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Re: Lapidary thread

PostPosted: 03 Mar 2014, 21:56
by HBS Guy
Niters Lefty.

Re: Lapidary thread

PostPosted: 05 Mar 2014, 04:58
by Lefty
Faaark! Spent another 2 hours trying to grind that thing to the right shape. Still wasn't exactly what I wanted but I figured if I didn't stop I'd still be going next week and would have reduced the stone to a grain of sand. Tried to dop it with epoxy - didn't work, glue was too runny. Might have another go this morning with the wax instead.

Re: Lapidary thread

PostPosted: 05 Mar 2014, 19:49
by Lefty
Successfully dopped with the wax early this morning. Seemed quite easy in fact. Got home this arvo, stone nice and solid and the dop - good! Began cutting the pavillion for the square "Hapcut", a very simple cut with only 17 facets including the girdle. Felt the need to start with the 260 grit and then move to the 600. That's done now, gonna give it a rest for tonight. Tomorrow night will be the 3000 pre-polish and Friday night I'll do the 50 000 final polish before removing from the dop on Saturday and inverting to do the crown.

Re: Lapidary thread

PostPosted: 05 Mar 2014, 19:56
by HBS Guy
You will be a whizz soon!

Re: Lapidary thread

PostPosted: 05 Mar 2014, 20:22
by Lefty
HBS Guy wrote:You will be a whizz soon!


To tell the truth, it doesn't look quite like the picture in the cookbook :bgrin I see now that the pavillion facets aren't supposed to be all the same size - there should be four broad triangles and four very long and narrow ones. But hey, I'm having fun while learning :jump

Re: Lapidary thread

PostPosted: 05 Mar 2014, 20:36
by HBS Guy
The first one don’t even give to the wife. Tenth one don’t even try to sell :jump

Re: Lapidary thread

PostPosted: 05 Mar 2014, 20:57
by HBS Guy
The amethyst your Dad gave me is with a jeweller who will make a brooch from it—Mum’s christmass and birthday present.

Re: Lapidary thread

PostPosted: 05 Mar 2014, 20:59
by Lefty
Nice! A lovely stone is amethyst, especially the really rich purple hues :purple

No way, my first one is mine to keep - to remind of the things you're not supposed to do :bgrin I have already learned that you need to make the preform as square or as round as possible, you won't be able to cut away any lopsidedness. Also that coarse cutting laps can put tiny yet visible chips on the edges of stones. I'll get there in the end :jump

Night JM :zzzz

Re: Lapidary thread

PostPosted: 05 Mar 2014, 21:02
by HBS Guy
Niters Lefty. Amethyst is Mum’s birthstone.

Re: Lapidary thread

PostPosted: 06 Mar 2014, 20:21
by Lefty
Whew! Been trying to pre-polish with the 3000 diamond. It just wouldn't do it at first. I worked out that I was a bit heavy-handed and backed off a bit, whereby the result improved a lot. Still seemed to be struggling to make any noticable impact of the end third of the facet. Theorised that the tip of the stone is naturally riding up with the centrifugal force and might not be making firm contact - applied gentle pressure on the back of the stone so it was not possible for it to lift and the facet then polished all the way to the end.

No more tonight - am now relaxing with a :beer

Re: Lapidary thread

PostPosted: 06 Mar 2014, 20:45
by HBS Guy
hahahah I just bet you are!

But you are learning!

Re: Lapidary thread

PostPosted: 07 Mar 2014, 18:39
by Lefty
Finished the pre-polishing. Started one facet on the final 50 000 polish. It's not finished yet but it's knock-your-eye-out shiny reflective. :purple

It's the weekend tomorrow, will leave the final pavillion polish and re-dopping in preparation for the crown till tomorrow. Besides, this Sierra Nevada is telling me that it's time to give away trying to do anything that requires extreme visual focus and extremely steady motor co-ordination :bgrin

Re: Lapidary thread

PostPosted: 07 Mar 2014, 19:29
by HBS Guy
I drank one of the tins of Guinness I bought today—hey, had to be sure it was OK!

:bgrin

Re: Lapidary thread

PostPosted: 07 Mar 2014, 20:12
by Lefty
Ah, the good old cooks privellage - sometimes I have to adjust my recipes slightly in order to take *sampling* into account :bgrin

Re: Lapidary thread

PostPosted: 07 Mar 2014, 20:21
by HBS Guy
Pie will be awesome! So will the chips!

Re: Lapidary thread

PostPosted: 07 Mar 2014, 20:43
by Lefty
Good old Aussie pie and chips likely decended from Irish fare I would say :jump

Just discovered that it seems to polish better if the lap is turning anti-clockwise. Also discovered that you can have too much lubricant (water) on the lap - the distances involved are so tiny that too much water seems to allow the stone to 'float" on the lap surface, taking longer to achieve any result because firm contact isn't being made.

Boy, there's sure an art to it even with the precision-built machine with numbered dials to allow the kind of precise cutting that simply wasn't possible a hundred years ago.

Re: Lapidary thread

PostPosted: 07 Mar 2014, 20:52
by HBS Guy
Good to cut your teeth on this old machine before lashing out on a new one.

For once it is me saying it—niters Lefty.

That mincer looks great, reckon will do OK with it. Now I will have to try making sausages sometime soon :bgrin

Re: Lapidary thread

PostPosted: 07 Mar 2014, 21:10
by Lefty
Sausage-making is great fun! Endless flavour combos - be doing it right now if I had a sausage maker, it's agony on your back without one. Flavours that have worked well for me are char sui pork, garlic-oregano-thyme-sage-smoked paprika and dry red, chicken sausage with honey and roasted macadamia nut. Try em!!!


Night JM.

Re: Lapidary thread

PostPosted: 08 Mar 2014, 06:31
by HBS Guy
Oh I will! Was thinking of the vast array of sausages I could make, including fermented meat sausages (salami) and sausages to smoke (hot and cold smoking.)

Re: Lapidary thread

PostPosted: 08 Mar 2014, 18:54
by Lefty
Pavillion finished! Not professional but shiny and sparkly. But no transfer jig to re-dop :sad Not sure what the next step is now. Asking for advice from lapidary forum.

In the meantime, this Baileys is going down well :beer

Re: Lapidary thread

PostPosted: 12 Mar 2014, 19:45
by Lefty
Two Guninesses last night and by 8:00 I was :zzzz

No beer tonight, just coffee - might even last till 9:30 :yellow

Got a busted-arse old quartz crystal and put it on the same 600 diamond grit lap I was using for that other stone - it cut into it like a hot knife through butter. Went on to the 3000 and then the 50 000 final polish and in no time at all I had a nice, brilliantly reflective facet. A few people on the lapidary forum had suggested that I was having so much trouble cutting that stone because maybe the laps were heavily worn. I've just proved that isn't the case, it's just that whatever the stone is it's fucking hard! Almost as hard as the Glenalva damper :bgrin

Re: Lapidary thread

PostPosted: 12 Mar 2014, 19:50
by HBS Guy
That infamous Glenalva damper!

But—you have been grinding a very hard stone! Emerald, sapphire, diamond?

Re: Lapidary thread

PostPosted: 12 Mar 2014, 20:07
by Lefty
Hope to fuck it's not a diamond because if it is, I've reduced a million dollar stone to a few hundred thousand dollar one :jump

I strongly suspect topaz - fucking hard: check. Strong cleavage plane: check.

Got a piccie of the half-finished stone but I don't know if it really shows much, can't get right close up.

Re: Lapidary thread

PostPosted: 12 Mar 2014, 20:13
by HBS Guy
Yeah, can’t remember offhand to 1966 re topaz. Think the stone is harder than topaz tho—just a feeling.

Re: Lapidary thread

PostPosted: 12 Mar 2014, 20:19
by Lefty
Topaz is 8 on Moh's hardness scale, one down from sapphire which itself is one down from diamond (though it's not a linear scale). Been told that topaz can be tough to work with for a beginner and quartz - or even old broken tv screen glass! - is easier to learn on.