Quote:
Originally Posted by rabbit
As an addendum on the great Flange Controversy, it occurs to me that when the halves of Humpty were laid up, that flange was basically there to get em to "pop". All molds have draft or taper in the direction of eventual removal of the part (if they don't the part is very effectively trapped and the mold has to be destroyed to get it out). I have seen shallow draft molds from which parts jumped up or popped on their own and I have seen some that took a lot of compressed air and prying to lift. Can't pry without something to pry against so I'm guessing that the flange is primarily a place to put a wedge or crow and also some reinforcement to maintain the shape of the part at what becomes the centerline when mated with other half. More of a fabrication necessity than a contributor to final strength of the centerline joint.
jack
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While I am not disagreeing with you on ease of extraction from the mold, Trilliums don't have a flange just a thickened band where the two halves meet. They also are notorious for belly band leak issues. Last
Fall I got a chance to examine a new
Scamp. I took particular note of how much better the belly band was constructed. The flange becomes the first line of defense against
leaks with sealing the seam second. On Trilliums all you really have is the seam seal. Not as good in my opinion. Second , take a piece of sheet metal. Very easy to roll up. Now, bend one end 90* and try and roll it. Whether intentional or not, the flange has to add strength. Finally, good point on the taper of the mold. While obvious, it never occurred to me the limitations the mold puts on the appearance of the body. The shape of the
Burro, in particular the
lights, could not be easily done with a horizontal belly band. You couldn't get out it of the mold. Raz