---------------------------------------------------------- RV9-List Digest Archive --- Total Messages Posted Fri 06/04/04: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:06 AM - First major mistake of my project on HS spar countersinking. Need opinions on fix! (Bob Smith) 2. 08:14 AM - Re: First major mistake of my project on HS spar countersinking. Ne... (Neilekins@aol.com) 3. 06:43 PM - Re: First major mistake of my project on HS spar countersinking. Need opinions on fix! (John Oliveira) ________________________________ Message 1 _____________________________________ Time: 08:06:53 AM PST US From: "Bob Smith" Subject: RV9-List: First major mistake of my project on HS spar countersinking. Need opinions on fix! --> RV9-List message posted by: "Bob Smith" Hi, folks! I've appreciated all the help people have given on this list, and now I've got my first major screw-up to deal with. I'm a new RV-9 builder working on my horizontal stabilizer, and made a mistake countersinking the spars - I went too deep. I did not read section 5 of the manual carefully enough and tried to countersink enough to get the dimpled skin material to lie flush on the spar. Bad idea! Now many of the holes are slightly enlarged. I did not discover this until I was ready to rivet on the back spar, which appears to have been done slightly deeper than the front spar, though both are too deep. I talked to factory support via e-mail about this and their suggestion was to use a 0.032 backing strip that I use to sandwich the spar from behind. This would mean drilling out all the rivets I've put in the front spar and putting strips in between the rib bays, and also the back spar. While I don't really want to start over, I'm only about 40 hours into a 1500 hour project, so that is an option I could tolerate. Do you guys/gals think the backing strips would work OK? I'm concerned that in drilling out all the rivets that are already in the spar that I risk messing up the holes even more, and having to drill them out and use larger rivets, and need a larger dimple set, etc, and basically end up with a cobbled-together mess. Anyway, any opinions appreciated! Bob Smith ________________________________ Message 2 _____________________________________ Time: 08:14:03 AM PST US From: Neilekins@aol.com Subject: Re: RV9-List: First major mistake of my project on HS spar countersinking. Ne... --> RV9-List message posted by: Neilekins@aol.com I would get a new spar. Its your butt up there. It cant cost that much....Neil ________________________________ Message 3 _____________________________________ Time: 06:43:56 PM PST US From: "John Oliveira" Subject: Re: RV9-List: First major mistake of my project on HS spar countersinking. Need opinions on fix! --> RV9-List message posted by: "John Oliveira" that is a common problem. Follow the factory advice. I had some holes that were also to large and just used a backing plate as they suggest. No harm done. Plenty strong enough. Chalk it up to experience. John Oliveira RV9a - N909RV Reserved Working on fuselage ----- Original Message ----- From: "Bob Smith" Subject: RV9-List: First major mistake of my project on HS spar countersinking. Need opinions on fix! > --> RV9-List message posted by: "Bob Smith" > > Hi, folks! I've appreciated all the help people have given on this > list, and now I've got my first major screw-up to deal with. I'm a new > RV-9 builder working on my horizontal stabilizer, and made a mistake > countersinking the spars - I went too deep. I did not read section 5 of > the manual carefully enough and tried to countersink enough to get the > dimpled skin material to lie flush on the spar. Bad idea! Now many of > the holes are slightly enlarged. I did not discover this until I was > ready to rivet on the back spar, which appears to have been done > slightly deeper than the front spar, though both are too deep. > > I talked to factory support via e-mail about this and their suggestion > was to use a 0.032 backing strip that I use to sandwich the spar from > behind. This would mean drilling out all the rivets I've put in the > front spar and putting strips in between the rib bays, and also the back > spar. > > While I don't really want to start over, I'm only about 40 hours into a > 1500 hour project, so that is an option I could tolerate. Do you > guys/gals think the backing strips would work OK? I'm concerned that in > drilling out all the rivets that are already in the spar that I risk > messing up the holes even more, and having to drill them out and use > larger rivets, and need a larger dimple set, etc, and basically end up > with a cobbled-together mess. > > Anyway, any opinions appreciated! > > > Bob Smith > >