Here is a great video and article on glass bead sandblasting.
This company is using a fine glass bead to remove bronze patina from outdoor monuments, which restores them to their original state. I would have liked to see some before and after photos of the monuments, but the article does contain a video clip where you can see (from a distance) the cleaned and uncleaned areas.
Workers from Sterling-based Mercer Lettering and Monument Works have been sandblasting and pressure-washing the granite stonework over the past few weeks. The granite stones also have been treated with an organic acid designed to preserve the grass below while removing fungi from cracks in the stone.
On Thursday, they aimed nozzles at the bronze plaques and sprayed them with fine glass particles. That removes the patina, or green and brown film, that has developed on the metalwork over time without damaging the metal below it, said Graeme Everson, the company’s owner and a National Guard veteran.
“It brings back the shine of the bronze as it was when they put it up,” he said.
The article does not discuss the size of the glass bead used, nor the exact machine they used, but the video shows the actual operator blasting. You can therefore see the blast pot and the operator’s protective head gear which is useful for those just starting out and not familiar with protective gear.
To see the full original article by By ALISON SHEA of The Bulletin: Jewett City monuments gleam like new – Norwich, CT – The Bulletin http://www.norwichbulletin.com/news/x1474279320/Jewett-City-monuments-gleam-like-new#ixzz21poiW0in
© Copyright (c) ALISON SHEA The Bulletin Originally Posted May 18, 2012