[TheForge] Holdfast

[Peter Fels & Phoebe Palmer]

There was discourse on Anvilfire.com about this subject.
It turns out the critical part is the ratio of horizontal to vertical 
elements ( 7 to 1?) and the angle of the bend ( considerably tighter 
than 90*).
The shank needs to relate to the size of the hole and it helps to 
roughen the shank on the inside of the bend side.
Release is , either smack the angle opposite the bend or strike the 
bottom of the shank.
Vague memory of a good pic of one on the Acorn site.

Mike Spencer wrote:
>> I have been trying to make a holdfast for doing hot cutting. I have
>> the shape right (I think) but I am having trouble. 
> 
> The holdfast is a great idea.  I have made one each of every type I
> seen or read about.  None of them work. I must be a moron or something.
> 
>> The darn thing won't stay in the the hardie hole.
> 
> Just so.
> 
>> ...the Holdfast EJECTED itself up a good two feet in the air.
> 
> Been there, done that.
> 
> My solution, stolen in part, IIRC, from Pat Comstock, is a chain
> holdfast.
> 
>       + 2' piece of 3/4" plywood or a board
> 
>       + Eyebolt near one end of the board
> 
>       + Bicycle or motorcycle roller chain attached to the eyebolt
> 
>       + Carabiner or similar on the other end of the chain
> 
>       + Hook or eyebolt on the off side of the anvil block on to which
>         the chain can be snapped.
> 
> Board sits on the floor on the nigh side of the anvil like a treadle,
> The chain goes over the anvil to the hook.  Put the workpiece under
> the chain and stand on the treadle.
> 
> A further refinement is to put a few links of 1/8" ordinary chain on
> the treadle end of the roller chain and a keyhole plate on the
> treadle's eyebolt.  Then the treadle height can be adjusted to
> accommodate a larger piece of stock that would otherwise make the
> treadle too high for good hammering posture.
> 
> Some people use a stirrup instead of a board/treadle but then they
> spend several seconds trying to get their boot into the stirrup.
> The board is better.
> 
> When not in use, unsnap from the stump and hang on the tool rack.
> 
> 
> FWIW,
> - Mike
>