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Jim Hicks
Registered: May 2007
Location: Maryland
Posts: 135
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Sat April 18, 2009 12:16pm
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8# foam with 8x expansion. I've poured the foam directly into the mounted reel seats a few times with no problems but decided to test how much leeway there was in measuring before I got a blowout. Above is two examples of blowouts from the test batches. A test pour showed that 1 dram of foam remained in the cup after pouring. The volume of the "reel seats" ar 8 drams. Mixing up 2 drams would have 1 dram in the seat and expanding to 8 drams. Top row is a careful measure with the base EVA tenon friction fitted to the seat. The top tenon is simply a 1/4# slice off of the bottom tenen and it's slid into the seat after the pour. I was able to get up to a 4x pour without incident but the second and third rows show some test blowouts. Row two is mixing 4 drams, 1 dram remains in the cup and the other 3 would expand to 3 times the volumn of the seat unless the EVA plug could stop the expansion. The foam expands from the bottom so the pressure is much higher there than at the top. The unsealed bottom tenon allowed the foam to squeeze through. In the third row I mixed 5 drams, 1 remains in the cup and 4 go in the seat for 4 times the seats volume. I had the bottom tenon sealed with 5 min epoxy and although two of these tests worked well the third test blew out the top tenon.
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Jim Hicks
Registered: May 2007
Location: Maryland
Posts: 135
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Sun April 19, 2009 12:05am
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To get the volume of the space inside the seat you calculate for the blank and subtract that from the calculation for the seat. All measurments should be in the same unit, inches or milimeters etc. Cubic volume is equal to radius (half the diameter) times radius times pi (3.14) times length. In the above samples the section to be filled in was 3 1/8" in length; the "blank" would be .25" radius times .25" radius times pi (3.14) times lenght 3.125" = 0.614 cubic inches; the "seat" would be .5" radius times .5" radius times pi (3.14) times length 3.125" = 2.454 cubic inches. 2.454 cubic inches minus 0.614 cubic inches = 1.84 cubic inches of volume to be filled. My measuring cup doesn't have cubic inches so I converted to drams (1 cubic inch = 4.43 drams) which results in 8.15 drams.
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