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how long to leave arch form in place???

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  • how long to leave arch form in place???

    Just laid the inner arch bricks with mortar, around a plywood frame for support. In theory, after the bricks+mortar sets for a while (how long? hours?) you should be able to remove the arch form and it shouldn't collapse, right? But I'm chicken. After a few hours of clean up, etc. things still seem a bit wobbly. I might be able to remove the form, and it all might "set" as the shape of the arch should be self supporting, right? In fact, it might be stronger in the end if things settle in-place while the mortar cures (with no form). If I leave the form in-place while the morter cures (overnight? for a few days?) does that lead to weaker joints? I did a little bit of googling and trolling of the forum archives, and was surprised that this wasn't a more obvious/common question. I guess it's just me?
    Thanks for any info & advice,

  • #2
    Once an arch is complete, the arch form can be removed immediately imo. (Actually, I waited about 30 minutes after the last brick was placed) There were two things that helped me feel confident when I dropped my form. One was having the inner arch tied in to the dome for the first couple of courses. The other was removable wedges that allowed the form to drop down for easy removal.
    Last edited by Gulf; 09-14-2015, 05:01 AM.
    Joe Watson " A year from now, you will wish that you had started today" My Build Album / My Build


    • #3
      I kept my inner arch form in until the mortar set up. I pulled the form immediately after on the flu arch, and used the same method Gulf used...wedges to drop the form down easily after last brick was set. A benefit of removing quickly was that I could clean up mortar joints.

      See my build thread here.

      See my build album here.


      • #4
        I waited overnite, took my form out today - it's still standing! Whew! I feel a little better now.
        cleaning up the inside mortar joints is what I was most concerned with, but we'll see how it goes from here.
        Thanks for the info!