Re the foam:
I am puzzled, how can John Crockett's green foam be specified at 1.5
pounds per cubic foot, if his scrap green piece 4 x 6 x 9 inches
weighing 125 grams would, as a cubic foot, actually equal around 2.2
pounds? (if I did my maths right :-)
John's green foam piece was approx. the same weight-for-size as my
grey piece.
The original Crown SASS foam weighs the same as my grey piece.
Rob Danielson was using 1.5 to 1.7 pounds per cubic foot density foam.
I guess it is hard to accurately weigh a small piece of foam, so
maybe some variations have occurred because of that.
But if the weights of the smaller pieces was accurate, then this
suggests John Hartog's link to the Grainger charcoal foam of 2 pounds
per cubic foot would be the closest match to the original Crown SASS
foam.
Vicki Powys
Australia
John Crockett wrote:
> BTW, my green foam, at 1.5 lbs per cubic foot density, is similar
> to the foam linked to on the diyboundarymic blog. So maybe it is
> the "right" stuff. Just not identical to what Crown is using, which
> may be proprietary.
> On 12/07/2012, at 2:08 AM, John Crockett wrote:
>
>
>> Hi Vicki,
>>
>> The foam I am able to find locally is green (whatever that means!).
>> It is called high-density foam (they also sell "regular" density,
>> which is white), and although the clerks in the store had no idea
>> about open or closed cell, it is absorbent like a sponge, so I
>> guess it is open-cell. It isn't nearly as dense as I expected, less
>> so, I think, than the foam mattress pad I mentioned. It is quite
>> squishy. The 4" x 6" x 9" scrap I bought weighs 125 grams.
>>
>> Could I possibly have the right thing? I can return it if I bought
>> the wrong material, but how can I tell? Does anyone know?
>>
>> Many thanks,
>>
>> John Crockett
>> Westminster, Vermont
>>
>
On 15/07/2012, at 6:05 AM, hartogj wrote:
> The price $45.12 suggests the charcoal firm.
>
> I notice the charcoal firm at foamforyou.com is density is 1.5-1.7
> lbs./cu.ft. The grainger.com charcoal sheet that I previously
> linked to is 3 lbs./cu.ft. Grainger also lists 2 lbs./cu.ft
> charcoal sheets, and 1.45 lbs./cu.ft balls and cubes.
>
> John Hartog
> rockscallop.org
>
> --- In Peter Shute <>
> wrote:
>>
>> It works ok as http://www.foamforyou.com/charcoal_foam.htm#
>> Charcoal (I removed one space, hopefully the list doesn't put it
>> right back again).
>>
>> There are two densities of charcoal foam, and that both are listed
>> as suitable for noise treatment and packaging. Which one?
>>
>> Can anyone see anything on the specs page that distinguishes these
>> from the other foams, apart from colour? They aren't the densest.
>> Maybe low resilience?
>>
>> Peter Shute
>>
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