Bruce Thacker writes:
>At present I am trying to figure out exactly how the #95 butt
>gauge was used. Mine is a "Type 2" so it couldn't be used as a sm.
>square. If anyone can enlighten me, please do.
Ah, yes-- a marking gage question! My day is now
complete... ;-)
I'm a big fan of the #95-- It's an incredibly handy tool
for hinge mortises, and it makes a swell marking gage as
well. Add to this the fact that they're dirt cheap, and
you've got a tool that should be in every galoot's set.
Setting it up is quite straightforward, but not intuitively
obvious. Once you understand the basics, however, it's
clear.
Consider the following to be butt gages 101: ;-)
[quoting from my Gage Page]
The butt gage is a specialization of the marking gage
which is designed for marking mortises for butt hinges.
This is a surprisingly complicated job with little room
for error-- if the hinges are not properly placed, the
door may not work properly (or at all).
There are two common situations encountered in butt
mortising-- one in which the door is being fitted into a
rabbeted jamb, and one in which the strike for the door is
nailed on. In each situation, the marking job is slightly
different.
In the case of a rabbeted jamb, the most important thing
is to mark the hinges such that a small gap (usually
1/16") exists between the face of the door and the back
of the rabbet. If this gap is not present, the door will
bind. Butt gages designed for this situation will mark a
specific distance from the corner of the rabbet, and a
corresponding distance (minus the desired gap) from the
face of the door.
[snip]
In the case of a nailed-on strike, the job is much
simpler. Since the strike is added later, there is no
need to account for the gap between the strike and the
door. In this situation the hinge depth is marked
referencing the outside of the jamb and the corresponding
side of the door, so the door will be flush with the
jamb.
[end quoting]
The #95 is designed for the first scenario-- marking for
a rabbeted jamb. The #95 has two arms: one with a single
point, and one with two points. The single point arm is
used to mark hinge thickness (nothing fancy there). It's
the two-point arm that does the interesting work.
If you look carefully at the two-point arm, you will notice
that it has this general layout:
/|___________________
|___________________ |
\|
The important thing to notice is that one point is bevelled
on the inside and one on the outside. Now if we look at
the arm as used in the #95, we have:
-A--
__/|______________
| |____
| |___ |
| | |/
| |-B-
|__________________|
Since the arm is exactly the same length as the body of
the gage, you can see that the distance A is greater
than the distance B by the thickness of the scribe.
This is the clearance distance for the door.
To use the #95, you would mark distance A referencing the
side of the rabbet in the door jamb, distance B referencing
the outside face of the door, and (as Jeff would say) "Bob's
your uncle!"
Hope this clarifies things. I'd be happy to answer any
further questions. I'd also be willing to write up Butt
Gages 102 and maybe even Butt Gages 200 if there's any
interest. I have to draw the line at Butt Gages 400
(setting up a #92 for mortising), though... ;-)
ralph
============================================================
Ralph Brendler (ENB/FOYBIPO/OTLM) Chicago, IL
Woodworker and Collector of Antique Marking Gages
http://www.mcs.net/~brendler/oldtools
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