SP 20 comb
Hi Kinya, have you ever played with shrinking the comb on SP 20's to tighten up the sealing edges ?
Hi Kinya, sorry for taking so long to reply but it has been lambing time so been busy. I have been trying to control the shrinkage with time at temp and what temperature . The temperature of the water has been between 185^f and 225^f , I just place the harp (without the covers on it) in a container of clean water (not city water) and heat. The nice thing about copper alloys is that they are not sensitive to temperature so no damage done to the reeds. But anyhow it looks like 2% shrinkage of the comb is the way as I have gone as far 5-6% but the comb cracks at the 6 hole within a month or three (looks like the post that support the covers sets up stress). Also I was wondering if you new what plastic the comb is made from?
Yikes!
This IS intriguing ... "but hold on a minute", my brain is telling me ...
The Special 20 combs are some of the most true (flat), and therefore, air tight harmonica combs in the world. The close tolerances between the mating surfaces between the comb and reed plates will ensure each chamber (slot) is air tight. Of course, there is the wiggle jiggle gap surrounding the perimeter of the reed plate--as you index them--but that becomes irrelevant once you tighten the reed plate bolts...
So I am perplexed on the advantages of this shrinking comb strategy. Tom, have you found a discernible improvement in the performance of your harmonicas?
... maybe I will try it.
~Kinya
Hey Tom,
I forgot to mention, the SP20 injection molded combs are made of ABS plastic (Acrylonitrile-Butadien-Styrene).
~Kinya
Hi Kinya, this is just something that I noticed when cleaning my harps. I now remove the reed plates and clean them with out comb. But the shrinking does take all of the sharp edges off in one easy step. The way I clean is in Cleaning solutions thread.
MX
So what's stopping me from trying this ... right?
Hello MX,
No, but I'm intrigued. How do you do it?
~Kinya