[ATM] tile tool

Wed Mar 30 02:46:28 JST 2011

At this year's MidAtlantic Mirror Making Weekend #11 we had the time frame of Friday Noon to Sunday afternoon to fine grind, polish and figure our mirrors...there is no time allowed for UH-OH's.

Over the years we have fine-tuned our recipe that resulted in 16 of 19 mirrors being finished Mar 11-13, 2011.  The 3 that did not finish were:

1) the mirror maker quit...decided mirror making was not what it was cracked up to be
2) the mirror maker had to leave early due to an emergency
3) a 16.5" that we did not expect to finish in the given time frame because the mirror maker went back to 80 grit.

The 16 mirrors that were finished were excellent...fully polished, fine figured, no chips, sleeks, or scratches...we finished 3-6", 5-8", 4-10", 3-12.5" and 1-14".  All were figured to a null on either a Ross-Null or Double Pass Auto Collimation setup.

Our experience in previous sessions have been just as good or better...MMM#'s 9 & 10 everyone finished.

OH...I almost forgot...MMM is an all-volunteer effort.  The talent and time devoted to this one weekend is truly awesome.

I suppose what we are discussing here is the "art" of mirror making vs science.  We all know there are many paths to a fine finished and figured mirror and every mirror maker will instinctively take his own path.  That's what makes our hobby interesting.

More grinding, more polishing, and a lot more figuring...then put those mirrors in scopes so that you can really appreciate mirror making.

Don...

On Mar 29, 2011, at 11:53 AM, Richard wrote:

> Under no circumstances should deviation be tolerated in a mirror making
> class.   Deviant behavior can be contagious, so deviants must be expelled
> immediately.   Deviancy constitutes disrespect of AUTHORITY and can not be
> tolerated.   Biblical support for this is found in Romans 13.
> 
> 
> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
> Mel Bartels
> Sent: Monday, March 28, 2011 8:19 PM
> To: atm at atmlist.net
> Subject: Re: [ATM] tile tool
> 
> Glass tools cost money, they can scratch badly, they're slower than ring
> tools followed by plaster and tile tools, they don't do as good as job in
> removing anomalous pits at the end of fine grinding, first time mirror
> makers often accidently let the final aluminum oxide dry out freezing the
> tool and mirror together and they are disastrous on large thin mirrors.
> 
> During our last mirror making class, we churned out a number of plaster
> tools in an evening. I don't know where you got the idea that plaster tools
> swell - it doesn't.
> 
> If you have a procedure for your mirror making classes, then by all means,
> don't deviate. I have a procedure which works nicely too, thank you!
> 
> Mel Bartels
> 
> 
> 
>>>> 
> maybe it is possible to make a satisfactory tool from these materials...but
> along with the stories about making and using them are stories of scratches,
> sleeks, broken tools, missing tiles...the list goes on and on.
> 
> when we consider the number of hours we put into making a high quality
> newtonian mirror why would we want to save a dollar or two on a tool and
> increase the risk failure of the project?
> 
> at our MidAtlantic Mirror Making Weekends we use plate glass tools the same
> size as the mirror.  They really aren't as expensive as you might have been
> led to believe especially if you use them to make more than one mirror.
> maintaining a good smooth bevel on tool and mirror has eliminated scratches
> and sleeks at MMM's.
> 
> plate glass is dependable...no tiles to break loose, no rust, no concrete to
> spall, no plaster to swell...it just makes sense to begin a project with the
> least possibilities for failure.
> 
> Plate glass is available from Swift Glass and NewPort Glass...maybe others.
> Oh, I have no affiliation with any glass company.
> 
> Don...
> 
> 
> On Mar 28, 2011, at 10:40 PM, Mike Coslo wrote:
> 
>> On 3/28/2011 5:15 PM, Jerry Hillman wrote:
>>> I know this has been answered but when I tried to find it in the archives
> I came up with 100's of posts about tile tools.  I can't find what I need.
>>> The tile tool that was supplied with my mirror blank was made with
> textured tiles.  After two hours of grinding the glaze is coming off the
> tiles in the center but I can still see the texture everywhere else.  Is
> this a problem or should I throw it away and make a new tool. Or continue as
> i am until all the roughness is ground off. I am worried that I will destroy
> the curve.
>>> Jerry B.
>> You're going to get a lot of replies about this, but here's one from a guy
> that is totally wrong.
>> 
>> There is no way that I would use glazed tiles for a tile tool. porcelain
> is the only way I roll.
>> 
>> There are some reasons for this - also wrong.
>> 
>> 1. Basic tiles are quite soft. They wear quickly. I can't think of a good
> reason to have the tiles wear down at a fast rate. Ideally The tiles should
> be the same hardness as the glass (there's another possibility for the
> tiles)
>> 
>> 2. That glaze? It's glass. Excellent stuff to have  rolling around on your
> mirror.
>> 
>> 3. What exactly is the composition of that glazed tile? Are there any
> inclusions in it? What is the hardness of the inclusions?
>> 
>> Even in porcelain, I recommend basic white. It's a higher quality,
> material and you don't have to worry about if the speckles are of a
> different hardness.
>> 
>> 
>> 
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