Replies

1. 
   MikeHennessy | Nov 27, 2007 04:30am | #1

   I'm not sure what you are asking. Do you want to edge join your boards to make a 22" wide mantle, or glue two 3/4" boards together to make a board 1-1/2" thick?

   Mike Hennessy
   Pittsburgh, PA

1. 
   user-90774 | Nov 27, 2007 04:33am | #2

   Sorry...1  1/2 inch thick

2. 
   oldusty | Nov 27, 2007 08:05am | #3

       dd ,

               Just spread plenty of glue and clamp the pee wadden out of it create a clamp monster .

            Imo I would trim the boards to final size after glue up to allow for some movement during clamp up .

                regards           dusty

3. 
   BobSmalser | Nov 27, 2007 08:28am | #4

   1) Set the stock next to the fireplace until it arrives at 6% MC or less.

   2) Laminate the boards so the grain of each board moves together seasonally instead of against each other. In other words, don't "flip the cups", but lam the boards so all the growth rings are parallel to each other.

4. 
   cowtown | Nov 27, 2007 12:16pm | #5

   Golly, deputy dawg, my puppies eat biscuits too, but that don't make em experts in their applications.

   Just a tad ruff, (no pun intended), but with a 22" wide mantle, you are significantly impeding the heat rise off of the fireplace.

   Who cares? well most fireplace insert mfgrs do, cause they publish nomographs which outline the max projection at specific heights above their fireboxes.

   Why are they so specific,

   Well, to my simplistic undertstanding, not as a fire/forensic specialist, but rather a fella who has been on the other side of the equation, the problem is not the actual risk of flame spread, but rather the effects of repeated heat cycles to wood.

   http://www.doctorfire.com/low_temp_wood1.pdf

   Wood that has been repeatedly subjected to heat has a substantially lower iginition temp that what you would expect. It ain't that much higher than what's required to boil water.

   Therein lies the problem. Tack a 22" wide mantle over a fireplace which if it exists, either you or the next fella is gonna use it, and the heat gets captured. Enuf heat/cool cycles and yer creating the carborized wood situation.

   Bottom line to my advice is the whole scenario has nothing to do with yer "woodbutchery" skills but everything to do with fire codes. The authorities having jurisdiction couldn't and shouldn't, give a hoot whether you've used biscuits before, they just want to ensure a safe installation for not only you, but the next owners as well.

   Besides, a 22" wide mantle is a tad of overkill, simply from a design point of view, and also because of the room space in consumes.

   Anyway, my pea-brained advice is to reconsider this configuration based upon both safety and design considerations.

   Eric in Cowtown