From: AlWick@aol.com Date: Wed, 13 Aug 1997 15:03:24 -0400 (EDT) Subject: COZY: Main spar construction As you all know, the instructions are very well done. If there are critical dimensions, Nat has done well to flag those. One of the few components that is not flagged is the main spar. Now that I have closed up my strakes, I finally realize how important the spar dimensions are in the construction process. Just wanted to warn those who have not yet made the main spar. The only side of the spar that does not have significant dimensions is the front face. The top and bottom faces end up being flush to the strake top. If you build the spar too thick, or the wrong slope, you will not end up flush to the strakes. Even though the spar is hell for stout, if you sanded the top to make it flush with the strake, you may be compromising the structure. Mine came out ok, but I am concerned that others may have problems. FWIW -al From: "McElhoe, Bruce" Subject: Re: COZY: Centre Spar Lamination Date: Fri, 10 Oct 97 17:11:00 HST Ian-- It appears someone has already suggested injecting epoxy in the void. No sanding required. You don't need a bond, you're just trying to fill the void so the foam supports the layup and the glass won't deform easily. Drill a small hole and an air vent. Use a large syringe, squirt in enough pure to fill it up. Finding a big syringe is best. Try to figure how to do it without the needle. It may help to heat the epoxy so it flows better. It will be as good as anybody's. Good luck. ---------- From: owner-cozy_builders To: Cozy Builders Subject: Re: COZY: Centre Spar Lamination Date: Friday, October 10, 1997 9:48PM There was a typo in the previous post. The air "run" is about .25" wide and goes lengthwise along the side of the center spar close to the top corner (where the glass was wrapped around the corner). It covers almost the entire length of the pilot side before the bend to the straight centre section. There appears to be some other air pockets near the center of the side panels (looks like a clamp or weight was there as they are perfect circles). If I inject epoxy how do I sand first? -- Ian D.S. Douglas #0069 Date: Fri, 10 Oct 1997 20:37:40 -0400 From: Ian Douglas Organization: WTC Subject: COZY: Centre Spar Lamination Hi again, I was looking over the centre spar (in the daylight) and have noticed that there a re long runs of air near the corners running length wise. Is there a way to repair this or do I have to grind/sand the fiberglass off and re-apply? -- Ian D.S. Douglas #69 Date: Fri, 10 Oct 1997 21:48:06 -0400 From: Ian Douglas Organization: WTC Subject: Re: COZY: Centre Spar Lamination There was a typo in the previous post. The air "run" is about .25" wide and goes lengthwise along the side of the center spar close to the top corner (where the glass was wrapped around the corner). It covers almost the entire length of the pilot side before the bend to the straight centre section. There appears to be some other air pockets near the center of the side panels (looks like a clamp or weight was there as they are perfect circles). If I inject epoxy how do I sand first? -- Ian D.S. Douglas #0069 Date: Fri, 10 Oct 1997 22:32:42 -0700 (PDT) From: "Mr. Radon" Subject: Re: COZY: Centre Spar Lamination Join the club. I did my spar shear web layup last weekend. My first BIG goof. Wanted to ball the whole thing up and heave it into the trash. A few days of rain and a call to Nat cooled me down. Nat said to fill the voids with epoxy, sand the bump flush. The fiber glass to Urethane bond isn't so great anyhow, so the bubles aren't a big concern, the levelness is. I've layed off to catch up with work and figure out how flush it will need to be. I don't want to cut into the layers and weaken the shear web. I am doing research into the wing to Spar joint, I know that you need a flat spar, no bumps or joggles. Since I have a slightly uneven spar cap recess (due to air voids) this will translate into an uneven cap at the surface unless I fill it, which you don't want to do. Hence an uneven surface. I guess I could level the LWA's out with a little extra flox. Anyhow, to sum-up Nat said it was okay. I tryed like the dickens to get that layup perfect, ughhhh!!!!! To thoughs of us who have joined the Wing to Spar, what am I looking at?, is .063" - .0125" a whole lot to worry about??? ROY - Cozy going at the same pace the 747 & 737 lines........ > Hi again, > > I was looking over the centre spar (in the daylight) and have noticed > that there a re long runs of air near the corners running length wise. > Is there a way to repair this or do I have to grind/sand the fiberglass > off and re-apply? I think if you do this your going to destroy the part with a big "D". From: "norm & monda" Subject: Re: COZY: Centre Spar Lamination Date: Sat, 11 Oct 1997 09:02:37 -0400 get a eaa tech counsler to look at it. this sort of thing its dangerous to speculate about over the web not being able to see it personally. ---------- > From: Ian Douglas > To: Cozy MK IV Builders > Subject: COZY: Centre Spar Lamination > Date: Friday, October 10, 1997 8:37 PM > > Hi again, > > I was looking over the centre spar (in the daylight) and have noticed > that there a re long runs of air near the corners running length wise. > Is there a way to repair this or do I have to grind/sand the fiberglass > off and re-apply? > -- > Ian D.S. Douglas > #69 Date: Thu, 16 Oct 1997 11:02:40 -0400 From: Ian Douglas Organization: WTC Subject: Re: COZY: Centre Spar Lamination Hi All, As was suggested I sent Nat an e-mail about the delamination of the centre spar. His replay follows: > Dear Ian, > Checked the locations you call out, and the repair recommendations still > apply, namely, inject epoxy in the voids. If the entire surface is flat > after filling the voids, fine, you are done. If there are bumps higher that > 1/16" after filling voids with epoxy, then sand the entire surface flat, > and cover with one layer BID, extending at least 1/2" past any areas where > you sanded through one or more layers of glass. > Wicks is presently out of RAE epoxy, but making arrangements to obtain it > from a new source (per Jerome Hediger, Manager). In the meantime, if you > need epoxy, PTM&W Aeropoxy is an acceptable epoxy, and can be used > alternately with RAE. Regards, Nat It would appear that the message from Roy Radon "Mr. Radon" was correct about the flat requirement. -- Ian D.S. Douglas TEL (613) 599-5046 Director of Technology CEL (613) 724-6382 Workplace Technologies Corporation FAX (613) 764-3280 135 Michael Cowpland Drive INET douglas@ibm.net Kanata, Ont. Canada K2M-2E9 From: cdenk@ix.netcom.com Date: Thu, 16 Oct 1997 17:27:15 -0500 (CDT) Subject: Re: COZY: Centre Spar Lamination Douglas writes The repair procedure calls for replacing all damaged (by sanding) plys with like material and orientation, AND then 1 ply BID. I wonder if something didn't get lost in the translation. Carl Denk: "cdenk@ix.netcom.com" Date: Fri, 17 Oct 1997 21:06:46 -0400 From: Ian Douglas Organization: WTC Subject: Re: COZY: Centre Spar Lamination Carl, It would appear that somewhere along the line a miscommunication occured. The piece that I have is currently flat (no 1/16" bump) with a white area (suggesting a delamination). The message I sent should have said IF I end up with more than a 1/16" bump (AFTER injecting the epoxy - for what ever unknown phenominum) THEN I would have to do the sanding and repairs to the glass. BUT, IF after I inject the epoxy the white area disappears AND there is NO bump THEN I am finished, according to Nat. Since Nigel Field lives quite close to me, I may ask him to come take a look (once I have the garage cleaned up). -- Ian D.S. Douglas MK 0069