BS: Lap Grinders

Subject: BS: Lap Grinders
From: Donuel
Date: 26 Jan 08 - 09:42 PM

Naturally when I went googling for lapidary equipment I ran into the national association of lap grinders and stripers.
Be that as it may

Does anyone have advice for a novice stone grinder.

I jumped in with 2 feet when I tried my hand at some luthier and new varnishing skills and within 2 years one of my violins found its way to a museum, so I have confidence that my eye for detail will help in my new endeavor.

I have some valuable boulders of opal from Koroit that I will eventually attempt to cut after gaining some skills on some lesser American opal slabs.

Mudcat haveing a wealth of craftswomen and men I thought it would be wise to ask you about dangers and rewards.

Don H

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 26 Jan 08 - 09:48 PM

btw I have a 8 inch grinder with diamond pads and a diamond trim saw as well as a big tile saw. Grandma was a rock hound so I am not entirely new to polishing.

Subject: RE: BS: Lap Grinders
From: Rapparee
Date: 26 Jan 08 - 10:42 PM

Opal needs sealing after it's polished or it will crack as the trapped water dries out.

The polishing depends upon what you're going to do with it.

Subject: RE: BS: Lap Grinders
From: Sorcha
Date: 26 Jan 08 - 11:32 PM

So, how big are these 'boulders'?

Out here in Wyoming, it better be higher than your head or it's not a boulder, just a rock.

If it's smaller than your head, it's a little pebble. (grin.....)

Subject: RE: BS: Lap Grinders
From: mack/misophist
Date: 27 Jan 08 - 11:20 AM

Check to see if there's a Gem and Mineral Society or the equivalent in your area. The local one has a work shop, classes, and experienced people around to offer advice. Except for purely technical matters, it's better to see some things than to read them. Above all, don't mix the grits on your pads. And start with something besides Australian type opal. It's considered difficult.

Subject: RE: BS: Lap Grinders
From: Tweed
Date: 27 Jan 08 - 12:22 PM

Nevermind...I thought sure this was regarding something you paid twenty bucks for in a Gentleman's Club. Lap Grinder sounds a lot grittier than table dance though, you may have inadvertently come up with a new category Donuel.

If this devolves into pun-laden nonsense, I want to apologise in advance.

Tweed

Subject: RE: BS: Lap Grinders
From: Rapparee
Date: 27 Jan 08 - 12:44 PM

Ya know, Tweed, that's what I thought at first too.

Subject: RE: BS: Lap Grinders
From: McGrath of Harlow
Date: 27 Jan 08 - 12:53 PM

Me too. It says something about us, I suppose.

Subject: RE: BS: Lap Grinders
From: wysiwyg
Date: 27 Jan 08 - 02:40 PM

Nope. It says something about the pervasively erotic media.

~S~

Subject: RE: BS: Lap Grinders
From: Tweed
Date: 27 Jan 08 - 02:48 PM

Thank god Susan! I thought I was having erotic thoughts of my own! ;~)

Subject: RE: BS: Lap Grinders
From: Mrrzy
Date: 27 Jan 08 - 07:02 PM

Hmmm - am I the only one who thought he dropped his hoagie on his pants?

Subject: RE: BS: Lap Grinders
From: Sorcha
Date: 27 Jan 08 - 07:25 PM

LOL, Mrz...probably. I was thinking along Tweed Lines...
and I still don't know how big this 'boulder' of opal is......
It's my birthstone, and I'd like to put a bid in for a hunk of it! LOL again.

Subject: RE: BS: Lap Grinders
From: Bee-dubya-ell
Date: 27 Jan 08 - 07:41 PM

I thought it was about someone who dropped a foot-long sandwich in his lap.

Subject: RE: BS: Lap Grinders
From: topical tom
Date: 28 Jan 08 - 09:57 AM

At first glance a very erotic, suggestive thread title but,alas, it turned into something about getting the dullness off one's rocks.

Subject: RE: BS: Lap Grinders
From: Amos
Date: 28 Jan 08 - 10:13 AM

IT's about people who often look like they are carrying a small hoagie in their pants, BeeDub. But who are actually just glad to see ya.


A

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 28 Jan 08 - 10:38 AM

Sorcha, some weigh a lb and some are just shards.

Birthstone eh, what is your favorite color? I can whip up an adjustable opal ring in 3 minutes flat.


http://img.auctiva.com/imgdata/6/3/5/3/5/2/webimg/99954439_o.jpg

http://i20.ebayimg.com/02/i/000/d3/ee/1966_3.JPG

this one has the thermal vent in which they form around still intact.
http://i20.ebayimg.com/01/i/000/d3/df/c160_3.JPG


http://img.auctiva.com/imgdata/6/3/5/3/5/2/webimg/99407442_o.jpg


wow
http://img.auctiva.com/imgdata/6/3/5/3/5/2/webimg/99965946_o.jpg


Last night one rough Koroit rock went for $300 but the cut gem from it would have readily fetched $1,000. Right now good "boulders" are going for 20 to 60 dollars. small bean gems called Cabs are plentiful but I only want to create large 3 inch broach sized dislays.

While the DARK semi translucent sparkling color gems go for 5 or six figures I feel that the painted rock in which Koroit opal is dispersed makes a far more interesting display.
Harlaquin is one term applied to some of the multicolor stones.

of course after polishing, Koroit black opals look even more intriging but even if a piece has scant few opals the designs in the rock matrix is my favorite. I have 3 rich wood colored slabs that are virtually all matrix but the accidental landscape or faces they form are more valuable to me than digging out a fleck of violet blue opal.
In fact if an opal does not create a noticable portrait or emotional image, I resell them in a heart beat.

Koroit is in Oz, The other Aussie hot spots are Queensland and (Coober Peddy?). Oh crap I just dropped my submarine sandwich...

Now I have to buy some diamond paste in various grit.
Good advioce, don't mix your grits,

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 28 Jan 08 - 10:58 AM

My 11 year old said "Dad that rock looks like moldy bread".

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 28 Jan 08 - 11:00 AM

ewww
http://i6.ebayimg.com/06/i/000/d3/eb/fffd_12.JPG

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 28 Jan 08 - 11:05 AM

Bag o' pebbles $179 pebbles

Subject: RE: BS: Lap Grinders
From: Rapparee
Date: 28 Jan 08 - 04:36 PM

You want unpolished opals, hell, I'll just pop up to Spencer on a nice weekend and buy 'em for ten bucks a pound pre-dug up.

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 28 Jan 08 - 06:09 PM

If it ever is on your way I will gladly pay for your time fuel and trouble to send me what you can carry.
I'll buy all the red and blue ya got. Most rocks at Spencer are probably yellow pink or peachish orange. Clear with flashing color can be a valuable find though.
Here in DC's Smithsonian, a average ten lb Washington St opal buolder costs $200 or more.

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 29 Jan 08 - 07:01 PM

Oh dear I have an ethical delemma.

David Freelander is a maestro jewler who specializes in opals.
Last week I saw his man made white opals.

I sorta tinkered around this morning and made some man made black opals. I start with highly polished but low quality opals with little bright colors.

My delemma is whether I should ever put these on the market represented as enhanced opals. While they look like enormously expensive opals they are not. The special materials I have to make them will only make about 50 black opals and I don't know where to get more color changing 1/2 micron thick diffraction flakes.

When a fake looks as good or better than the real thing its just one more fake thing in the world. On the other hand they are more rare than the real thing.

Subject: RE: BS: Lap Grinders
From: Sorcha
Date: 29 Jan 08 - 09:00 PM

Don, I've 'been told' that in fact MOST of the so called black opals on the market really aren't. They are a flake of cheaper opal laminated to a black substance (don't know what)

If you marketed them as enhanced, or man made, I can't see that it would hurt anything, esp. if the price were reasonable. After all, enhanced and or man made 'nearly any gem' is now available. My own engagement ring, a ruby, is a man made stone rather than Nature Made.

My problem is that I adore opals and don't wear any jewlery at all. It gets in my way, and generally just 'bugs me' when I have it on. What else can you do with an opal? Set it in the window and look at it? Well, ya...I actually DO have window sills full of Damn Rocks, as my family calls them. I even have a largish (4" or so) chunk of mica stuck up ON a window. I have Damn Rocks packed away too. Gods only know what my family will do with them when I die.

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 30 Jan 08 - 05:33 PM

Hmm no ring huh?
You could adorn a hat, a belt buckle, your shoes, your toenails, buttons, lapel pin...

ah oh I sound like Bubba listing shrimp recipes from Forest Gump.

Subject: RE: BS: Lap Grinders
From: Donuel
Date: 30 Jan 08 - 05:34 PM

I did not know most black opals are fake. I know some clear types cheat by have black foil underneath.

Subject: RE: BS: Lap Grinders
From: Slag
Date: 30 Jan 08 - 09:15 PM

If it were an organ grinder you needed then I guess the post would have gone, uh, above the line?