Flat lap grinder questions + Vari-etch ?

michey · Post by **michey** » Tue Apr 06, 2004 5:22 pm

In researching a small lap grinder, I find I have questions.....

My goal for the machine is to get better flat edges on my fused pieces and grinding flat sides to my lampwork beads. The first will be most likely be firepolished in the kiln, the latter ground to a shine manually. My work is small so doubtful more than 1/2" glass per side would ever be removed. My finishing skills are somewhat lacking so I am trying to remedy that. Any opinions of which machine will best meet my needs? I am leaning towards the magnetic one but no practical experience here.

I found this one company mentioned in the archives...... http://www.hisglassworks.com/pages/8grind.html and has a 8" grinder. The disks attach magnetically. I see minor mention of this in the archives but not enough to make a decision. Those of you that use this style, do you like it or not? If not, why? It 'sounds' great but I have no practical experience with these machines.

Others I am looking at: http://www.kingsleynorth.com/grindingunits.html scroll down to the Hi-Tech All-You-Need Diamond Lapidary Machine and http://www.arrowsprings.com/html/tools_part_2.html scroll down to the bottom of the page

Neither mention magnetic so I am presuming they don't. The KN photo even shows what looks like a long screw/bolt. How much time is involved in changing out disks?

I work small, I consider a coaster large and generally work under 3". Most of my work is of wearable size or miniature. Is the 8" considered an acceptable size for this? The obvious answer is yes but would like opinions from those with actual hands-on experience.

On the disks I have tentatively picked out, for the magnetic version, 80, 270, 325( smoothing pad), felt pad. Is this good grit choices or should it be changed? If so, what would be a better choice? The other two machines come with disks. Kinglsleynorth machine: Each machine includes #180 mesh metal bond diamond disc, #325, #600, #1200 mesh diamond smoothing disc, a tech 10 polish pad with 14,000 mesh diamond compound, 4 each disc backing plates and complete instructions. Arrow Springs machine: 100, 260 and 600 MESH DIAMOND PLATED GRINDING DISK , 325 MESH DIAMOND SMOOTHING DISK and felt pad. If I went with one of the latter two machines are the disks acceptable for my goals? I am also open to other options.

Next cerium oxide. In the "Warm Glass" book it mentions sometimes having to move to a finer grit of cerium oxide. At the companies I have looked at there has just not been specification of grit size. Do I need to know more about this? If so could someone either explain a bit or refer me to a reference that I can study?

And last questions, anyone use Vari-Etch Frosting Powder? Does it etch Bullseye glass consistently? If you have used it, do you like it?

Thank you for any help in this,
michey

charlie · Post by **charlie** » Tue Apr 06, 2004 5:28 pm

if you only do small stuff, you can get away with a 6" lap. it's not much cheaper but the disks are.

Marty · Post by **Marty** » Tue Apr 06, 2004 11:42 pm

You use cerium on the felt pad. (I'm not sure where cork comes in).

6" discs (with no center hole) will let you do close to 5" diam. work. A single machine with magnetic discs will work fine. Your grit choice sounds reasonable- experience will tell you if it's right for your work. I like 45 or 60, 120, 280, finish, felt/cerium when going further than sandblast.

Vari-etch is not consistent on BE. I find opals are more forgiving than transparents, and it seems to be more agressive on reds. It works best on sandblasted glass- gives it a tooth to work on. It's not the sliced bread I thought it would be, but it does have its uses.

BTW, HIS Glassworks has a short video on diamond pad grinding, and some pretty good info on etching with VE.

michey · Post by **michey** » Fri Apr 09, 2004 8:25 pm

Thanks for your help. I actually looked at the 6" but have learned from the years buy one size larger than I think I need.

I understood what the cerium is for and when. The part I didn't understand was the different grits. Guess I'll figure it out as I go.

Thanks again,
michey

jerry flanary · Post by **jerry flanary** » Fri Apr 09, 2004 11:34 pm

Something else to consider might be something like this http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... me=rvi:1:1 or http://www.hisglassworks.com/pages/b2.html

A lot of european beadworkers use wheels to grind facets. Also the edge of a "coaster" could be easily cleaned up on a wheel. HisGlass Also sells four station arbors so (if you can build your own tools) you could set up with Diamond wheels on that and then another station for cork and cerium. or take off a diamond wheel and slide on the felt wheel.

Cerium is a messy business. So it's nice to be able to keep it in it's own little area. Different Grits of Cerium? I guess it's possible but I can't remember ever worrying about it. That is a more common concern with Pumice. (Known back in the day as Rottenstone

) Pumice is a bit like curry in that it is a collection of "spices" and so each Pumice can be a little different if I understand it correctly.

Finish work is very much up to the individual. Each person finds what finish they like best. Some use cerium, some pumice, some horsehair. It's an area where you can relax and just see what you think works the best for you.

Get an MSDM on the Vari-etch before you order to make sure that you want it around your studio. I have heard that it does a wonderful job and I saw some pieces at the ACC in Feb that had a varietch finish that were really nice.

HisGlass has wonderful customer service so call bob up after you've done a little research and ask him some questions. He may have a better solution that none of us have thought of. (I am not affilliated w/ Bob)