You have lost me completely. The board is the limiting factor,
OP stated it was 2" thick. Biggest all thread I would attempt
would be 1 1/4". 3/4 all thread would probably suffice just fine.
The stuff is available in many sizes and alloys ( the 2" and 4"
diameters would be difficult to use in his board):
http://coburnmyers.thomasnet.com/vie...rod?&forward=1
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"RayV" wrote in message
ups.com...
DanG wrote:
Install the rods (all thread works well) in the wood. Bend the
rods as required to insure they are square and true - this
should
not be necessary if you use care on the drilled holes. Drill
oversized holes in the masonry, install epoxy screens or
umbrellas, and epoxy. You will need to brace and carry the
mantle
while the epoxy sets up. Here is what I use:
http://www.ramset-redhead.com/RH/rh_aas_intro.asp


Your technique sounds like a good and easy to execute plan
except for
the all thread. The OP stated the wood is 18" wide. I think
the all
thread would bend unless the fireplace had a smooth surface like
brick
for the shelf to press against. Maybe some rebar if you can get
it as
thin as the mortar joints, still bendable but not as flexible as
all
thread. Maybe drilling the hole for the rods near the top of
the shelf
so bottom portion could press against the wall preventing the
rods from
bending. Overall good plan of attack.

shelf rod
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