The wings of the Skybolt have laminated curved structures called wigtip bows. These bows are roughly one-half circle with a 21" radius on the outer surface. They are constructed by laminating six pieces of spruce, 1/8" thick by 3/4" wide to make a bow that is 3/4" x 3/4". I constructed my jig by screwing 2"x2"x4"L blocks to the surface of the table, around the outer circumference of the radius that I drew on the table. I decided to make my bow circles about 3/4 circles, so I could cut pieces off the end and use actual sections of the finished piece to test for failure. I took a damp cloth and wiped both sides of the capstrip to dampen the wood, as this glue needs moisture to activate it. I put a bead of glue on the surface of one side (not both sides like epoxy) of the strip and used a 1" brush to spread it evenly across the 3/4" surface. I then placed these pieces in the jig. Using quick-clamps, I clamped the bundle of capstrip to the jig. I then used 2" springclamps to clamp the bundle together between each jig block/quick-clamp. This effectively administered clamping force around the entire surface of the radiused bundle of capstrip. I allowed each assembly to cure for 24hrs before removing from jig. The gluethat seeps out expands to a foam-like consistancy along the top edge of the bundle. This is where glue seeps out during the claimping process. This glue is not "easily removed" as the manufacurer says. After trying a very sharp gasket scraper, I found the best way to remove the excess was by using a wire wheel in a power drill, being careful not to errode the wood with the wire wheel. I then cut off lengths of the bow at both ends. I loaded one piece into a vice with the jaw vice bordering the mid-point of the lamination along the horizontal edge, and hit it with a hammer to the point of breaking the laminated pieces apart. I took the piece of the other end and put it into a vice and used a screwdriver to pry the pieces apart. In both instances, on every bow, I had failure of the wood and not the glue. Subsequent scraping of the wood in the broken joints showed the glue to have penetrated the wood significantly. While constructing, I also produced a small section of this type of assembly, but did not clamp it together tightly. I merely weighted it down, such as can be done with epoxy. Testing of this piece showed clear failure of the glue and not the wood. It appears to me that thorough clamping of the assembly is important to the integrity of the glued joint. Although this glue will expand to fill gaps, the expanded foam does not appear to have the same strength as that which is not expanded. My conclusion: I am happy with the results and my testing gives me confidence in the final assembly. However, due to the inability to fill gaps in a manner which will still maintain strength, I would not recomment this glue be used in any application that does not allow sufficient clamping pressure along the entire area of the surfaces to be joined. It will not fill gaps like T-88 will. But, it does not appear to suffer from issues of glue-starved joints like T-88 does. As always, these opinions are mine, and they're free, so thake them for what they are worth.
Scott __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
