bcFour wrote: ↑Wed Apr 29, 2020 12:33 pm
@dw , I was following that conversation on the other forum and have been interested in the results. A few questions:
- The migration of cork doesn't seem like a horrible thing. In essence, its movement away from pressure points would accentuate the effects of the footbed taking the shape? no?
- A positive of cork is how easily it is to shape and rasp down to the proper shape and level with the welting. How is this achieved with the Irish Flax?
Having never used the Irish flax, but hearing your (and others) rave about it - I'm really jonesin to give it a try!
thanks,
bob
Just my opinion, albeit after near 50 years of experience: It doesn't take much pressure at all to make the cork break up / disintegrate into the constituent particles (mostly no larger than 0.125" x 0.125"). It is the loose particles that migrate...mostly to the waist. I have opened shoes that were originally filled with cork and found nothing under the forepart...just bare insole...and then pulled the shoe off the jack and had a couple tablespoons or more of loose cork come spilling out of the waist. So there was no footbed mitigation whatsoever---wasn't any cork under the footbed, at all.
But the real problem with cork, as I said, is that it is fundamentally occlusive. It prevents the insole...given that the insole is leather at all...from breathing. Simply because the cement used to mount the cork seals the fleshside of the insole.
Some makers aren't concerned by this...whether it is because they don't understand, or see, the need for the insole to breathe; or because they don't know any other way; (and it's too much effort to learn); or because they don't believe, or want to believe, that a .5+ mm seal of neoprene is a significant barrier to moisture wicking away from the foot, I can't say. But it has been a major, decades long, undercurrent in my career to not only eliminate as many of these occlusive procedures as I can but, in my work, to dispense with the
need for petro-chemical based cements, as much as possible. Not good for the planet, not good for me.
Much of that comes down to rediscovering (at least for me) older procedures that relied on paste--at one point in time there were no All Purpose cements yet very fine quality shoes were made. Go figure.
As for trimming the Irish Flax Felt...the real issue is trimming the welt and inseam. The felt is thin enough that if there is no significant gap 'hollow' from one feather to the other, the felt just needs to fit in-between...no trimming, rasping, skiving, etc., needed. And I suspect...maybe
@das could weigh in on whether this was a common practice...if more fill is needed, another layer could be added.