SteveW
Elder Statesman
Posts: 1,395
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Post by SteveW on Jul 15, 2004 21:07:51 GMT
Guys,
I need a couple of 10mm holes in two pieces of 4mm glass and have a set for glass/tile drills up to 10mm. Do I start with a pilot hole and grow it to the final size or use the 10mm drill and use a one-pass approach?
I think I have the low down on using turps as a cutting fluid and intend using either a hand brace or slow battery drill (with lowest torque setting).
Another question: What is meant by 15 ounce glass? What is the nearest current equivalent size?
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Post by alanstepney on Jul 16, 2004 2:05:10 GMT
I have found the easiest way is to make a dam of plasticine or putty around the hole, or rather, where it is going to be, and fill that with turps or even paraffin.
That keeps a good supply and adds to cooling.
15 oz, was the weight per square foot. (if my memory os working, but might have been a different area but the same idea!)
That is VERY light. I doubt that you will find anything that thin except in a glazing specialists.
Normal window glass runs around the 28-32 oz. again, from memory.
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Post by Tel on Jul 16, 2004 10:45:59 GMT
I've never had much luck with those glass drills - find it easier to use the copper tube/valve paste method.
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PeteT
Active Member
Posts: 27 
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Post by PeteT on Jul 16, 2004 18:23:04 GMT
Reinforce last post, I have in the past (about 30 years ago) drilled many holes in thin glass to make small discs which were used in scientific instruments. Used a pillar drill with a bit of soft tube (brass or copper) and a bit of grinding paste. Moderate speed and VERY light pressure and plenty of paraffin to keep cool. Don't remember any failures.
PeteT
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SteveW
Elder Statesman
Posts: 1,395
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Post by SteveW on Jul 19, 2004 19:56:16 GMT
Replies noted, thanks.
Why do I want to know? I saw a a couple of Wimshurst machines at Harrowgate and feel its about time to get off the fence and start one. The current design stems from an old book I had as a kid, 'The Handy Boys' Book' although I'm not too sure what that is nowadays.
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Post by Roger Mason on Jul 20, 2004 8:46:36 GMT
Hi SteveW,
I believe I have seen Whimshurst machines made using the old fashioned (how times change) records as the disks. They already have the hole in the middle!
Tee Publishing reprinted an old booklet entitled "The Wimshurst Machine How to Make and Use It". The original booklet was by Alfred Marshall, and published in 1908, Tee's reprint was published in 1984, and might still be available from Tee or Camden.
In my view this booklet is a "must have" if you are contemplating making a Whimshurst. It contains plans and descriptions.
I hope this helps.
Cheers,
Roger Mason, in St. Agnes.
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