Monday, August 11, 2014

Gonna need a bigger boat...I mean saw!

Picked up some nice rough rock on our last trip to Boise and managed to identify the source for some stuff that we have. We've also hit on a slight problem...

The stuff I want to cut is bigger than my saw blade... working on a couple solutions though. I've pretty much always had stuff bigger than I could cut at the moment, but this is stuff I want to cut right now! So the search is on for bigger saw solutions (yes I could try two passes over the blade but being able to cut it in one pass is better).

Let me show you why I'm all jazzed about this material....

This is a piece of the material I want to cut. This particular one is just about exactly the height of the saw blade. It's petrified wood from the area of Bruno, Idaho. As I understand it the material in this location was limbs that were broken off,washed down river, and then covered with volcanic ash. This scenario creates petrified wood that looks like regular good old drift wood...

right down to the grain pattern in the wood. But, trust me this stuff will destroy any normal wood saw you tried to put it on, it is a real rock. I have a couple projects in mind for this stuff I just have to get it worked down to proper slabs.  Some of it will just barely fit my saw in one pass and some of it is bigger... I have a piece of some different petrified wood we picked up that is definitely too big for this saw (and will probably top out the 10' saw I'm wanting to get). Unfortunately for that piece we'll need not just a new saw but a new 240 volt line to go with it! Those big lapidary saws are no joke power wise...

In the mean time I tested out a new tool this week, a mini disk sander. Not just any mini disk sander (lots of those), but a diamond system mini disk sander.

These little guys go in your Dremel/micro motor/flex shaft and are used to polish stone after it's been shaped the way you want it.  I am really pleased with it and I've learned a few things with it that I'll pass on (I'm also thinking of bringing it (and other related tools) with me to Cali next time we go (at the reunion more than one parent expressed an interest in us showing folks how to make stuff with the pretty rocks and not just collect them).

First, a good work surface is a must... you don't need a jewelers bench, but you will probably want a DIY bench pin or similar sacrificial surface to work on.

I use one of my home made ones for this and not my nice professional one because the professional one I have mounts in a steel bench block... This technique uses water (and sprays water!) and I really don't want to rust my bench block (allowing your metal working surfaces to get rust pitted is a capital offense in some shops!).

Second, this system uses pressure sensitive adhesives (PSA) on the pads. It also uses pressure and fairly high RPMs (2-10 thousand). This means that just putting the pad on with your fingers might not be enough pressure (by might I mean probably isn't). Like many other personal problems affixing the pads to the mandrel can be nicely solved with a few light taps of a hammer.

While we're at it remember  back in my post on making the workbench? Remember the Denim catch drawer?

This would be one of the situations where this item is really helpful. More than one pad slipped out before I got them affixed properly and more than one pretty stone has made the jump for life... the denim catch drawer (sling?) has faithfully intercepted them before they hit the ground. Hitting the ground tends to break or mar stones and other things just disappear. A little hand me down denim and a couple grommets and hooks saves head and heartaches.

Third, water and pressure are a must for the pads to polish right but not too much of either. To much water makes it harder for the pad to work and to much pressure tends to break or throw things (and throwing rocks is another machine's job!). You want firm but not crushing pressure and you want enough water to wet the pad and create a moist past over the stone (being more specific is hard, but you'll know it when you see it. 

With the notch in the pin this would be a good place/time to use a dop stick, but that is another post...

Here's a finished stone that I'm ready to put a bail on...

It's actually shinnier in person (enough so that the flash doesn't work well on it and my disperser was MIA...)

Well, that's it for today. Lisa will handle next weeks post and I'll be back here in two weeks. 

In the mean time if you need more insane ramblings check out my other blog at

No comments: