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Maarten van Weverwijk
Heavyweight Member
Joined: 04 Jan 2006
Posts: 2509
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 Posted: Fri Nov 06, 2009 7:57 am Post subject: |
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Brian,
Not often I disagree with you, but for this purpose 400 grit sandpaper is not really fine at all and still VERY abrasive.
Personally I wouldn't use any rougher than 800 and for final polishing even 1200 or 2000.
MvW. |
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Ed Lee
Heavyweight Member
Joined: 14 Aug 2009
Posts: 1429
Location: Jackson NC 27845
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| Posted: Fri Nov 06, 2009 8:09 am Post subject: |
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First, ultrasound high frequencies will dissolve most lacquers! Copper, brass, and bronze ALL "age" in air developing first a greenish patina edged with a whitish crust (cuprous sulfate) and then subquently draw arsenic out of the air turning blackish (cupric arsenate). The dust generated from the first isn't so hazardous, but the second is. It will even permeate your flesh.
The inside of your leadpipe is a tapered bore. There are as many different bores as there are makes and models of horns plus the many after market products. If only we had the precise bore that produced our leadpipe, manual twirls of this should clear our pipe to its original condition, but, alas, we don't and techs don't.
As for the brass gun brush ... you're scratching and accelerating areas that will more rapidly develop more of the problem you're attempting to now address.
Flushes? If the product label reads poison or hazard, why risk your health handling it?
Well, the only method I've seen my techs use is spring mounted micro hones. Certainly any usage of a scraping procedure may alter sound.
As for visual inspection, tool suppliers now offer fiber optic viewng scopes, high end models providing powerful magnification and interface with digitation for computerized modeling and CNC operations.
I do recommend a light oil swab, not only of the leadpipe, but the whole horn from time to time.
Ed Lee |
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shofarguy
Heavyweight Member
Joined: 18 Sep 2007
Posts: 2352
Location: Glendora, CA
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| Posted: Fri Nov 06, 2009 4:47 pm Post subject: |
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| Maarten van Weverwijk wrote: | Brian,
Not often I disagree with you, but for this purpose 400 grit sandpaper is not really fine at all and still VERY abrasive.
Personally I wouldn't use any rougher than 800 and for final polishing even 1200 or 2000.
MvW. |
Okay, Maarten, you win. 800 grit would be better. In my case, though, I used 400 because it is readily available and required only a few swipes to get the last bits of calcium off and put a nice smooth finish on the inside of the pipe.
For me, I know that 800 or 1200 would take enough time that I'd be tempted to wrap the stuff around a 1/4" dowel and spin it in a cordless drill! I think that that would give more inconsistant results than a light brushing and a quick smoothing with the 400.
I know that polishing the mouthpipe is supposed to be a good thing, but I could not find any degradation in the playability of my Benge from lightly using the slightly coarser paper.
Everyone! Use 800 grit paper or finer, if you go that route.
Brian
_________________
Flip Oakes Wild Thing Bb Trumpet
Flip Oakes Wild Thing Flugelhorn
LA Benge 5X
There is one reason that I practice: to be ready at the downbeat when the final trumpet sounds. |
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jhatpro
Heavyweight Member
Joined: 17 Mar 2002
Posts: 6138
Location: Chicago area
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| Posted: Fri Nov 06, 2009 6:20 pm Post subject: |
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The gun bore brush I used is fiber, not metal. It doesn't scratch. As I mentioned earlier, the CLR worked great - just two minutes. And I swabbed it with one of Tim Wendt's chamois swabs, and added some oil so I think I'm in good shape from here on out.
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"Stay thirsty, my friends!" |
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Maarten van Weverwijk
Heavyweight Member
Joined: 04 Jan 2006
Posts: 2509
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| Posted: Sat Nov 07, 2009 12:56 am Post subject: |
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| shofarguy wrote: | | ...I used 400 because it is readily available... |
Brian,
About the availability of smaller grit, this might help you out:
My source for sandpaper, micro files and other abrasive stuff is "Otto Frei" in Oakland.
They sell 3-M paper up to 8000 grit (meant for polishing lenses) and also sell tiny split mandrels that come in handy when polishing inside of a tube shaped object.
Admittedly I very rarely use anything finer than 1200 grit, though I have 1500, 2500 and 4000 paper too. Finer than 1500 is pretty useless for us; the rather soft brass particles tend to quickly congest ultra fine paper. For real polishing I prefer to use red rouge or one of the readily available liquid products.
Here's the address: http://www.ottofrei.com/store/home.php?cat=817
Sorry for the bend-off, Jim!
MvW. |
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