In my October 2011 column, a reader had a question regarding a source for Natrium 60 for blasting. Although I could not determine the source, I assumed it had to do with sodium bicarbonate blasting for paint removal. I wrote a bit on that subject and asked the readers to contact me if they knew any more regarding that specific product. Tim Herman of Natrium Products responded with a good overview of sodium bicarbonate blasting. As it turns out, his company offers a product that was likely what the reader was looking for: Natrium 260.
Natrium Products supplies the blasting industry with three different grades of sodium bicarbonate based on size distribution. The three commercial grades it offers are the Natrium 150, Natrium 260 and Natrium 300, with the number representing the approximate median particle size in microns (actually the 150 has an average size of about 160 microns, the 260 about 290 microns and the 300 approximately 340 microns). As a point of reference, the particle size of the typical baking soda you may have in your refrigerator is in the range of 65-70 microns, less than half the size of the smallest industrial product Natrium offers.
Mr. Herman further explained the pros and cons of the different size grades. The smaller the particle size, generally the less expensive it is and the gentler in stripping. However, it can also have potential drawbacks related to dust generation due to the smaller size and difficulty viewing the work article because of the size and dust. The larger 260 and 300 products may be more economical in the long run if they generate less dust and allow the worker to be more productive, since he can see the work article and progress more readily. The larger particle size product may also work faster since it will have more momentum and greater stripping capability.
I want to thank Mr. Herman for his time in providing me the background and usage of his product. An article also appeared in the May 2010 issue of Process Cleaning focusing specifically on the subject of sodium bicarbonate blast cleaning (see processcleaning.com/