Xref: utzoo rec.org.sca:4749 trial.rec.metalworking:20
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From: daveu@sco.COM (Dave Uebele)
Newsgroups: rec.org.sca,trial.rec.metalworking
Subject: Re: Blacksmithing
Message-ID: <7340@scolex.sco.COM>
Date: 2 Aug 90 18:59:13 GMT
References: <7317@scolex.sco.COM> <1828@otc.otca.oz>
Sender: news@sco.COM
Reply-To: daveu@sco.COM (Dave Uebele)
Organization: The Santa Cruz Operation, Inc.
Lines: 76


In article <1828@otc.otca.oz> wayner@otc.otca.oz (Wayne Robinson) writes:
>in article <7317@scolex.sco.COM>, daveu@sco.COM (Dave Uebele) says:
>> Xref: otc rec.org.sca:660 trial.rec.metalworking:10
>> In article <1823@otc.otca.oz> wayner@otc.otca.oz (Wayne Robinson) writes:
>
>May be our problem is that the air flow is restricted as it is and doesn't
>take much slag to block it. Some serious redesign work is in order for
>the forge I am building at the moment.
>	What sort of blower do you use, and what is the diameter of
>the blast pipe on your forges?
>			Wayne


The most common type of blower in use around here is a "Champion" hand
crank blower. I know about 4-6 in use by various smiths. There are also
some older "Buffalo" blowers in use.  The Champion blower has several
brass gears in a cast iron case, the fan shaft ends up below and 90 degrees
skewed from the hand crant shaft.  I've seen fan housings from 8 - 16
inches in diameter. The output hole on the fan is about 3.5 - 4 inches
in diameter.  I think the patent date is around 1902 on the case
of the one I use. The Buffalo blower has several exposed gears and
leather belts and is usually mounted underneath the forge. It usually
has some sort of ratchet mechanism and flywheel operated by a handle
you pump up and down. I'm not sure of the patent date, but I suspect
they are an earlier design, I've seen them listed in the reproduction 1902 Sears
Catalog.

On the forge I have been using (and copying in design for my own forge),
the blower is connected to the forge via a piece of 4 inch metal flexible
duct that would normally be used for a clothes dryer vent.  This attaches
to the stem of a 4 inch diameter cast iron T connection attached to the
bottom of the forge.  One end of the T cross bar goes up to the grate,
the other goes down and has a hinged cover for dumping the ash that falls
through the grate. This may be be what you need, a way to dispose of ash
that falls through your grate so it does not block your airflow.

The grate is piece of .5 inch plate that fits loosely inside the the
pipe. There are several slots cut in it with a cutting torch. It is mounted
on a shaft so you can rotate it to break up small clinkers.

On the forge I'm building, I plan to do away with the the flexible duct work
and just have the stem of the rigid pipe T come out to a fitting where I can
set the blower.

Another thing that might help with welding is to produce a deep fire.
This forge has a fire box that goes about 3 inches below the main
pan. Most of your fire is in the smaller fire box (about 12 inches on
a side). The top pan can be 2 feet square and or larger and have sides
that come up another 3 inches.  You can pile your fuel fairly high this way.
Leave a notch cut out of the top sides on each side of your firebox so you
can get longer pieces into the fire/firebox.  If you are working mostly on
swords, you could make a longer and narrower fire box and forge.

I've also seen forges powered by electric fans, usually small squirrel
cage fans. Some have a rheostat control and others have some kind of 
gate between the fan and the forge. The gate is usually sheet metal or
light plate that slides in and out of a slot cut in the piping.
Look into the gates used with sawdust removal systems used in woodworking.
For any kind of electric fan, I would recommend a foot switch so that
the fan turns off when you turn to the anvil. Saves fuel that way.
If you use a rheostat, often you need to turn it all the way up to get
the fan turning then adjust if to the blast you want. If you have a gate
and a deadman switch then you can keep the same blast adjustment.

Other ideas for forges I'm working on include using the squirrel fan
from an old central heating furnace and rigging it up to a big forge
dug into the ground for tempering anvils. I think the approach I want
there is air volume without too much velocity. I am also thinking of
making a set of leather double chamber bellows that I can attach to my
forge when I want to go more "primitive" than a hand crank. I have plans
for building the bellows, just need to get moving on it.

Sorry about the length of this, hope at least some of it helps.
-- 
Dave Uebele	uunet!sco!daveu  or daveu@sco.com