All About Abrasives Usage in a Trophy and Engraving Shop.

This article talks about abrasives. What type of abrasive to use, how often you should change it, when to clean the filter and how important it is to keep your abrasive dry and foreign particle free.

Types of abrasive to use

For Sandcarvers in trophy and engraving shops we recommend using aluminium oxide 150 grit. You could use different grits for different jobs such as a finer grit for halftone images but changing the abrasive is a task and time consuming.150 grit tends to work fine for all typical jobs in the trophy/engraving business.

150 grit allows very fine line etching and give a good bright textured and frosted finish to glass. The finer the grit, such as 180 or 200 grit the smoother and whiter the etching looks. The courser the grit such as 120 or 100 grit the courser the etching looks and can have a rougher looking finish. Courser grits will also be harsher on PhotoMask stencils although SR3000 etched properly can withstand 100 grit. We find that 150 grit works perfectly well as for a good bright finish and very fine detail even with half tone.

When to change your abrasive.

Aluminium Oxide comes in 25kg bags. You can fit the full bag into our Rayzist pressure pots but we suggest you just put half a bag in. It is really fast and clean to re-fill the Rayzist pots with the auto re-fill feature and by only using half the bag you have some reserve abrasive that has not been used.

When you blast the abrasive loses a tiny bit of its structure and slowly becomes rounded and smaller as particles break off on impact. Eventually the abrasive does not cut the surface as fast so production slows down. I remember a time when I was blasting A4 panels of glass with clear text and sandblasted background. It was taking around 10 minutes to blast each piece. I decided to change the abrasive over to a new batch and the blasting time came down to just 2 minutes. Using fresh abrasive makes a big difference. So keep an eye on your abrasive. Some people have a label on the pot with the date you put new abrasive into the pot so they can keep track of how old the abrasive is.

As a guide to when to change:

  • Small shop use blasting once or twice a week: 1 bag per year
  • Medium shop blasting around 8-10 hours per week: 1 bag every 6 months
  • Blasting 20 hours per week: 1 Bag every 3 months
  • Blasting all day everyday: 1 bage per month

Keep the filter clean

The Rayzist Pressure Pots have absolutely fantastic dust filter systems that keep the viewing area clear of excess dust whilst dragging out the broken abrasive and glass particles from the spent abrasive ensuring the reclaim is good clean cutting abrasive. Maintaining a great filter system requires simple maintenance on a regular basis. Use the shaker at the top of the cabinet to rattle of settled dust from the Teflon filter bags. Do this every day after use and you will keep you filter system in great shape and in turn your abrasive as good as it can be. See also: Sandblasting Machine Maintenance

Keep your Abrasive Dry

Abrasive sits in a metal pot and needs to be dry to stay effective. Moist abrasive sticks together causing coagulation so abrasive flow becomes hampered leading to blockages or sporadic abrasive flow. If your workshop is in a very humid area moisture can form in the pot or in the compressor leading to damp air.

Firstly make sure you empty the compressor tank each day to expel any moisture build up. It does help to have a moisture filter in the airline between the compressor and the pressure pot to trap any moisture in the air. In regards to the pressure pot release the pressure when not in use so that the pot lid is open and fresh air can get in.

Keep foreign objects out of your pot.

Whenever you add abrasive to a pot it should be dry and have a sifting tool to catch any lumps or foreign objects so they don’t end up in the pot and your blasting system. The Rayzist Systems have a built in sifting mesh so when you add or recycle the abrasive is always sifted. If you have a different type of blaster and there is no built in system we have a sifting ring available or you can use some fly screen mesh as a sifter.

Whilst many of us like hanging out at pubs and bars cockroaches tend to love the pressure pot environment. When your pressure pot is open they love the dirty warm environment of an open pressure pot.  Once sealed and pressurised the cockroach turns into a blocker and can cause blockages in blast lines. This is not an issue for the Rayzist and ABRA systems as the pressure pots are built in and clsed the the bug public even when un-pressurised. if you have a sandblaster that has a pot exposed when open cover the inlet with a towel or cotton cloth to keep foreign object out.