In re: density calculation
At 7.481 gal/cu ft your conversion is correct, although, out of ignorance I
can't comment on the plastic wood comparison. One of my reference texts
shows white fir at 28.1 lb/cu ft, white pine at 34 lb/cu ft, and several
others (hardwoods, not conifers) at higher density. Spruce is not listed
but you are probably correct (and if not it's close enough).
Best regards,
Rob Housman
A070
-----Original Message-----
On Behalf Of R.H.Mole@open.ac.uk
Sent: Friday, January 05, 2001 1:27 PM
Subject: RE: SuperFil vs. Expancell...
Would someone verify my calculations that Superfill is like plastic wood, in
the sense that it weighs about 28 lbs/ft3, the same as Spruce?
Its advertised as 3.68 lbs/US gallon. So if my density conversion is
correct, then anyone putting 1/8'th of an inch above the spar is adding the
equivalent of a 1/8'th inch wooden spar cap - as far as weight is concerned
- without any structural benefit whatsoever. Another cut on this is to say
that it weighs about 0.8 lbs/yd sq when 1mm thick.
Richard Mole
> -----Original Message-----
> From: Shaun Simpkins [SMTP:shauns@hevanet.com]
> Sent: Friday, January 05, 2001 3:13 PM
> To: Jonathan Moyle; Europa club
> Subject: Re: SuperFil vs. Expancell...
>
> Now that several opinions are in, perhaps I can summarize what's been said
> since I started the thread.
>
> 1. Superfil has better consistency than Expancel + Epoxy, but this is user
> dependent.
> 2. Superfil mix ratio can't be changed.
> 3. Superfil must be applied and cured at fairly high temps (77F)
> 4. Superfil sands easily, but not necessarily any easier than Expancel
> 5. Superfil is harder and therefore more resistant to denting than
> Expancel,
> but is somewhat
> rougher and may not offer as smooth a fill
> 6. Superfil is lighter than Expancel+Epoxy
> 7. Superfil may save some time
> 8. Superfil is not good for thick buildups beyond 1/8"
>
> So from this, there isn't a clear win for either option. The issue of
> lightness and durability seems
> most germaine, so let me follow these opinions.
>
> 1. Just how much filler are we talking about on a typical XS? 1 Gallon?
> 2. How much lighter is Superfil than Expancel+Epoxy? Poly-Fiber quotes
> Superfil at 3.7lbs/gal.
> 3. How much lighter in total? A few ounces? Several pounds?
> 4. Expancel is heat-expanded gas-filled plastic spheres. We get the
> expanded stuff. Does Expancel
> suffer further expansion under post cure/use? Does Superfil?
>
> Thanks -
> Shaun Simpkins
> A207
>
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