Date: Wed, 12 Jun 2002 21:02:05 -0400 From: "Marc J. Zeitlin" Subject: COZY: Not an Oaf's Story, but pretty close Zeitlin's Top Ten Methods of Determining You Have a Fuel Leak in Your COZY MKIV Fuel Tank: 10) You're not sure you had enough flox on the top of the bulkheads when you installed the strake top. 9) When you originally did your tank pressurization test, there was a very slow bleed-down of pressure. 8) When you got a refrigeration guy to fill the tank with freon and then use a sniffer to look for leak points, you couldn't find any, either in the layups or in the tubing. But the bleed-down still occurs. 7) When you put 2.5 gallons of 100LL in each tank to flush the fuel system, everything seems fine, but when you park the plane nose down, you hear a slight "blup, blup, blup" on 3 second intervals coming from somewhere near the front corner of the left tank. 6) When you frantically search all over the damn place for fuel leaking out, you don't see any, but the "blup, blup, blup" sound continues for about 5 minutes. 5) When you extend the nose gear again, and level the aircraft, the "blup, blup, blup" sound goes away. 4) When you lower the nose again to park the plane for the evening on Sunday, you hear the "blup, blup, blup" for another minute or two, and then it stops. 3) When you go out on Tuesday morning to put the upper cowling over the engine because it might rain, you sniff a bit of 100LL smell, coming from other than the vent holes. 2) When you open up the canopy, you get a good whiff of 100LL. And last, but not least, the number one method for determining you have a fuel leak: 1) When you look inside the canopy, you see 100LL fuel very slowly dripping it's way down from the forward area of R33, along the bottom strake surface, into the newly painted map compartment (did you know that 100LL will dissolve "Fleckstone" paint as well as the "wingwalk" paint that ACS sells?) and thence down the fuselage side into the small area under the stick/aileron trim cable, out the drain hole drilled two days before, along the bottom fuselage to the nose, and down onto the driveway. The planned solution: Remove the inner surface of R33 along with the foam, as well as 1" of the inner surface of the top and bottom strake skins close to R33. I should then be able to find the leak, patch it, and replace the removed foam and skin. After some local sanding and repainting, it should be good as new. Maybe one or two weekends down the drain, but that's the nice thing about composites - anything is fixable. I'll also need to polish the blue streak off of the white paint on the fuselage bottom - the fleckstone in blue runs nicely :-). -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://users.rcn.com/marc.zeitlin/ From ???@??? Thu Jun 13 23:37:17 2002 Return-Path: Received: from mx03.mrf.mail.rcn.net ([207.172.4.52] [207.172.4.52]) by mta03.mrf.mail.rcn.net with ESMTP id <20020614032751.KYPH23623.mta03.mrf.mail.rcn.net@mx03.mrf.mail.rcn.net>; Thu, 13 Jun 2002 23:27:51 -0400 Received: from alum.mit.edu ([18.7.21.81]) by mx03.mrf.mail.rcn.net with esmtp (Exim 3.35 #5) id 17Ihkd-0005NH-00 for marc.zeitlin@rcn.com; Thu, 13 Jun 2002 23:27:51 -0400 Received: from twc2.betaweb.com (ns.betaweb.com [216.231.140.250]) by alum.mit.edu (8.9.2/8.9.3) with ESMTP id XAA16245; Thu, 13 Jun 2002 23:27:50 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.9.3/8.9.3) id EAA01769 for cozy_builders-list; Fri, 14 Jun 2002 04:27:57 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@canard.com using -f Received: from m12.boston.juno.com (m12.boston.juno.com [64.136.24.75]) by twc2.betaweb.com (8.9.3/8.9.3) with ESMTP id EAA01763 for ; Fri, 14 Jun 2002 04:25:10 -0400 From: alwick@juno.com Received: from cookie.juno.com by cookie.juno.com for <"L941HVjjYzDhN3itp//mkC85Nw/DLUE+XORo1ui3z2RG2bKx3qO0Jw=="> Received: (from alwick@juno.com) by m12.boston.juno.com (jqueuemail) id G48Y9685; Thu, 13 Jun 2002 23:21:04 EDT To: cozy_builders@canard.com Date: Thu, 13 Jun 2002 13:22:19 -0700 Subject: Re: COZY: Not an Oaf's Story, but pretty close Message-ID: <20020613.201925.-247187.1.alwick@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Juno-Line-Breaks: 4,7-12,14-16,18-20 Sender: owner-cozy_builders@canard.com Precedence: bulk Reply-To: alwick@juno.com I took small drill bit, added duct tape to it to control how deep it penetrates. Then I drilled holes in skin at leak locations. Even though tanks had been empty for a week, fuel dripped out. I then used a syringe to inject epoxy into hole. I had to enlarge syringe exit hole to get epoxy to flow. this worked well. I found my leaks followed the score lines that we do to foam when building strake lids. Makes sense. If I were to ever make strakes again, I would fill the score lines with micro before glassing. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 140+ hours on engine/airframe Prop construction, Auto conversion, and Glass cockpit details: http://members.aol.com/alwick/ On Wed, 12 Jun 2002 21:02:05 -0400 "Marc J. Zeitlin" writes: > Zeitlin's Top Ten Methods of Determining You Have a Fuel Leak in Your > COZY > MKIV Fuel Tank: ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! 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