Re: [bolger] Re: pouring foam, bottle pressure
In a message dated 6/13/02 10:26:36 AM Central Daylight Time,
lincolnr@...writes:
by foam during the pour, but rather that they might contract in cold weather,
breaking the bond (if any) with the foam. This seems a pretty far-fetched
concern when looked at in the light of day.
Ciao for Niao,
Bill in MN
[Non-text portions of this message have been removed]
lincolnr@...writes:
> No need to pressurize the bottles.On reflection, I agree. My concern was not that the bottles would be crushed
by foam during the pour, but rather that they might contract in cold weather,
breaking the bond (if any) with the foam. This seems a pretty far-fetched
concern when looked at in the light of day.
Ciao for Niao,
Bill in MN
[Non-text portions of this message have been removed]
No need to pressurize the bottles. If there is so much pressure that
the bottles are crushed, you probably have enough foam to fill the
space. If not, the fluffier foam and crushed bottles should fill the
same space and weigh the same as the denser foam and pressurised
bottles. THe point is to keep the foam from being so confined it gets
to high pressure. If there's enough pressure to crush the bottles
significantly, there may be enough pressure to stress or bulge your
boat's structure. I read an essay where a guy was using poured foam as
a structural core for his full sized glider's ailerons. He capped them
over too soon and the foam kept expanding, causing a bunch of
non-aerodynamic lumps. This sounds like the foam I know from my own
experiences. One way to keep the pressure down would be to do multiple
small pours. It sets up in minutes, tho maybe, per the glider guy's
experience, there is a slight increase later.
the bottles are crushed, you probably have enough foam to fill the
space. If not, the fluffier foam and crushed bottles should fill the
same space and weigh the same as the denser foam and pressurised
bottles. THe point is to keep the foam from being so confined it gets
to high pressure. If there's enough pressure to crush the bottles
significantly, there may be enough pressure to stress or bulge your
boat's structure. I read an essay where a guy was using poured foam as
a structural core for his full sized glider's ailerons. He capped them
over too soon and the foam kept expanding, causing a bunch of
non-aerodynamic lumps. This sounds like the foam I know from my own
experiences. One way to keep the pressure down would be to do multiple
small pours. It sets up in minutes, tho maybe, per the glider guy's
experience, there is a slight increase later.