Roderick Welch: Arts, Craft and Design

Felt Hardener

You can use the rollers at anytime during the felting process after the wool has become felt. (some use them at the beginning of the process also but I would not recommend it,)We use them mostly at the end and also after rinsing, when the felt is still damp, to even up any soft spots or to make it harder all over... The change is surprisingly rapid.
Perfect for hardening up uneven areas of your felt roll while it is still running on the machine...

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Pictures during early development

The hardeners came about after seeing an industrial felt "hardener" in action about 3 or 4 years ago...
The working surface of the machine has a thick rubber mat on it. (like conveyor web, really heavy...) The machine comes in different widths, and there are three, full width, laterally ribbed, metal rollers, about 6 or 7 cm in diameter, suspended on a "frame", a couple of inches above the surface.
You put your felt (Valenki, rug, whatever, as long as it is tough...) on the rubber mat, turn on the machine and stand well back. The "frame" is part of an hydraulic ram system that clamps the rollers down onto the felt (or your fingers if you are not careful) and then moves the rollers back and forth (about 18 inches) at quite a speed.
The idea is to allow it to work on one part of the felt, then change position, and let it work another area until you've covered the whole felt. As you have to hang onto the other end of your felt while it's working there is no front guard on the working surface of the machine. I don't know if they are still made or even legal in a workplace but they are very effective... (just don't misjudge the distance the rollers travel)

Anyway we decided we needed something like that at home so I started a few experiments... My first thought was to make a mechanical, "soft and gentle" version that worked with a crank and a hand turned wheel. The problem was applying enough downward pressure to the rollers and after making the "roller frame" I shelved the rest because of time and money...
The frame holds three, 4 inch diameter wooden rollers about 60cm wide. It has cast iron ends for extra weight and the outer two rollers are "sprung" so they have a bit of "give" and you can get a bit of a rocking action going when in use... It worked wonderfully for final hardening of thick felts but it was so heavy it could only be used by two people really... (or a body builder)
I made a second design that also had three rollers, (above illustration) much smaller, (about 12 x 10 inches) with a double handle, (one armed, repetitive actions = one arm RSI...) using thick metal framing for extra weight, (just moving a heavy object back and forth is a lot less strain than pushing down on it at the same time...) and also had some ideas about wedging a bamboo between it and the ceiling for extra pressure. (don't laugh, just ask a wooden boat builder...) but in the end, as with all things, simple is best...

So, "THE" most effective solution was a single roller, easy to use, store and the most flexible...
It means you can get a lot of pressure in a very small area. As soon as you have multiple rollers any pressure you put on is divided... (18 wheelers... imagine there was only 4...)

With a single roller it means you can really focus on one spot and bring it up hardness... We make "thick" felts so I'm not sure what use they would be for lightweight or thin material... I find that light/thin felt is easier to work (you can scrunch it up and throw it around...) and doesn't need any extra tooling... I don't know??
In the course of all this (including building our felting machine) I discovered that making felt means making irregular and random movements and patterns. Any regular or constant pattern or movement results in uneven felting... (that doesn't sound right... but I think it is true...)

Any tooling I try to make work in the most irregular way possible, so the rollers have an asymmetrical rib pattern etc.
Our roller/hardeners have a 20cm to 70cm working surface (plus 20cm for the handles) and are 8cm to 10cm in diameter... They are hand-turned using solid Finnish Birch and the grooves (about 10 on a 8cm roller and 13 on a 9cm and so on...) are cut at random intervals, up to 1cm wide and 5mm to 8mm deep.
The reason for cutting the grooves like this is apparent when you use the roller. Narrow, regular grooves and ridges pass evenly and smoothly over the surface of the felt with little or no vibration. The felting action is in the vibrating action, (vibration equals feltation!!) the more movement you can produce, (within reason) the more effective the hardening process.

Feltmaking is a very ancient working technique. I think any mechanical aids should try to imitate the "traditional" or "original" forces and techniques that go into it.... a camel and a piece of steppe, 12 people with nothing else to do all day except "kick" felt etc. etc...
Felt "power tools" are all a compromise really, so haphazard and random are the watchwords... and speed... think of how slowly everything and everyone used to move... If you think, all pre-industrial tooling and equipment was cut by hand, things that didn't need to be "flawless" were not made so... now it is more expensive and time consuming to make something "irregular" than it is to make something perfectly constant. (relatively speaking)