Carving Obsidian - My "Saw"

[trapperjohn]

Here is a pic of my current "saw" setup:



I acquired the plans for this from YouTube's A. Ferreria.  For my application I have encountered the following issues:

1.  The depth of cut is too shallow.  This is a function of blade diameter and hub size.

2.  The kerf is too wide.  The diamond blade is an off-the-shelf contractor's blade with a .08 kerf.  Way too thick, but remember I am working with a common material and material waste is currently not an issue.
 
3.  The grinder's rpms are too high.  At 11,000 rpm chipping may become a problem.  The speed is also fixed.

4.  I need to build a rock vise.  I used my drill press vice to get this far but if you notice there is room to the left side of the stand, where at least one pre-drilled hole can be seen, for this feature. 

     Remember that my primary goal is to cut a working slab.  All blade related issues may be solved with a larger diameter, thinner blade - such as a proper lapidary blade.  The guide is easily replaced but the rpm issue still may constrain me in the end.  

The obvious solution to these challenges is to acquire a proper slab saw, or even a good tile saw.  I also must determine how often I will be needing to cut a good slab. Given the relatively high cost of the former and mixed opinions on the latter I need to determine what degree of commitment I'm willing to make before I fling money at the problem.  Thanks to several forum members I may soon have a lead on getting a used slab saw.  For the record I am not adverse to building my own unit, but I have zero skills at metal working so the design will need to be relatively simple.  
   

[Rockindad]

Love my angle grinders and there have not been too many days in the past thirty years where I haven't used one but this just is not what they are made to do, for all of the reasons you have listed. No used saws out your way? Nothing really to be had out here by me as the lapidary arts are not that big in this area, but I would think there would be a lot more out by you? Not sure what size material your are looking to handle but a cheap 7" tile saw can be had for the price of your grinder and a nicer one for not too much more- better all the way around and will keep the dust down.

Al

[trapperjohn]

Yep, a used saw would be nice. Guess I'll 'll keep my eyes opn!

[rockjunquie]

For years, I used a cheap skilsaw for under 100 and a good porcelain blade by dewalt. You could step up later if you wanted to, but this will suffice. I now have 4 small saws ranging from the thinnest imaginable slice and 4" saw up to the 7" inch skillsaw with a wider blade. (One of the saws was intended for my son, but it's still mine.)

[trapperjohn]

RJ, you not it right on the head. It's all about safety first, and then it becomes a question of trade-offs.

I plan on trying to "slab" a working piece of obsidian and continuing to play with it. I have learned a lot from the many posts here and once again thank everyone for their tolerance and good advice! I'll be sure to post progress as it occurs.

[parfive]

rockjunquie said:

For years, I used a cheap skilsaw for under 100 and a good porcelain blade by dewalt. You could step up later if you wanted to, but this will suffice. I now have 4 small saws ranging from the thinnest imaginable slice and 4" saw up to the 7" inch skillsaw with a wider blade.

A skilsaw, eh?   Upside-down?

Where’d ya pick up that trick, Bikerrandy’s house?     : )

[rockjunquie]

Jul 24, 2019 12:11:01 GMT -5 parfive said:

rockjunquie said:

For years, I used a cheap skilsaw for under 100 and a good porcelain blade by dewalt. You could step up later if you wanted to, but this will suffice. I now have 4 small saws ranging from the thinnest imaginable slice and 4" saw up to the 7" inch skillsaw with a wider blade.

A skilsaw, eh?   Upside-down?

Where’d ya pick up that trick, Bikerrandy’s house?     : )

YUP! he showed me how to do it.

[rockjunquie]

Jul 24, 2019 12:06:59 GMT -5 trapperjohn said:

RJ, you not it right on the head. It's all about safety first, and then it becomes a question of trade-offs.

I plan on trying to "slab" a working piece of obsidian and continuing to play with it. I have learned a lot from the many posts here and once again thank everyone for their tolerance and good advice! I'll be sure to post progress as it occurs.

I assure you- it is perfectly safe.

[pauls]

I think a tile saw would get you closer to what you are trying to achieve. Still not a slab saw but it is possible to slab small stones if you are careful and steady.

When the original tile blade wears out, put a lapidary blade on it. Have a way of feeding water down through the splash guard onto the blade, using it like a tile saw with the sump full of water you will get soaked.

I like your build, just not you are attempting to do with it.

[rockjunquie]

You can turn the tile saw around and work with the blade in front of you- "backwards". That keeps you from taking a shower. I had a picture somewhere, but now I can't find it.

[trapperjohn]

Pauls, you are correct in your conclusions. I think the real point of my attempts is to learn as much as I can with respect to my own interests and capabilities. My interest in carving is driving my stone cutting needs. Each day I learn more about what works and what doesn't . . . And what to avoid in the first place. Quite simply, if I can't carve, my interest in the many other aspects of lapidary is pretty limited at present.

It is interesting to approach this task as an unschooled novice. I read like crazy but it is through interaction with folks far more experienced than myself that I am learning. I wish there were clubs close by that would let me come up this learning curve more directly. This is not the case, so I rely on feedback such as that provided by you, Rockjunquie, and many others. Your feedback and opinions are much appreciated!

Later I'll post pics of my work thus far. I am sure many will look at it and shrug, wondering what all the fuss is about. After all, a proper setup would virtually guarantee results more quickly and of better consistency and quality to boot. Some of the work by experienced obsidian carvers is absolutely incredible, and I don't think I'll come close to achieving that any time soon. Assuming my carving skills develop, my comfort level in buying decent equipment will develop as well. I am also oPen to building my own gear. I just haven't put it all together yet

[rockjunquie]

I hear what you're saying. We all come at this differently.

I was reading an article last night about gemcarving. That's some serious art and skill. It's a natural spin off from where you are starting. Not saying that carving, in general, is an easy thing- I can't do it.

Just do yourself a favor and don't throw away your scraps. You never know....     (had to say it)

[trapperjohn]

Rockjunquie, I always keep my scraps, as I produce far more of these than I do "finished" work. That, and buckets of rock dust and wood dust.

I thought I had a "slab" that I could work with, but it cracked as I was sanding it. I think I pushed my tools and skills to the limit. I have definitely benefited from the experience and advice obtained to this point. But, cutting slabs as I have proceeded may be a bit like trying to learn how to ice skate without skates.

That's where sources like YouTube can be deceptive. While many people proudly show off their diy projects we never see how many failed attempts preceded the final product. I've stepped back from carving a howling wolf to a less ambitious product. I will also work on the details of carving a replica ammonite. Even though soapstone may be seen as a beginner's material, that's what I am in reality.

Another aspect of making diy tools is that tolerance build-up may ultimately do you in. Yes, my angle grinder with a diamond contractor's blade will in fact cut rocks. But my shop-built stand is +/-, and so is an angle grinder. A sixteenth of an inch here, a thirty-second there - it all adds up. Although wood carving is also a subtractive process and offers lots of opportunity for operator error, the processing risks are different. Not necessarily less, just different. But compounding the problems of getting a straight cut with sloppy tolerances on relatively harder material is a whole new ball game.

So, I will look into acquiring precut slabs and focusing on learning to carve them. Until I solve my equipment issues I think I'll work with "Beginner's rock" and properly cut slabs.

[jasperfanatic]

There's also the aspect of placing a value on the most precious resource any of us have - time. Unless engineering your own solution is part of the juice for you, you'll likely spend way more in the currency of time trying to create something or refurbish an old tool than just purchasing the correct or new tool to start with, time that could instead apply to the actual tasks of the hobby your most interested in. Even if someone is well into retirement, time is extremely valuable, maybe even more so at that point. As with anything, there are circumstances or exceptions, but I witness daily someone proverbially stepping over a dollar to pick up a dime...something I'm guilty of on occasion as well.

[pauls]

I have had a go at just about everything to do with Lapidary, I'm just not artistic enough for carving. Kudos to you though for giving it a go.
I love homemade tools and equipment, all part of the fun and learning curve.
Rock carving should be a lot safer than wood carving, less likelihood of losing a finger with a diamond blade, though dust is still a serious hazard.
You could try mounting a small diamond grinding wheel (cheapy angle grinder diamond blade) on the end of an arbor, run it at about motor speed so it's not the fearful speed of an angle grinder, rig up a water drip system and start work.

[trapperjohn]

Yep gang, I may have bitten off more than I can chew - at least with my present equipment. Jasperfanatic, you are so right about time. I have built quite a few jigs and fixtures and some of them actually improved life. My old buddy Tolerance Build-up may help account for this. And while a lot can be said for the practical learning that occurs with diy as well as the potential for savings, time is important.

I suppose I'm getting off track, for which I apologize. When you are thirty-something you may have more time than money. When you are older the reverse is often true. That's what trade-offs are all about! Mean time I'll work on softer material that is easily slabbed until I decide what to do. The howling wolf and the ammonite, for that matter, will be carved in soapstone, but the lessons learned will stay with me. I'll start a new thread to describe that work and let those interested know when I next attempt "hard" rocks.