[Harp-L] On sticking chromatic slides

[Snaruhn@xxxxxxx]

Hi chromaticists,

though the subject is a harp-L evergreen it may be useful to 
talk occasionally about details of this angry phenomenon, 
specially known of the Hohner 270 dinosaurs and similar
models with wooden combs and nailed reedplates.   

Once  I requested Toots  to show me his Mellow Tone but though
it was shortly after his performance the slide was already bombproof
as I had supposed. However,Toots can´t compete with Hendrik
Meurkens, playing exclusively the Hard Boper (that other dinosaur).
Hendrik complaimed that the slide can even stick during his
performance on stage which I`m a witness for.

G. pointed to the weak point which couldn´t be expressed shorter:
                              < the saliva is a glue > 

Yes, absolutely, but in this case it´s important to formulate very 
precisely. It´s not the saliva in toto but only the solved chemical
compounds which act like a glue. This is the crucial point when
examining the following well-known "chromatic rituals":

1. Knocking out the harp after playing. 
2. Warming it up before playing.

Knocking out is absolutely meaningless because the saliva is
spread over the many little surfaces within the mpc of a 270 or
280 and can´t be taken away by simple knocking out. When the
water content of the saliva has evaporated, the glueing effect of
the saliva compounds starts and can only be avoided by
cleaning measures as by warm water as the best method.

Apropos, water. Doug once demonstrated the impressive 
quality of the "Renaissance" by choosing the proper material.
At one SPAH he hold his Renny under a tap and while the
water still dropped out of the cover opening he already played   
it. He couldn´t has done that in case of a wooden comb,
unless sealed by bees wax or the like, or by using paper valves.

I talked with Doug about the glueing saliva and we agreed that one
of the reasons is the slide condition. 

The slide holes are stamped and everybody knows or should
know that the opposite side of stamped or drilled materials
is burred. So, the first measure is to remove these burrs. But
not only the slide burrs. The mpcs of 270/280 chroms consist
of the lower slide plate, the slide, the U-shaped upper slide
plate, and the final profile. All these parts have stamped or
drilled holes and all have to be worked besides the final profile
(it has no contact to the movable slide).

The reason why the burrs have to be removed is to avoid 
scratches on the slide because they act as condensation
points for the saliva glue. Doug´s further idea to additionally
polish the slide I didn´t agree because the surface of 
chrome-plated slides can hardly be improved. 

Instead of, I found another way to prevent the deposition of 
the saliva glue as far as possible. I use trombone oil on all
slide contacting surfaces which simultaneously diminishes
the slide noise.

Warming up harps before playing is as questionable as to
knock them out. I mentioned already in a former post that
the condensation can only be prevented when warming the
harp up to body temperature. This is firstly impossible
and secondly, the inhaled atmospheric air of the 50% draws 
thwarts the warming immediately.

The ideal way to avoid slide sticking is of course not to
blow directly into the mpc but in a detour or to neglect
a slide at all as Vern´s HFC  demonstrates.

Now, Slim wrote:

< I use CX-12s and only need to clean the slides occasionally.>

Yes, it´s typical in the literal sense that the CX 12 slide is almost
insensitive against sticking but this has other reasons than the
different active slide surfaces of straight and crossed layouts.

The slide of a straight 48 chrom has 24 holes, while a crossed 
CX 12 slide has only 13. Both slides are of the same length but 
though the straight holes only measure 60% of the crossed ones,  
the slide surface of the CX 12 susceptible to the saliva glue is
bigger by some 4%, but this small divergence can be neglected.    

This means that the different slide layouts of 270/280/Super 64 /64X
and the CX 12 can´t be the reason of the better CX 12 slide action.
No, it´s the construction of the CX 12 mpc. The CX slide has no
contact to any metal surfaces but only to small plastic crosspieces.

Even when saliva glue would deposit on the slide there´s no 
"partner" for the glue effect and that´s one of the most 
comfortable advantages of the CX 12 though it has some serious
weak points I thoroughly have described in my "CX 12 story".

CXfried
.