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rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 11:52 am
by MartyNeilan
While in the next phase of disassembly and mods on BART, I discovered that when the hole for the spitvalve was drilled / punched 90 years ago, there is a significant amount of metal that is bent down into the tubing on the inside. I can run my finger through, and it feels like at least 1/16" protruding downward. This is probably causing at least some airflow disruption. What would be the easiest way to smooth this out? The hole is near a bend in the tubing, so I can't easily get at it with a round file.

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 1:05 pm
by Daniel C. Oberloh
A "ball-head" deburring bit (Dremel makes one as well) will do the trick. You go through the vent and use the back side of the bit to clean up the inside edge. simple. :)

Daniel C. Oberloh
Oberloh Woodwind and Brass Works
http://www.oberloh.com" target="_blank

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 1:28 pm
by UDELBR
I was astounded to see this on my high-ticket Hirsbrunner's main slide. :shock:

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 3:25 pm
by UDELBR
goodgigs wrote:OK Joe,Inquiring minds want to know; what's the story behind that photograph ?
My new desktop wallpaper. :lol:

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 4:07 pm
by Rick Oakes
A guess...While in a "dent bag" it was at the bottom of a pile of stuff.

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 4:20 pm
by Rick F
I know what key it's in... it's Be Flat... it really be flat :shock:

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 4:24 pm
by UDELBR
Fixable . . . right? :lol:

Re: rounding out underneath inside of spitvalve hole

Posted: Mon Feb 21, 2011 4:46 pm
by MartyNeilan
bloke wrote:
UncleBeer wrote:Fixable . . . right? :lol:
no brag, but (honestly) I'd give it a shot, if someone offered it to me for $0 - $200.
The piston valveset and rotor seem like they were largely untouched. Maybe with a new bell and leadpipe, and a lot of dent work and annealing on the outer bows, plus one or two small tubing replacements, it might not be too bad.