[TheForge] Re: reducing fuel costs by improving forge efficiency.

Sun Aug 1 19:58:22 EDT 2004

    Hi Frosty,  These considerations on how to build a forge "top/ceiling"
were my
head scratchers as well.  I opted for the Kaowool M board as it is
hard/rigid
enough to span the 16 inches on it's own and provide decent insulation to
the top components of the forge.  The M board however is fragile to falling
long stock that levers up and can break the board.  Using a stock support
seperate of the forge is pretty much mandatory, and puting goal post ends on
it- so parts don't roll off on occassion and add to this hazard. does help.
     I think a ramable refractory like you mention is an excellent idea.  I
also like the domed shape as a totally heat reflective top.  Having never
used the material myself, I don't know what to expect.

     However, I see the picture on Marc Godbout's page of a domed roof with
castable refractory as an insulation and it makes sense to me.  It appears
he used a tank of sorts - and made his ends hinge up for more room to stand
something in his forge. BUT when the lid is considered as a unit, it can be
sealed
around it's perimeter.
    I think I'd leave these ends closed or welded on the domed tank
approach - be it a tank or a barrel with ends - and thus
solve the "sealing the ends" problem when moving in the bricks.  I'd stick
with a
four sided seating to the bricks being in any position and fitting the lid
(without shims and gaskets - as hot bricks are bad enough when reconfiguring
the firebox during use).

    What do you feel the drawbacks to the domed lid (including ends) made
from a tank and refractory would be?
    For your general information, even the lid I make with the rugged angle
iron
construction and stainless components (to the fire exposed sides), and a
3/16
plate lid (for not oil canning/buckling during operation)..........weighs
about 60 lbs with the burners and mounts.

        I'm guessing that Marc's design was worked around a scissors jack
that has
about 6 inches of travel to it.
        For the $28 it costs for the side crank Fulton trailer jack (I'm
using upside down) - with a lifting capacity of 2,000 lbs and about 12
inches
of travel...........I would not be afraid to make my lid weigh a bit more
than my 60 pouner and still be considered very functional.  What would your
guess be on the weight of such a proposed lid - burners and all if made with
refractory?

        A couple more design suggestions to consider during the figuring of
your approach would be:

    1) The burners like mine tend to cascade the flame straight downwards
and out the ends.
        a)this seems like it would work fine for a "full rectangular domed
shape" (tank or barrel style) for sealing the lid on any of four sides.
        b) you would not want to pick up any "exhaust gases" for burner
efficiency due to lack of oxygen defeating your proposed preheat system.
    2) Knowing I move the bricks around and keep the side to the burners
always intact (just varied in height)........ the real question becomes -
where would you draw your heated gasses from  if you needed to keep three
sides available to exhaust gasses (for unlimited adjustability)?
        a) to me the only real option here is to make the top have a "steel
duct/collector" such that would draw off one wall only? (towards the
burners)?
        b) would this actually flow with the curved surfaces of the
lid? or would it create a dead trap of air?

    *This may be a vote for a flat lid(for an easier plenum), but what would
refractory in a flat surface do
when run in that position?

        What are some of the thoughts you have on ducting the preheated air
into your burners?  These thougths could get us onto tangents that might
be workable.

        I guess my overall take of this gas forge I have now is: it works
fairly well with no hot air intake, but I'd be game if we could come up with
a winning design to test something out (as I have two of these in the shop
now - with all the parts for a third on hand).
      I would however like to get rid of the Kaowool M board as the ceiling
for something  more durable.
        My guess is a slightly higher dome, or lid would not really affect
the performance of it's heating ability.

        I tried early on to use exhaust adapters to direct air into the
burners from over the lid on my gas forge as a cheap test, but the flow was
severly restricted and it didn't work well at all.  Your ducting from my
experience needs to be fairly large for the hot air(if your not using a
blower).

    On blowers:
        My friend Paul Morneault built a nice lifting lid forge with clamped
firebrick at the top........it was awesome.  It took him about a month to
build  - but man did it work well.
        His biggest problem in manifolding the air supplies to the burners
down a manifold row, was gate control valves needed to be installed to tune
the burners as the further down the manifold.........the greater the static
pressure - so the first burner roared - where the fourth one barely would
stay lit.....until the valves were made and set.  He had a serious case of
"the least path of resistence" thing going on there at first.

Ralph


----- Original Message -----
From: "Jerry Frost" <frosty at customcpu.com>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Saturday, July 31, 2004 2:18 PM
Subject: Re: [TheForge] Re: reducing fuel costs by improving forge
efficiency.


>
>
>
> > Jerry,
> >
> > A slight dome would help a lot to keeping the kaowool in place. Perhaps
if
> > the blanket is too flimsy, using the board, cut to interlock with a
> > key"stone" would work, especially with the rammable liner.  I have no
idea
> > how much of a curve would be prime, but I bet a slight one would do.
> >
> > Kevin Donahoe
> > Flying Pig Forge
> > Morrow, OH 45152
> > flyinpig at go-concepts.com
> >
>
>
> Doming the lid would help and might even "solve" the "problem" of keeping
> the liners in place.
>
> Unfortunately the nature of the forge's adjustability requires the
sidewalls
> be movable and a domed lid would leak fire when the sidewalls are moved in
> from the perimeter. An inch or so of Kaowool on top of the sidewalls as a
> gasket might do the trick though. I'll keep the idea in mind.
>
> Thanks,
>
> Jerry
> ------------------------
> If it ain't forged
> it ain't real.
> Wrought iron is.
> The FrostWorks
>
> Meadow Lakes, AK.
>
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