The all new Weickert felt hammer by Ronsen

[David C. Stanwood]

Hi Dale

Didn't catch the word "pre" when you mentioned pressing..., Just 
wanted to make a positive point to the readership about coldish 
pressed hammers which is that the tensioning of the felt is not lost 
as in a hot pressed hammers.   This tensioning of the fibers gives a 
kind of resiliency to the felt which makes it very bouncy like a 
superball... remember them?  The kind of heat that most production 
hammers are made with erases this magical quality.  I believe that 
the special kind of tensioning found in lukewarm pressed hammers 
contributes greatly to their beauty.

The starting point for a heat level that starts to degrade the cold 
pressed quality is a little "fuzzy".   The quickest way to check is 
to steam a spare hammer and if it expands at all, then it technically 
has density made by hot pressing which greatly reduces resilience... 
The most resilient felt builds density by intertangling (felting) of 
the fibers.  It's a little confusing because there are two ways of 
building density in a hammer, one by making the felt dense enough 
before stretching around the molding then the stretching itself 
builds density....

The buffing wheel felts are not hot pressed just hard by felting with 
very high pressure... the fibers just ratchet together to a very high 
density... amazing really...

The amount of natural felting that occurs during felt production is 
very critical.  Too much and the felt will tear, too little and the 
tensioning slips and the hammer is too soft...  The art of producing 
a great cold pressed hammer is really linked with the art of making 
great hammer felt.

My hat is always gratefully off to Ray Negron and Jack Brand (and his 
highly skilled feltmakers in Wurzen Germany).  It would be a very 
different world without you both!

Best TY,

David

"Take a sheep to lunch"


>David
>I agree. A loss of resilience occurs in Pre pressing, which is the practice
>of pushing the felt into the caul before the underfelt is laid in,to crease
>the felt in the middle. The purpose of this is so it is easier/possible to
>center the underfelt all along the length of the  felt strip in the 
>final pressing.
>Pre-pressing or pres-stretching  is more often over done & it is this process
>where the felts ability to be tenisoned is reduced. I believe every 
>maker  pre-presses
>to one degree or another but pre pressing should be kept to a minimum, just
>enough ot crease the felt slightly so the underfelt can stay centered with the
>final press happens This is the the case with Ronsen hammers.
>Technically there are no Cold pressed hammers. There is always so heat present
>to cure the glue.  Something like 130 degrees when the felt is 
>pressed in & then
>it's turned off. Ronsen hammers stay in the press 3 hours after the 
>heat is turned
>off.  Other hammer makers whiz them in & out of the press using far 
>more heat to
>cure the glue faster. Of course this aids production but the hamners 
>are losing resilince, >tension & compression under this protcol.  I 
>think this is the way buffing wheels are made.
>LOL
>Dale


>>Dale,

>>I've always felt (no pun intended) that tension in a cold pressed 
>>hammer develops
>>resiliency and density at the same time and that this tension is 
>>always diminished
>>by hot pressing. Imaging bouncing something off a stretched nylon 
>>rope... (nylon
>>being very stretchy). If the rope isn't stretched tightly you can't 
>>bounce off it
>>very well...?

>>David S

>>>Dale Wrote: <snip> Pressure is pressure but pre pressing removes
>>>resilience as does too much heat. <snip>