Category: Offtopic

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Offtopic Tutorials

Documenting a Success: Clearing SiC Yellowing Post Polish in a Glass Studio

Sometimes a tinkerer needs to accomplish something that literature says requires special lab equipment…

There is very little information online about correcting silicon carbide (SiC) discolouration outside of an industrial laboratory. After some experimentation in our glass studio, we successfully cleared the yellow tint from SiC using a modified atmospheric annealing process. Here is how we did it:

The Problem: Lattice Defects from Overheating during Polishing Turn White Moissanite Yellow

Yellowing in SiC is typically caused when clear or ‘white’ Moissanite gets too warm during faceting or polishing. I believe this was a 6H or 4H stone. To clear these, the material must be heated to a range where the atoms can “reset,” but doing this in open air causes the surface to oxidize and char.

The Custom Setup

We bypassed the need for an industrial vacuum furnace by repurposing high-heat glassblowing tools and cannabis paraphrenalia to create a controlled inert environment:

  • The Chamber: A high-purity quartz banger. Quartz was chosen for its ability to withstand extreme temperatures without cracking or reacting.
  • The Atmosphere: We flowed high-purity Argon through a flow meter into the bottom neck of the banger. We kept the flow very low—just enough to maintain a positive-pressure “blanket” that displaced all oxygen.
  • The Heat: An oxygen/propane glassblowing torch.

The Process

We took multiple tries at heating and cooling the stone. Three times of raising to glowing hot, briefly holding, and then cooling. There’s no way for us to know that those three heats were as good as one big heat – but this is simply what happened and worked in our little setup.

  1. Slow Warm-up: We brought the temperature up gradually to avoid thermal shock.
  2. Visual Heat Management: While we used a thermal camera and a thermocouple to monitor the start, our equipment maxed out at 1000°F. We pushed significantly hotter, using the bright incandescent glow of the crystal as our indicator that we had reached annealing temperatures.
  3. The Reducing Flame: To cool the piece, we used a large, bushy reducing flame. This provided a gentle thermal taper while adding an extra layer of protection against oxidation.
  4. Cycling: We repeated this heat-and-cool cycle three times.

The Result

By the end of the third cycle, the yellowing had completely dissipated. By maintaining a strict Argon environment and controlling the descent with a reducing flame, we achieved laboratory-grade clarity using studio equipment.

With precise atmospheric control and a good “feel” for heat, the yellowing of SiC can be fixed without industrial-scale machinery.

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Design Offtopic

MAD MAX: Fury Road – Art, The Dust Gun, and Preparations

While it may be old news, late is better than never. Prior to the release of the new Mad Max: Fury Road release, my sister – Elysse Melo – and I were tasked with transforming cars off the streets of Toronto into Mad Max inspired dusty works of art.

I designed and made the graphics for set decor, installing and accenting the set with custom crafted props.  The whole day would have been a flop had it not been for a few clever decisions in our planning stages.

The intent originally was to fill squirt bottles with vegetable oil, and lightly coat vehicles so that SFX dust could be sprinkled onto the vehicles. We settled on pressurized cans of canola oil cooking spray. Pre-filled and consistent, the cooking spray cans were ideal for fast and controlled application.

Sprinkling the dust was wasteful and left an uneven layer which was difficult to work with. Throwing the paper-dust at the oil-covered car worked better still, and so an idea was born.

Drawing from my knowledge and background working with air brushes, I designed and built a custom dust cannon. Our first prototype was a simple water bottle with a dip straw and air inlet in it’s side. Slow to fill, and easily jammed – it proved the concept, paving the way for version two.

The new dust cannon was not only a huge improvement in speed, but also efficiency as well. With a multi-valve setup and shop compressor – my tool was ready to make mini dust storms on queue. It looks pretty cool too.

Here’s the SFX dust cannon, made of ABS and copper:

Finished product.

To further speed the project along, I partnered with DWS Creative Imaging to craft a set of stencils and other tools to speed up the dust-painting process. With my direction, we were able to exceed all expectations – decoration far more cars than previously thought possible.

Categories
Offtopic Tutorials

Broken Digital Pocket Scale – Troubleshooting and Repair

This is an off-beat post, and has nothing to do with websites or the digital world for that matter. I’ll be going through the steps I used to fix a broken pocket scale that was gifted to me – I get a lot of, “If you can fix, it it’s yours” gifts.

This 50.00g digital scale stopped working for an unknown reason, and the top suggestion for fixing these scales is a re-calibration. Unfortunately, this digital scale could not be calibrated – likely a result of the problems it was already having. After further inspection I realized the scale still accurately measured negative values. At this point the, “if it’s broken and destined for the garbage, I had might as well see how it works.” Was running through the back of my head.

Check the video out for a quick little tutorial and walkthrough of how I got my scale back in mostly working order. Step-by-step below.

  1. Remove the top plate of your scale to gain access to the mounting points of the weight surface.
  2. In my case there were two Phillips screws
  3. Flip the scale and remove the battery cover to reveal the second mount point
  4. Remove that pair of screws and set them aside as well
  5. Under where the weigh platform was, flip the sensor bar
  6. Re-attach all components

The kicker is, now when I lift the weighing platform, it shows me a proper positive number – reversing the fix brings the problems back. Does anyone with more knowledge of digital circuitry have an explanation for this rogue resistor?