web analytics
Which vermiculite (fine or coarse pellets) - Forno Bravo Forum: The Wood-Fired Oven Community

Announcement

Collapse

I'm Peter Reinhart! Ask Me Anything! Monday, February 15, 2016 7:00-8:00 pm EST

To kick off our AMA feature, we have invited author, chef and master bread maker and host of Pizza Quest, Peter Reinhart, to be our first host! Peter will be in the Forum on Monday, February 15th, from 7:00 - 8:00 pm EST. If you are unable to be online during the live session, you can post your questions in the sticky post. Peter will answer those questions during the live session on February 15th. You can view Peter's answers to your questions as well as what happened during the live session in the session thread.

Ask Me Anything New Forum Feature

You will notice a new forum at the top of the main page called, "Ask Me Anything". This forum will be used for live one hour "Ask Me Anything" (AMA) sessions hosted by people who are knowledgeable in different areas pertaining to wood fired ovens. How it works:
- Each AMA will have a "sticky" thread where the community can post questions they would like answered during the live session. This will allow everyone to participate even if you can't be online for the live session. These questions will not be answered by the host until the live AMA; if you need an answer quickly, you should post it in the appropriate Forum area for the community to respond.
- Another thread will be posted for the live AMA. Registered users who are logged in during the live session can interact with the host by asking questions and receiving responses.
- The live thread will remain in the AMA forum to view after the session.

We hope you enjoy this new feature! Please let us know if there is a topic that you'd like to have as an AMA and we'll look for a host!

Forno Bravo
See more
See less

Which vermiculite (fine or coarse pellets)

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Which vermiculite (fine or coarse pellets)

    I wish to cast an insulated base over the concrete base using vermiculite, I see there are two grades, fine and pellets, Which is the better ( I am assuming Pellets would make a much stronger aggregate)
    Also which grade would be better for the dome render (I assume fine would be easier to spread and finally what ratio, would it be the usual 5/1 mix. Thank you all

  • #2
    Re: Which vermiculite (fine or coarse pellets)

    I don't know which one is better, but I got the fine stuff, and man, its like water: I had put a couple 'drain holes' in my concrete base, so if any water got in it would drain out, and about half the vermiculite poured out of those holes before I realized what was going on! I frantically plugged up the holes, and eventually jammed window screen in to allow water to get out while keeping the vermiculite in.

    It also ends up all over the place if there is any wind.

    I wish I had used the coarse stuff ...

    Comment


    • #3
      Re: Which vermiculite (fine or coarse pellets)

      I haven't seen vermiculite packaged with the exact wording "pellets". What I bought was labeled as "course". For the hearth, I poured a 5-1, but misfigured how much it would take. Pouring on a saturday, I was about 1/2 to 3/4 " short of filling the 4" form. The nursery (where I got the "course") closed at noon for the weekend. I had to finish with expensive "fine" grade horticulture vermiculite. (The "course" is the recomended grade for insulation.) I will say though, the fine grade used in a top coat for the hearth is highly workable and yeilds a cement slick finish.
      I haven't got to the dome insulation yet but, I have seen from 8-1 to 10-1 recomended.
      joe watson

      "A year from now, you will wish that you had started today "

      My Build
      My Picasa Web Album

      Comment


      • #4
        Re: Which vermiculite (fine or coarse pellets)

        Originally posted by sonomacast View Post
        I wish to cast an insulated base over the concrete base using vermiculite, I see there are two grades, fine and pellets, Which is the better ( I am assuming Pellets would make a much stronger aggregate)
        Also which grade would be better for the dome render (I assume fine would be easier to spread and finally what ratio, would it be the usual 5/1 mix. Thank you all
        I find that the finer grade is more workable in that it is less crumbly and you can therefore use less cement. However it also needs more water which has to be removed later and more water means more time for removal. For the mix over the dome I think 5:1 is way too rich. Remember that even a 10:1 mix uses the same mass of cement as vermiculite and increasing density, although increasing strength, decreases insulation value, so the less cement used the better. I discovered that a 50/50 mix of perlite and vermiculite makes an excellent mix with a lean cement addition. i.e. 5:5:1:3 vermiculite,perlite,portland cement, water. However the source of the materials available will differ depending where they come from so do your own tests.
        Good luck, hope this helps.
        Kindled with zeal and fired with passion.

        Comment


        • #5
          Re: Which vermiculite (fine or coarse pellets)

          Originally posted by Mingy View Post
          I don't know which one is better, but I got the fine stuff, and man, its like water: I had put a couple 'drain holes' in my concrete base, so if any water got in it would drain out, and about half the vermiculite poured out of those holes before I realized what was going on! I frantically plugged up the holes, and eventually jammed window screen in to allow water to get out while keeping the vermiculite in.

          It also ends up all over the place if there is any wind.

          I wish I had used the coarse stuff ...
          If using drain holes, which is a really good idea, glue some fibreglass insect screen over the holes from the inside. Sorry, I suppose this advice is a bit late now.
          Kindled with zeal and fired with passion.

          Comment


          • #6
            Re: Which vermiculite (fine or coarse pellets)

            Thanks all

            Comment

            Working...
            X