Re: [Harp-L] deburring slide

[Joseph Leone <3n037@xxxxxxxxxxx>]

On Apr 21, 2014, at 1:08 PM, Music Cal wrote:

> Smo-joe
> 
> What do you use to jewel the edges of the air holes?
> 
> Not-smo-joe
> 
> 
Ok, most stamped parts have burrs. As the die cuts through the material, the entry point is usually ok, and if you looked at it in cross section, you would see the edges of the entry point are ever so slightly rounded. The older the die, the more the rounding. Think cheese. Even with a very sharp knife, as you press on the cheese, you will notice that the blade presses into the cheese before it starts to shear the cheese. You are left with a soft edge. BUT the bottom will be more ragged. Same thing with a slide.

So, take your slide and run your fingers across it  lengthwise and notice that while the (usually) top seems ok, the bottom has some drag to it. You should remove that. Now working over a piece of white paper, holding the slide in your hand, take an exacto knife, and starting at the very corners of the 40/48/56/64 holes, scrape the blade gently and at a 45 degree angle to the edges of the sides of the holes. First do the left sides, then the right, then the tops, then the bottoms. In other words do all the edges. But do it in a way that you do one set of edges at a time and count as you go so as to do ALL the edges and not forget any. That will be 160/192/224/256 edges. You will see micro fine particles on the paper. 

There are other things you can use. Like wooden coffee stirs which have been coated (dipped, glued) with emory paper or powder. OR split down emory boards, OR an ignition points file (getting rare), and yada yada so on. Then you can, as Vern suggests, use a crocus cloth. Since the pads of our fingers are relatively soft, any time we rub something using the tips of our fingers, these pads will tend to dip or depress into any deformities. So as you rub your work, the edges will be 'eased' or the edges 'broken..in machinists parlance', and you no longer have burrs. 

I like to classify abrading tools and materials into what I call MOHs scales. This scale means 'hardness'. I give abraders numbers like:
10 = grinder
8=    file
6=    sandpapers
4=    grits (emory, etc)
2=    pumice (Lava soap, etc)
1=    polishes (Brasso, crocus, silver creme)
0=    water

And of course the numbers I skipped would be filled by materials that were in between..so to speak. Another thing to consider are the top 2 edges of the slide. Since they are also sharp and the inside of the U channel is NOT, you could ease those edges too. That way you don't have your slide slicing into the bent over edges of the U channel on the inside and causing drag. And since drag IS a drag, I like (as Vern puts it), a buttery slide. I always finish the job with either Bruce or Johnson's paste hardwood floor wax. Used sparingly and rubbed in good.

I like to carry 3 small eyedrops bottles of fluids. 1.. whale oil. 2 .. water. 3 .. alcohol. Last night one of my chromatics was a bit sticky and I only had to apply a teensie (that's teensie) amount of alcohol to 3 spots on the slide (and the spring end), and It was enough to slick up the mechanism just fine. What it does is re-jeuvinate the micro fine wax coating. As I have said many times. If you don't learn to work on your own harmonicas, it could cost you a small fortune to play them. There are a ton of things a body can do with a chromatic. And you don't have to have a shop in the 5 figure range to do it. 

And Me? Personally? I would take any and all advice from Vern Smith ...TO the bank. The kid knows of which he speaks. 

hope this helps. 
smokey-joe