Solar powered glass tumbler...

Paul had a thread about better things to do with glass than recycling it.
As a result of that,  I found a YouTube video of a guy who had filled his garden beds with homemade tumbled glass.
He used a concrete mixer.
He advised against tumbling thin pieces,  as you ended up with "sand" and "dust".
I see a market for tumbled glass, sand and dust.
My family loves crafting,  and they are mighty charming, so we are considering setting table at the farmers markets around here.
I suspect that it's pretty cheap to run an electric cement mixer, but making the tumbled glass with solar seems cool,  good marketing,  and potentially even cheaper.
Mostly it seems cool.

The thing that makes this a good choice for  solar powered production is the incremental nature of it.
If the battery runs out or the sun goes down, the batch isn't ruined.
A half tumbled rock or peice of glass can wait forever to be finished.
The accumulated work remains,  the materials will not spoil,  and a tumbler  doesn't need anyone to watch it.


The small harbor freight concrete mixer needs 2.7 amps.
A 400 continuous 800 peak inverter should work.
Solar panels are about a dollar a watt, retail.
I will need a charge controller and a a battery bank at well.

This is starting to sound expensive for an unproven market.
Maybe I'm working things from the wrong direction.
I could start by building a DIY tumbler that is powered by a universal  motor.
That way I could try it out on mains power and if the glass sells,  I could invest in solar power.
By using a universal motor,  I wouldn't need an inverter, thus saving money and reducing losses.

Other things that could be produced by solar tumbling include  polished stones and seashells, compost and vinegar.
I wonder what would be the best thing to tumble bones with, if I wanted to make bone meal?
Of course,  polished bone would be another crafting item.
One last product idea: toilet grog.
OK, so grog,  the clay additive is made from, well,  clay,  that has been fired at high temperatures and then finely ground.
Ceramic toilets are made of clay,  fired at high temperatures.
Plenty of free,  broken toilets around...

What a cool idea! I'm keeping that one in the back of my brain...
I have a small rock tumbler that pulls a lot less power, wonder what it would do on solar?

My only thought here when pricing things out is that IN GENERAL gear from Harbor Freight is light-duty, limited-duty-cycle, limited-life-span stuff. Great for cheaply getting into and through one project; less great for long-term reliability.

If you are hoping to use the mixer/tumbler in continuous duty for weeks and months, it might be smart to price a contrsctor-grade unit into your thinking.

The abrasive power of black walnut shells would be a watt saving polishing medium.

...I prefer walnut now because it does not get stuck in the flash holes as much. Lately I've been adding a cap full of Nu-Finish car polish to it, every 5 or so runs, and half a dryer sheet. The Nu-Finish makes the brass shine more and the dryer sheet absorbs dust. link

I compost black walnuts between layers of soil in 5 gallon buckets (better keep a lid on them because if the squirrels can get to them they will) and by Christmas the hulls are less staining and easy to remove.

I like your idea.  I bought an old mixer for a dollar one day.  It is extremely heavy duty and is serviceable.  I  have been using an old junk ac motor to run it, but I just was given a 1/2 hp 12v dc motor to convert it to dc.  We use it to mix feed.  Its much easier than mixing in buckets.  I have been pondering hooking it to a pedal bike so it doesn't need electric at all.

At one point I considered doing this on a large scale with my seasonal waterfall. Very cheap to set up, I just didn't have faith that I'd find a market for the glass. You can buy big rubber tumbling containers the size of an oil drum.

I'll bet charcoal would work pretty well as an abrasive for the final polish. You get smooth glass and biochar broken down to a powder.

The best tumbler on the cheap idea I've come up with is to take an old dryer which is available for free, disconnect all of the heating and air blowing stuff and just use it as a tumbler. Insert an appropriate size rubber tumbling container and stuff the rest of the space with rags. It's already a tumbler and it won't draw much electricity when only used for that. Old dryers with bad elements are free. The cloth stuffing would muffle most noise.

I like Dale's tumble dryer machine idea, as it is ready-made, and cheap or free.
I can see thin glass getting broken down too far to be useful in a concrete mixer. I'd be tempted to remove or reduce the size of the paddles. For mixing concrete, you want the separating, lifting, and dropping to accomplish good mixing; but for tumbling it is unnecessary, you just need the parts to slide past each other.

The amount you fill the container is also important to get the right action to do the work efficiently. Look into "mass finishing", or "part deburring" for some ideas on how industry is tumbling small metal parts.

I'd also try it using ALL glass (no grit/polishing media) and maybe water? maybe a spot of soap? and see if that works. That way the fine glass pieces aren't lost in the media... Who knows if they might be a useful product in their own right, you'd be able to screen out the various sizes...

This should only be done wet.

My much-better-half is a glassblower, and an engraver. She uses a filter mask when taking the rotary tool with the diamond bit to the glass because she does it dry, and the "dust" you're creating has an abrasive effect on everything, your lungs included. It is a direct cause of silicosis. I have no desire for lung lesions due to silica, and I don't wish them upon my friends, or even my enemies.

-CK

Burl,  composting black  walnuts into an easy open state might make them worth messing with for me, what a great idea!

The dryer tumbler was my first impulse, it has been done before.
I figure after the drum is modified, the inside of the tumbler would be maybe 15 gallons.
That, my greediness for a cement mixer got me off track.
I have a spare dryer to play with,  but it still works,  so I'll save it for a solar heated dryer project.

A 55 gallon drum with an tire of larger diameter affixed to one end is my current ideal.
Mount the barrel in a frame, supported by casters ,and drive the tire via a pully from a universal(DC) motor.

Running the tumbler wet makes all kinds of sense.
I wonder, is the glass dust safe after it dries?
Probably not.
Mixing it with soil might sequester it.
I think I would prefer to keep it wet and use it in cement projects.

Growing up a family friend built a tumbler that ran in an irrigation ditch.  It was a fairly large tire with paddles screwed to outside.(racing slick)  They were made out of the angle between the tread and the sidewall cut like pieces of angle iron and screwed thru the flat leaving a slightly curved paddle sticking up.  It had a couple of pieces of tire screwed to the inside cause a tumbling motion rather than just sliding.(without them the rocks just slide around the inside.) One bead was screwed to plywood circle and the plywood circle was mounted to a shaft with some wood blocking  Pillow bearing blocks were nailed to some fence posts on either side of the ditch.  The open side of the tire had a sliding plywood circle on the shaft.  When the water, abrasive and and rocks were loaded the sliding circle was moved over to its bead and screwed in place.  The ditch had a couple of scrapes of plywood driven into the banks to keep the water from eroding around it.