ThomTapp
member
Reged: 01/18/11
Loc: Kingston TN
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Pitch
#5624195 - 01/15/13 11:09 AM
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Where do you get your pitch? Haven't bought any since the 80's and it seems to be very expensive now...
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gpelf
super member
Reged: 12/28/11
Loc: Kentucky
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Re: Pitch
[Re: ThomTapp]
#5624202 - 01/15/13 11:14 AM
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Hi Thomtapp,
The most common places I know of are: Got Grit and Williman Bell....
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gpelf
super member
Reged: 12/28/11
Loc: Kentucky
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Re: Pitch
[Re: gpelf]
#5624205 - 01/15/13 11:15 AM
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Oh yea, There is also Acculap which is a synthetic pitch.
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Pinbout
Post Laureate
   
Reged: 02/22/10
Loc: Montclair
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Re: Pitch
[Re: ThomTapp]
#5624275 - 01/15/13 12:02 PM
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firsthanddiscovery
stay away from acculap...
the black stuff is so much nicer to work with.
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ed_turco
Pooh-Bah
   
Reged: 08/29/09
Loc: Lincoln, RI
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Re: Pitch
[Re: Pinbout]
#5624506 - 01/15/13 02:18 PM
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I have had a very very bad experience with W_B with pitch for my telescope group. I'd try the other outfits.
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Norm Meyer
super member
   
Reged: 02/08/09
Loc: Warren, ME 04864
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Re: Pitch
[Re: ed_turco]
#5624582 - 01/15/13 02:54 PM
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ThomTapp, I've used both Gugolz and Burgundy pitch. Years ago everyone was recommending Gugolz so I switched. Then at Stellafane Bob Royce gave a talk on telescope making and he said he used Burgundy and saw no problem with it. The last batch of Burgundy tempered pitch I received from WB seems to be a bit softer than previous batches. This has worked to my advantage. My basement in the winter without the wood stove going the temp is about66 deg F. This softer pitch has been working great with the cooler temps. I presently am figuring a 6" F12 mirror and I have almost finished it with burgundy pitch. To say one type of pitch is always better than another is not true. Everything must be taken into account temperature, humidity temper of the pitch,etc. You have to "feel" how the pitch is reacting and adjust accordingly. The lap I am presently using would be too soft in the summertime. I used to wait until warm weather to figure. Some of my best mirrors were figured in the summer and now I know why, the pitch was a little harder and didn't flow as well. Everyone has different techniques they don't all work the same for everyone. There is some "art" along with the science. We can teach you the science but the art comes through experience.
my $0.02 worth
Norm
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mark cowan
Vendor (Veritas Optics)
   
Reged: 06/03/05
Loc: salem, OR
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Re: Pitch
[Re: Norm Meyer]
#5625701 - 01/16/13 06:56 AM
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Some of my best mirrors were figured in the summer and now I know why, the pitch was a little harder and didn't flow as well.
That doesn't sound quite right...
Best, Mark
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kfrederick
Carpal Tunnel
Reged: 02/01/08
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Re: Pitch
[Re: mark cowan]
#5625710 - 01/16/13 07:20 AM
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I polished out a mirror with very soft pitch[ dent your nail in one second] it was on the matching tool maybe only 1/8 thick It did not need triming and poished nice . I like very hard pitch with window screen pressed in . If you do not have the pitch on a matching tool make sure it is thick . I have a pitch mat it is only 12inches square but it works great perfect one inch squares no mess .Hard pitch tempered with motor oil will stay the same hardness for a long time .
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Norm Meyer
super member
   
Reged: 02/08/09
Loc: Warren, ME 04864
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Re: Pitch
[Re: kfrederick]
#5625831 - 01/16/13 09:19 AM
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Mark, You're right I meant to say the pitch didn't flow as well in the winter when the basement was cooler.
Norm
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jblockyou
super member
Reged: 07/19/10
Loc: Divernon Illinois
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Re: Pitch
[Re: Norm Meyer]
#5626409 - 01/16/13 03:36 PM
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I use Acculap exclusively and I get it from Salem Distributing. Works great. Hardly no smell.
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sopticals
sage
Reged: 03/28/10
Loc: New Zealand
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Re: Pitch
[Re: mark cowan]
#5626846 - 01/16/13 07:35 PM
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Quote:
Quote:
Some of my best mirrors were figured in the summer and now I know why, the pitch was a little harder and didn't flow as well.
That doesn't sound quite right...
Best, Mark
+1
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sopticals
sage
Reged: 03/28/10
Loc: New Zealand
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Re: Pitch
[Re: kfrederick]
#5626872 - 01/16/13 07:48 PM
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Quote:
.Hard pitch tempered with motor oil will stay the same hardness for a long time .
The motor oil thing didnt work for me. I added a quantity of motor oil to my pitch when molten, and it seemed to mix ok, BUT when the mix cooled the motor oil separated out from my Gugolz pitch leaving the pitch as hard as ever. I use "Stockholm Tar", (a soft runny pich used as an animal remedy,easily obtained trom a veterinarian shop.) as the softening additive.(Perfect , and softeness of the lap is maintained long term, unlike a pitch softened with pure turps or the like.)
Stephen.(44deg.S.)
Edited by sopticals (01/16/13 07:49 PM)
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ed_turco
Pooh-Bah
   
Reged: 08/29/09
Loc: Lincoln, RI
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Re: Pitch
[Re: jblockyou]
#5627085 - 01/16/13 09:51 PM
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No smell? The smell is what I live for, and when my polishing is going right, I get faint a pitchy aroma from my lap.
Then I know I have things going well, and the sweetness of the pull in stroking is something to be desired.
Ed
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Norm Meyer
super member
   
Reged: 02/08/09
Loc: Warren, ME 04864
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Re: Pitch
[Re: ed_turco]
#5628060 - 01/17/13 01:01 PM
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Sopticals,
Mark was right I misspoke but I corrected in a subsequent post.
Norm
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kfrederick
Carpal Tunnel
Reged: 02/01/08
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Re: Pitch
[Re: ed_turco]
#5628066 - 01/17/13 01:06 PM
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Turco are you sure you are talking about making mirrors or kids . Ha Ha I know what you are saying . Your passion for polishing is cool
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Pinbout
Post Laureate
   
Reged: 02/22/10
Loc: Montclair
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Re: Pitch
[Re: jblockyou]
#5628143 - 01/17/13 01:55 PM
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Quote:
Hardly no smell.
acculap has a smell, use a soldering iron to open up the channels. my wife complains about.
gugolz smells so much nicer.
I like the smell of gugloz in the morning...it smells like success.
I like the way gugolz melts way better than acculap. acculap turn to water way too fast.
and when you recycle acculap and all the styrene turns into little white balls you have to filter out.
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jblockyou
super member
Reged: 07/19/10
Loc: Divernon Illinois
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Re: Pitch
[Re: Pinbout]
#5628316 - 01/17/13 03:31 PM
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I do not melt the channels so I don't get a smell, and because of the way I make the lap, I can use each lap on about five mirrors and remove the pitch and throw it away. When I used to recycle the pitch, I never did get styrene in little white balls, but once I did get resonated chloride which formed in a hexagonal tubular shape with a small hook on the end.
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ccaissie
sage
Reged: 09/13/10
Loc: Whitefield, Maine
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Re: Pitch
[Re: Norm Meyer]
#5629039 - 01/17/13 10:44 PM
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Norm:
Did I ever give you any of Brower's pitch? I've used his recipe for a decade now and really like it...Burgundy, Rosin and Talc. Soft, but stiff, and holds its shape when machine polishing.
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