temperature at which the strength of the epoxy is significantly reduced. For Aeropoxy, that's 194 degrees F for layups cured at room temperature. It's normally good for something like 45,000 psi. I'd call "significant" something like 75%, but lets just be conservative and say that the strength is cut in half. Now it's down to ONLY 22,500 psi. But wait, I have a half inch layer of foam being supporting by another layer of fiberglass that's at least 30 degrees cooler (my inner skin). And don't forget, there is absolutely no external influence on this surface, other than gravity pulling down on something that weighs just about nothing. I actually called myself "post curing" my stub wings right after they were constructed, by parking the plane out in the sun one hot day that summer, shortly after construction. I taped (using clear tape) a Fluke 52 digital recording thermometer's thermocouple to the black, unpainted surface, and the best I can remember, the highest temperature I ever saw was 128 degrees F. Don't forget, it's "air-cooled", just sitting there! Given the rule of thumb that your Tg will be raised to 50 degrees over the post cure temp, I was probably wasting my time at that "low" temperature. So when is it going to see 194 degrees? Never. And what effect would it have if it DID see 194 degrees? None. And how much strength is required of the skin, just sitting there on the tarmac? Absolutely none. And how long does it take something as thin and massless as a .020" thick layer of carbon fiber layup to cool off with a 30 mph breeze blowing on it during takeoff? About 5 seconds. The few horror stories you hear about planes "melting" in the sun are referring to airplanes with composite parts such as spars and stressed skins supporting the load while parked. Neither of these apply to my plane. Sorry, but I have a bad habit of getting the facts, considering all aspects of the situation, and making my own decisions. It's gonna be red, and if y'all don't like it, you can just get over it... http://home.hiwaay.net/~langford/03101703m.jpg Mark Langford, Huntsville, AL N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford ------------------------------ Date: Fri, 17 Oct 2003 21:01:50 -0400 From: "Ron Freiberger" To: "KR Builders and Flyers" Cc: Subject: KR>Project for sale... half price day Message-ID: Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 2 I've decided to sell my KR2 project. You can see details at http://home.swfla.rr.com/ronmartha/ in the Ron'sKR2 directory. This aircraft was started as a stretch KR2 with 14 inches added aft, and 5 inches forward. Width is standard, and controls are set to allow single or dual operation. Spars are finished and wing parts ready to foam. Aluminum tanks <3> and set up for good CG control. See detailed description at KR2.rtf Lots of pictures, in a somewhat organized grouping. I've spent $11,317 somewhat wisely, and will sell for half price ($5653) until mid November. Then, if not sold, I will part it out on eBay when I get back to Florida in January. See $'s invested at KR INVEST.rtf If you want to see what I've built previously, see MY Planes.doc Ron Freiberger mailto: rfreiberger@swfla.rr.com ------------------------------ Date: Fri, 17 Oct 2003 18:48:39 -0700 (PDT) From: Tim Brown To: KR builders and pilots Subject: Re: KR>paint Message-ID: <20031018014839.63883.qmail@web40903.mail.yahoo.com> In-Reply-To: <1dd501c3950b$c72cd990$1202a8c0@basement> Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 Precedence: list Message: 3 YOU GO GUY!!!!!!!!!! > Sorry, but I have a bad habit of getting the > facts, considering all aspects > of the situation, and making my own decisions. > It's gonna be red, and if > y'all don't like it, you can just get over > it... > __________________________________ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com ------------------------------ Date: Fri, 17 Oct 2003 21:26:42 -0500 From: "Mark Jones" To: "KR builders and pilots" Subject: Re: KR>paint Message-ID: <004f01c3951f$452fef40$6401a8c0@wi.rr.com> References: <20031017134220.16208.qmail@web11006.mail.yahoo.com> <3F906996.000001.02736@Computer> <1dd501c3950b$c72cd990$1202a8c0@basement> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 4 Nice photo Mark....that red blends in real nice with the VW......I tend to agree with you, white is out and color is in!!! Your paint job looks fabulous. I just finished attaching all the piano hinges to my firewall and installing the cowl. I must say that the cowl fits like a glove. Now to start installing the baffling. Mark Jones (N886MJ) Wales, WI USA E-mail me at flykr2s@wi.rr.com Visit my KR-2S CorvAIRCRAFT web site at http://mywebpage.netscape.com/n886mj/homepage.html ----- Original Message ----- From: "Mark Langford" . It's gonna be red, and if > y'all don't like it, you can just get over it... > > http://home.hiwaay.net/~langford/03101703m.jpg > > ------------------------------ Date: Fri, 17 Oct 2003 21:57:32 -0500 From: "Oscar Zuniga" To: krnet@mylist.net Subject: KR>fairings Message-ID: Content-Type: text/plain; format=flowed MIME-Version: 1.0 Precedence: list Message: 5 DP asks- >Anyone have experience "dropping" a lip from the lower cowl >to let heat escape? No experience here whatsoever... just from what I've read about it and know from theory. What you have inside the engine cowling is air that has entered at a relatively high pressure and has gone through a set of cooling fins on the engine cylinders and heads, baffles, oil cooler, whatever- and has lost some of its pressure. The air on the underside of the airplane is at a high velocity, zipping by in the slipstream, and at a relatively higher pressure than the air inside the cowling. That difference in pressure tends to prevent the air from wanting to exit the lower lip of the cowling and enter the slipstream under the airplane. The small 'lip' on the trailing edge of the cowling air exit tends to add resistance to the slipstream (pressure loss), to allow the air inside the cowling to more easily exit. The pressure of the air inside the cowling has to be greater than the pressure outside for the air to exit, so we have to drop the pressure of the slipstream air by introducing the "lip" to add drag. As noted in many tech write-ups on engine installations, engine cooling is usually a major teething problem and folks have even found that air is tending to go up into the cowling through the "exit" opening on the bottom, so they make the opening even larger... which lowers the pressure of the airstream trying to exit... and hinders the cause. But don't try a 'lip' unless it's necessary due to high engine temps or other indications of insufficient airflow through the cowling. And if you're experimenting with a 'lip', make it something you can remove in case it doesn't work out after test flights. Some of this is "black magic" and we don't really have the answers ;op Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net _________________________________________________________________ Fast, faster, fastest: Upgrade to Cable or DSL today! https://broadband.msn.com ------------------------------ Date: Fri, 17 Oct 2003 22:04:19 -0500 From: "Oscar Zuniga" To: krnet@mylist.net Subject: KR>paint Message-ID: Content-Type: text/plain; format=flowed MIME-Version: 1.0 Precedence: list Message: 6 Netters; Mark Langford knows what he's doing. The critical temp for extruded polystyrene foam (blue Dow or pink Owens-Corning) is about 165F, a temperature that can be exceeded when a "KR of color" sits out on the ramp in the sun at your typical fly-in. However, urethane foam (polyisocyanurate or other) does not have this same critical temperature at which it loses its dimensional stability, and I believe Mark has used urethane foam for the majority of his construction. One of the main problems with polystyrene foam and the temperature limitation that indicates the use of predominately white paint is that the plane will develop a case of the "bulges", where bumps and blisters, and later sags and valleys, as well as ridges, develop as the plane's structure heats up into that temperature. These are the things that can lead to delamination of the fiberglass skins and also make the plane look plumb ugly. This is besides the thermal effects on the structural airframe epoxy and the fiberglass skin epoxy, both of which have their own problems but not like the polystyrene foam. What was it Virg always says, "build to the plans"? If you don't know what you're doing, paint it white and you'll be on the safe side... Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net _________________________________________________________________ Express yourself with MSN Messenger 6.0 -- download now! http://www.msnmessenger-download.com/tracking/reach_general ------------------------------ Date: Fri, 17 Oct 2003 23:18:04 -0400 From: "William Clapp" To: "KR builders and pilots" Subject: KR>Corvair oil Message-ID: <003001c39526$7267b180$0dfcd241@clapp> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: list Message: 7 After thinking about this oil cooler and filter situation on the Corvair = motor I think I have it figured out - Somewhat.. If I am wrong someone = let me know. I have a plate covering the accessory case - instead of = keeping the original pump/filter assy. I have oil leaving out of the = pump side(passenger side) through AN 6 fittings to a firewall mounted = filter (filter has bypass built in). From the filter we go to the = cooler and then return to the TOP hole of the cooler attachment on the = case. Previously I though it was to return to the bottom hole. I will = have an oil pressure sender mounted at the OUTPUT side of the cooler = before entering the case. This is the closest I think I can get to = galley pressure. I am hoping that I thought this through correctly = because I plan to drill my fitting hole into my plates this weekend and = measure for some hoses soon. Next question... Anybody have some firewall pictures with the Corvair = installation to see hou you routed cables - battery box installations - = ductwork - etc...? Hope to visit with Dean Cooper this weekend - a new KR face - sounds = very promising... Happy Building y'all..... Bill=20 ------------------------------ Date: Fri, 17 Oct 2003 23:24:27 -0400 From: "William Clapp" To: "KR builders and pilots" Subject: Re: KR>paint Message-ID: <003601c39527$56d26cc0$0dfcd241@clapp> References: Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 8 I remember a few years back of a bright yellow KR2 that a friend of my father owned. It was named "Tweety Bird". Later I believe he sold it and the built and RV4 that was also yellow and called "Tweety Bird II" I saw the RV in Oshkosh many years ago but it was the first all colored KR I had seen. He did this paint scheme mostly for safety sake. Yellow being almost as bright as strobe and such... I wonder what happened to it.. Bill ----- Original Message ----- From: Oscar Zuniga To: Sent: Friday, October 17, 2003 11:04 PM Subject: KR>paint > Netters; ------------------------------ Date: Sat, 18 Oct 2003 01:15:34 -0500 From: "roger mitchell" To: "KR builders and pilots" Subject: Re: KR>insurance Message-ID: References: <3.0.6.32.20031012211435.007f2100@pop.midwest.net> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: list Message: 9 I fired up my engine for the first time the other day,gp 2180 w/ rear = drive,on an run stand. hope to move to a/p in two mos. can you give more = info on insurance. ----- Original Message -----=20 From: larry flesner=20 To: KR builders and pilots=20 Sent: Sunday, October 12, 2003 9:14 PM Subject: KR>insurance There's a lot of information in here and the authur >, Scott Smith, is an agent and says that He was appionted by = Jeannette Rand >as the preferred agent for the KR2. >Paden Waldren +++++++++++++++++++++++++++++++++++++++++++++++++++++++=3D I've had my Tripacer insurance for 5 1/2 years through Scott "Sky" Smith and I'm now with the third insurance company. They are great people to work with but I recently tried to get insurance on the KR (liability only) and they coundn't find anyone that=20 would insure it. =20 Avemco said they would give me liability for about $1000 a year. I plan to get 3 months coverage just before my=20 first flight (soon) and then get a re-quote. I was "playing" on the runway today and bystanders said the tail was up on one run for 50 feet or more. I couldn't even tell it came up as it was tracking straight as an arrow and required little if any rudder input. Something to be said for my 8 foot wide gear and the 24 inch stretch on the fuselage. Larry Flesner _______________________________________________ see KRnet list details at http://www.krnet.org/instructions.html ------------------------------ Date: Sat, 18 Oct 2003 05:09:58 -0400 From: "Timothy Bellville" To: "KR builders and pilots" Subject: Re: KR>paint Message-ID: <002b01c39557$9c4e5ae0$9f5f570c@donnas> References: <20031017134220.16208.qmail@web11006.mail.yahoo.com><3F906996.000001.02736@Computer> <1dd501c3950b$c72cd990$1202a8c0@basement> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 10 Hi Mark, I too support your conclusions on using different collars on KR's, although my own tests were less scientific. I plan on using "Nevada silver" as a base and considering a checkerboard pattern on the nose. I have fuselage mounted spring gear with no load on the wings also. As A side note, do you see any problem using feather fill over smoothprime? Tim KR2 N7038V ----- Original Message ----- From: "Mark Langford" To: "KR builders and pilots" Sent: Friday, October 17, 2003 8:07 PM Subject: Re: KR>paint > Y'all can just go ahead and call me stupid, but my airplane's gonna be red. > Again, I'll say that when the plane is sitting on gear, there are no > stresses on any composites, other than the Scotchply 3M gear legs. My wings > are covered with two layers of carbon fiber (three on the leading edge), > which you might remember, are supported by 3/8 to 1/2" of urethane foam, > which is supported by an inner layer of fiberglass. > > So let's just say my composite skin gets up to Tg, the temperature at which > the strength of the epoxy is significantly reduced. For Aeropoxy, that's > 194 degrees F for layups cured at room temperature. It's normally good for > something like 45,000 psi. I'd call "significant" something like 75%, but > lets just be conservative and say that the strength is cut in half. Now > it's down to ONLY 22,500 psi. But wait, I have a half inch layer of foam > being supporting by another layer of fiberglass that's at least 30 degrees > cooler (my inner skin). And don't forget, there is absolutely no external > influence on this surface, other than gravity pulling down on something that > weighs just about nothing. > > I actually called myself "post curing" my stub wings right after they were > constructed, by parking the plane out in the sun one hot day that summer, > shortly after construction. I taped (using clear tape) a Fluke 52 digital > recording thermometer's thermocouple to the black, unpainted surface, and > the best I can remember, the highest temperature I ever saw was 128 degrees > F. Don't forget, it's "air-cooled", just sitting there! > > Given the rule of thumb that your Tg will be raised to 50 degrees over the > post cure temp, I was probably wasting my time at that "low" temperature. > So when is it going to see 194 degrees? Never. And what effect would it > have if it DID see 194 degrees? None. And how much strength is required > of the skin, just sitting there on the tarmac? Absolutely none. And how > long does it take something as thin and massless as a .020" thick layer of > carbon fiber layup to cool off with a 30 mph breeze blowing on it during > takeoff? About 5 seconds. > > The few horror stories you hear about planes "melting" in the sun are > referring to airplanes with composite parts such as spars and stressed skins > supporting the load while parked. Neither of these apply to my plane. > > Sorry, but I have a bad habit of getting the facts, considering all aspects > of the situation, and making my own decisions. It's gonna be red, and if > y'all don't like it, you can just get over it... > > http://home.hiwaay.net/~langford/03101703m.jpg > > Mark Langford, Huntsville, AL > N56ML "at" hiwaay.net > see KR2S project at http://home.hiwaay.net/~langford > > > > _______________________________________________ > see KRnet list details at http://www.krnet.org/instructions.html ------------------------------ Date: Sat, 18 Oct 2003 08:20:19 -0500 From: "Mark Langford" To: "KR builders and pilots" Subject: Re: KR>paint Message-ID: <1e5b01c3957a$93b1fd10$1202a8c0@basement> References: <20031017134220.16208.qmail@web11006.mail.yahoo.com><3F906996.000001.02736@Computer><1dd501c3950b$c72cd990$1202a8c0@basement> <002b01c39557$9c4e5ae0$9f5f570c@donnas> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 11 Tim wrote: > I plan on using "Nevada silver" as a base and considering a checkerboard > pattern on the nose. The thing about silver is that is entirely composed of metallic aluminum chips. You might argue that it's very thin, and you'd be right, be so is aluminum foil, the stuff that people use to make ground planes out of. I was thinking about painting my plane the same color as my car, which has a little metallic in it. An electrical engineer buddy whose specialty is antennas modeled my vertical stab and antenna in some software that analyzes antenna patterns at specific frequencies. While the signal improved slightly out front (for 123 kHz), it just about got killed completely from behind, thanks to the vertical stab and rudder behind it. That's bad enough, but then it dawned on me that the other half of antenna dipole is buried INSIDE the fuselage, and beneath the aft deck, so you might as well throw that leg away entirely! That's when I went to just plain red. Based on his analysis, and the experience of others, silver paint would seriously degrade antenna performance, which is why I'm probably going with a very light gray on top instead. My thinking is that white or light gray is easy to see from above, and a dark color such as red is easy to see from below. If neither of those arguments hold water, then it's just because I like red! > As A side note, do you see any problem using feather fill over smoothprime? I don't know about Feather Fill, but I sprayed an entire layer of urethane primer over Smooth Prime on my plane. Not that it proves anything, just that I don't think there'll be a problem with what I did. Can't say about Feather Fill, since it's polyester based. Wouldn't you want to follow Smooth Prime with the primer or sealer that's recommended for your top coat? For example, DuPont's Ultimate 2K urethane primer is OK for use directly under DuPont's urethane colors, and it has a great build and is easy to sand. It's working for me. Feather Fill might be just fine, but I don't know. I guess I should let somebody that knows what they're talking about answer that one... Mark Langford, Huntsville, AL N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford ------------------------------ _______________________________________________ See KRnet list details at http://www.krnet.org/instructions.html End of KRnet Digest, Vol 192, Issue 1 *************************************