sifu
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Member since September 2010
Posts: 35
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Post by sifu on Apr 9, 2020 15:17:38 GMT -5
My fascination is intarsia - not jewelry, but art pieces like those made by Meredith Jones, Walt Heinz, Joe Phettaplace, and Olive Colhour in the 1960s. I spent a day at the research branch of my city library photographing every article I could find in old volumes of the Lapidary Journal to build myself a resource manual on how to create intarsia. And there used to be a really cool website called Masters of Stonework that showcased all the great intarsia, but that has sadly disappeared from the internet for some reason. Here is my first piece. It's not 100% finished. I still need to square up the edges a tad and polish it.  I hope my image upload worked properly. Anyhoo - my goal is to gather some input on the best method for polishing pieces like this. Some are stained glass style, others will be mounted in frames, and I may do some game boards, etc. I won't usually want a mirror polish, more of a matte finish. The lapidarists listed above mostly built their own equipment, and it was usually some version of a flat lap, often quite large. In a few cases, they proceeded by polishing individual pieces of stone prior to gluing them into the larger piece. I have some reservations about going that route. It may work best for intarsia which incorporate stones of varying hardness, but for many projects it seems way too time-intensive. I've built my rock shop slowly over the past 5 years by focusing on creating a silica dust-free environment. I do NOT want to get silicosis or develop breathing problems, and my shop is in my basement, which shares some air with the rest of the house. So that's an important constraint: NO DRY GRINDING/POLISHING. Bull wheels are out. Working outside is not an option either. The other crucial constraint is the size of the pieces: I need to be able to get a uniform finish on pieces which may be a foot (or more) square. Whatever solution I use also has to work for polishing smaller things, like slabs, where I DO wish to get a mirror finish. Right now, I am considering one of the larger Rociprolaps. But is that really my best option? |
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Post by pauls on Apr 9, 2020 16:44:03 GMT -5
I have very little experience with intarsia, so thinking of this as a technical problem. A mirror polishing setup might be the way to go, so, your intarsia is mounted to a rotating table, overhead you need a buffing setup that reciprocates back and forwards as the work slowly turns under it. 1dave had a picture of the machine you want in a recent thread. This is too hard to explain without a lot of handwaving, goes off to look for 1daves thread. edit: there's a picture of the mirror polishing machine a fair way down in this thread. forum.rocktumblinghobby.com/thread/80669/facetieranother edit: here's a youtube of the sort of machine I am imagining. |
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sifu
starting to shine!
Member since September 2010
Posts: 35
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Post by sifu on Apr 10, 2020 20:38:12 GMT -5
Hmm. I wonder if such undercutting would also occur using a regular flat lap? I don't really want to build or buy a machine and then discover a huge problem like this in my process!
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Post by hummingbirdstones on Apr 10, 2020 21:01:14 GMT -5
mossyrockhound might be able to give you some tips on how he does his intarsias. I've tagged him so he'll see this thread hopefully. 
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mossyrockhound
fully equipped rock polisher
Member since January 2011
Posts: 1,315
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Post by mossyrockhound on Apr 19, 2020 17:59:37 GMT -5
mossyrockhound might be able to give you some tips on how he does his intarsias. I've tagged him so he'll see this thread hopefully. You're off to a great start! I like your pattern, selection of materials and end result. If I am doing composite cabs (which some refer to as intarsia) I just use my cabbing machine (Genie). For larger pieces up to 6" X 6", I build out from the center and finish on Expando drums. I haven't done anything as large as Meredith Jones's larger pieces, but he did show me how he finished them. He also had photos of his techniques in Lapidary Journal. Interestingly, 2 of the 4 people you mentioned (Meredith Jones and Olive Colhour) lived nearby here in Kitsap County, WA. We had another fine artist (Gene Maxwell) listed in "Masters of Stone" who lived nearby. I met Olive but didn't really know her - and I believe she was the most widely acclaimed for her wonderful work. I knew both men quite well. The 3 locals I mentioned each had their own unique style, which I am sure you too will also develop. |
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sifu
starting to shine!
Member since September 2010
Posts: 35
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Post by sifu on Apr 21, 2020 11:36:52 GMT -5
Thanks for the info. I think having great material inspires more locals to get into lapidary. Figuring it out is a process, for sure. I wish the American Masters of Stone website hadn't died - it was pretty inspiring. If I recall from the articles, Jones used a sort of large flat lap and finished his pieces whole - if that's correct, how did he prevent undercutting when using materials of different hardnesses? I need to come up to some Kitsap club meetings and pick people's brains. |
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mossyrockhound
fully equipped rock polisher
Member since January 2011
Posts: 1,315
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Post by mossyrockhound on Apr 22, 2020 20:04:02 GMT -5
Thanks for the info. I think having great material inspires more locals to get into lapidary. Figuring it out is a process, for sure. I wish the American Masters of Stone website hadn't died - it was pretty inspiring. If I recall from the articles, Jones used a sort of large flat lap and finished his pieces whole - if that's correct, how did he prevent undercutting when using materials of different hardnesses? I need to come up to some Kitsap club meetings and pick people's brains. You're correct about the method Meredith used to finish his large pieces. As near as I can recall he was pretty careful to use materials of similiar hardness, so undercutting didn't seem to be a problem for him. You're more than welcome to come up to our meetings (when they resume again). Send me an email before you come so we can compare notes when you get here. Also, please bring some of your work for show and tell. You aked about rociprolaps (vibrating lap?) in your original post. I forgot to mention that I have a lap wheel that I sometimes use to get saw marks out of my larger pieces before I start sanding, but I don't use 60/90 grit - it will "eat out" your joints in no time flat, ruining your piece. I start with 220 grit. I also have a vibrating lap, but I don't use it because it is too slow for my liking. It does a great job, but I just don't have enough patience for it. |
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berfle
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Member since April 2018
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Post by berfle on May 18, 2020 7:56:01 GMT -5
I too have been lamenting the loss of that wonderful American Masters Of Stone website. After poking around and searching a bit I found the below reference that seems to indicate that the content of the website may be available independently. I have a pending request into The Smithsonian but like everyone else, they’re moving slow these days. I’ll post an update if I receive a positive response. Some of you may have an association with one of the university libraries referenced and if so perhaps you may be able to obtain the info more readily. www.worldcat.org/title/american-masters-of-stone/oclc/46680006 |
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Post by hummingbirdstones on May 18, 2020 8:16:49 GMT -5
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berfle
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Member since April 2018
Posts: 42
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Post by berfle on May 18, 2020 8:35:05 GMT -5
A few thoughts on polishing Intarsia. My experience has been with smaller, jewelry sized pieces, probably 3” or less. If I’m creating a piece that is going to be polished absolutely flat, then flat lap finishing is required. In this case it’s important to work with stones of similar hardness because the entire piece is in contact with the lap at all times and small chunks of the harder material can and probably will, break off and scratch the softer material.
The vast majority of my work is finished on a multi-wheeled grinder (e.g. Genie, etc.). With this approach I’ve never had a serious issue with mixing stones of varying hardness. Also, with this approach you can choose to finish the piece with a high dome (e.g. composite cabochon style) or with such a low dome that it will appear to be flat. Most of my work is with harder stones but occasionally I’ll need to mix hardnesses (e.g. rhodonite adjacent to rhodochrosite, malachite next to bruno, etc). In these cases, I know ahead of time that if I’m aggressive on the wheel, then I run the risk of undercutting (cupping) the softer material. Therefore, I use a very light touch during polishing and realize ahead of time that it's probably going to take a little longer to complete. In reality, at a “magnifying glass level” there will still be some undercutting however, if done carefully, it will not be visible.
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berfle
starting to shine!
Member since April 2018
Posts: 42
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Post by berfle on May 18, 2020 8:42:51 GMT -5
hummingbirdstones Thanks👍 Wow, yet another item to add to the vast list of stuff I didn’t know anything about😁 I’ll poke around and see if I can recover the source files.
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berfle
starting to shine!
Member since April 2018
Posts: 42
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Post by berfle on May 24, 2020 17:48:53 GMT -5
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Post by hummingbirdstones on May 24, 2020 23:15:05 GMT -5
You're welcome!
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carver
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Member since November 2019
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Post by carver on Jul 12, 2020 21:19:36 GMT -5
was anyone able to recover this amazing website? I've tried the WayBack but most pictures are so low quality as they don't save the full picture size. Were you able to get the CD from the Smithsonian library? This website is exactly what I am interested in.
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