Forno Bravo Forum: The Wood-Fired Oven Community

Forno Bravo Forum: The Wood-Fired Oven Community (http://www.fornobravo.com/forum/)
-   Getting Started (http://www.fornobravo.com/forum/f6/)
-   -   Pool Crete vs. Mixing Vermiculite (http://www.fornobravo.com/forum/f6/pool-crete-vs-mixing-vermiculite-10593.html)

rcolombo 01-25-2010 09:47 AM

Pool Crete vs. Mixing Vermiculite
 
Can i use pre-mixed bags of pool crete in stead of mixing my own vermiculite and portland cement?

Fairview WFO 01-25-2010 05:53 PM

Re: Pool Crete vs. Mixing Vermiculite
 
If pool crete is just perlite and Portland cement then yes, otherwise no. You want just perlite or vermiculite and portland without any other aggregates for maximum R value. If you have a large percentage of sand or other filler it will transfer the heat to fast. There are several threads here where people even want to limit the amount of Portand cement used to boost R value. I would stick with the recipe in the manual. It not hard to mix because the stuff is so light. If you have a mixer its a breeze, if you have to mix in a tub its still not that bad when compared to mixing concrete.

david s 01-26-2010 12:16 AM

Re: Pool Crete vs. Mixing Vermiculite
 
Too much mixing in a mixer tends to break down the volume (particularly perlite) The grains seem to abrade away. The trick is not to overdo the mixing.

GianniFocaccia 01-27-2010 10:49 AM

Re: Pool Crete vs. Mixing Vermiculite
 
1 Attachment(s)
The value of mixing your own vermiculite and portland cement is that you control the proportions and resulting R value. After reading through the many threads here regarding vermiculite-to-cement ratios, (from 5:1 through 11:1) I decided on an 8:1 ratio for a little bit higher insulation value and because the sides of my insulating layer would not be exposed. The 8:1 mix was easily mixed in a wheel barrow (gently!) like folding egg whites into waffle batter only on a larger scale. I placed 2" of Insboard 19 on top of 3 1'2" of vermicrete and the resulting compressive strength of the install turned out solid as ever.

stonejohn 01-27-2010 05:08 PM

Re: Pool Crete vs. Mixing Vermiculite
 
Hi Guys, just jumping in with a question, Is perlite and vermiculite the same? I thought they were different. I thought perlite was like whitish pelllets and vermiculite was the stuff in pool bases. If they are different is one better then the other?
thanks
J

Tscarborough 01-27-2010 05:55 PM

Re: Pool Crete vs. Mixing Vermiculite
 
They are the same mineral, processed differently.

dmun 01-27-2010 08:44 PM

Re: Pool Crete vs. Mixing Vermiculite
 
Vermiculite is a rock:
http://www.thedailygreen.com/cm/thed...iculite-md.jpg
Perlite is a rock:
http://www.venturesunlimited.ca/images/perlite.jpg
They both have the unusual property of popping like popcorn when heated.

They both work fine for oven insulation. Perlite has the advantage of never occurring near deposits of asbestos, although all vermiculite now sold in the US is "certified asbestos free"

david s 01-28-2010 03:36 AM

Re: Pool Crete vs. Mixing Vermiculite
 
The perlite we get here tends to abrade with mixing more than vermiculite. It is a slightly better insualtor, ie it is slightly less dense,but the difference is marginal. I prefer to use vermiculite because it contains less dust than perlite, which I find irritating to inhale.

Neil2 01-30-2010 01:28 PM

Re: Pool Crete vs. Mixing Vermiculite
 
"The trick is not to overdo the mixing."

I agree with David. Mix it gently by hand (shovel and wheelbarrow). Avoid using a mixer.

Neil2 01-30-2010 01:30 PM

Re: Pool Crete vs. Mixing Vermiculite
 
"Is perlite and vermiculite the same? "

Both will do the job equally well. Go for whichever is cheapest. (Try to get the coarse perlite if going with perlite)


All times are GMT -7. The time now is 01:16 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC