JACQUES LORD wrote:
> I am currently repolishing my F/6 6-inch and f/4.5 8-inch mirrors. I
> made
> them 19 years ago at college and never kept the tools. {:~( I found
> Newport
> Glass in the yellow pages some time ago and acquired the tools and
> grits they
> supply to begin regrinding. I have started the 6 inch a week prior to
> finding
> the ATM digest. The Newport tool with the channels is astounding. Is
> it my
> imagination, or do the additional edges of the channels make for a
> more
> efficient tool and less time between grit sizes? I had my 6 inch
> stripped by
> QSP (?) in Santa Ana. My 8-inch is still coated. Do I have to get it
>
> stripped, or can I wipe it out in a session or two of 180 grit?
>
> The postings in the digest and the archives have been a great help.
> Here is
> my summary of the most helpful bits of guidance I gleaned from my
> searches in
> hopes it helps future searchers. I am currently fine-grinding:
> 1. Two seconds per full cycle on the stroke rate.
> 2. Keep the surface wet - once I feel a tug I drip some more water on
> the
> working surfaces or wash up and start a new wet.
> 3. Be VERY mindful of cleanliness - some great hints and procedures
> for
> keeping the mirror and tool free from cross-contamination in the
> archives. I
> think I'll shave my head between grits....
> 4. Cover the mirror and tool after each session with a fresh sheet of
> plastic
> wrap - dispose of it - don't use a towel, paper or cloth, to
> "protect" your
> glass; they only harbour scratches-to-be.
> 5. The sharpie test is wonderful. A real confidence builder when all
> wears
> away evenly and pits are identified and slowly wear away. If that
> doesn't
> happen I know where to get help (here!).
> 6. Don't push too hard or go too fast while grinding - irregular
> surface will
> result (some interpretation here; I could be off base)
> 7. 2 hours per grit size. (This would seem to be diameter dependent?)
>
> 8. I am keeping a log/record of my grinding and observations - I read
> a good
> one in the archives by someone from New Jersey - the keeping of a
> journal
> keeps me mindful of lessons learned and how much (or little) grinding
> I have
> actually done.
>
> I hope I have got the above summary as accurate or at least not too
> distorted
> - but these got me going from worrying to grinding. I believe that
> NOT doing
> the above things 19 years ago gave my f/4.5 the irregular surface and
> 3/4-1
> wave error that it has (if I am reading Suiter correctly). On to the
> 5
> micron! (another good search topic in your archives!)
>
> Jacques Lord
-- BEGIN included message
- To: owner-atm@shore.net
- Subject: Removing scratches and pits from coated mirrors.
- From: "JACQUES LORD" <jacquesplord@msn.com>
- Date: Fri, 8 Aug 97 03:38:32 UT
I am currently repolishing my F/6 6-inch and f/4.5 8-inch mirrors. I made them 19 years ago at college and never kept the tools. {:~( I found Newport Glass in the yellow pages some time ago and acquired the tools and grits they supply to begin regrinding. I have started the 6 inch a week prior to finding the ATM digest. The Newport tool with the channels is astounding. Is it my imagination, or do the additional edges of the channels make for a more efficient tool and less time between grit sizes? I had my 6 inch stripped by QSP (?) in Santa Ana. My 8-inch is still coated. Do I have to get it stripped, or can I wipe it out in a session or two of 180 grit? The postings in the digest and the archives have been a great help. Here is my summary of the most helpful bits of guidance I gleaned from my searches in hopes it helps future searchers. I am currently fine-grinding: 1. Two seconds per full cycle on the stroke rate. 2. Keep the surface wet - once I feel a tug I drip some more water on the working surfaces or wash up and start a new wet. 3. Be VERY mindful of cleanliness - some great hints and procedures for keeping the mirror and tool free from cross-contamination in the archives. I think I'll shave my head between grits.... 4. Cover the mirror and tool after each session with a fresh sheet of plastic wrap - dispose of it - don't use a towel, paper or cloth, to "protect" your glass; they only harbour scratches-to-be. 5. The sharpie test is wonderful. A real confidence builder when all wears away evenly and pits are identified and slowly wear away. If that doesn't happen I know where to get help (here!). 6. Don't push too hard or go too fast while grinding - irregular surface will result (some interpretation here; I could be off base) 7. 2 hours per grit size. (This would seem to be diameter dependent?) 8. I am keeping a log/record of my grinding and observations - I read a good one in the archives by someone from New Jersey - the keeping of a journal keeps me mindful of lessons learned and how much (or little) grinding I have actually done. I hope I have got the above summary as accurate or at least not too distorted - but these got me going from worrying to grinding. I believe that NOT doing the above things 19 years ago gave my f/4.5 the irregular surface and 3/4-1 wave error that it has (if I am reading Suiter correctly). On to the 5 micron! (another good search topic in your archives!) Jacques Lord
-- END included message