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Post mortem on foam ramp failure
Posted by:
Michael Danek
(---.adr02.mskg.mi.frontiernet.net)
Date: February 22, 2015 05:48PM
I did the post mortem on the ramp failure mentioned in my earlier post about trying to get a filled epoxy to toughen up the foam ramp "shell" of wrap epoxy I now use. There was a void, but not where the thumb would touch the rod, but at the bottom of the ramp. Also, it appears that this foam ramp was slightly oversize and I didn't get the gap between the ramp and the blank fully filled with epoxy (rod bond). The failure occurred right at the front of the ramp, where it is the most fragile. I think the combination of the two defects was enough to result in not a denting or crushing failure, but a structural failure. Everywhere on the ramp the ramp feels like a rock. It appears that there is no way a normal load, or even the edge of a rod holder, would dent or cave in the shell. But the stress on this heavy action rod, with the defects mentioned, was enough to crack the shell right where the front edge of the foam ramp met the solid epoxy filet between the ramp and the blank. Because it is at the bottom, it would have been a compression failure.
My conclusion is that this failure may not have happened if I had done a proper job of epoxying the ramp, void or no void. The un-epoxied volume under the forward edge of the ramp possibly had more to do with the failure than the foam void. By the way, this was not a Riley Rods foam ramp as I thought, it was a blonde foam reel seat shim. If you want pics, let me know and I'll process them for the photo section. Sorry, only registered users may post in this forum.
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