Paragon Kiln - SB-25 Sand Bath (Knife Making Kiln)

Sand bath heat treating is renowned for even temperatures. The sand fills a stainless steel crucible, which is held vertically inside the furnace. The crucible extends past the top of the furnace through a hole in the lid.

Please note: The crucible is not included with the SB-25. It is sold separately. The price depends on the diameter of the crucible. See the drop down choices to determine your final price.

Three thermocouples for precise heat measurement

The SB-25 sand bath kiln has three temperature sensors (thermocouples). Two are inside the firing chamber, and the third is immersed in the crucible through the top. The immersion thermocouple is sheathed for long life. It is held by an adjustable mounting bracket. You can raise the thermocouple out of the crucible by loosening and raising the bracket. When necessary, turn the bracket to move the thermocouple out of the way.

Air or inert gas makes the sand flow

A small amount of air or inert gas is pumped through the crucible from the bottom. This causes the red-hot sand to flow almost like a liquid, though the sand remains solid. A stainless steel sand catchment funnel at the top of the kiln (not shown in photos) prevents particles from bubbling out of the crucible.

The inert gas prevents scaling on the steel. If your steel doesn’t require the inert gas, you can pump air through the sand.

Heavily insulated; heavy-duty construction

The firebrick walls are 4 1/2” thick, and the top and bottom are 3” thick. The furnace includes a lid that fits on top of the crucible. In addition, the crucible extends out of the furnace through a hole in the main lid. The lid covered with stainless steel for protection from the hot sand.

Enjoy the convenience of a stand with locking casters. Gain access to switch box electrical parts through the easy-access control panel.

The furnace sections, wrapped in durable stainless steel, are held together with locking clamps.

TIP: The Product Managers, Developers, and Engineers, at Paragon, had the following recommendations for getting the SB-25 setup. 

You will need a tank of inert gas that is equipped with a regulator and a needle valve to adjust the flow of inert gas being introduced into the crucible.  Many users find that around 1-<2 PSI is sufficient to keep the sand bed moving.  You will most likely need a little bit higher pressure to get the sand movement started, but once you have it going you can then dial back on the gas flow to around 1-<2 PSI to keep the sand moving.  This is their recommendation, but you might prefer a more turbulent fluidic bed.  

The type of grit used is also important, and many users have the best results with 80 grit silicon carbide sand. Finer grits do not seem to work as well.

**Required safety equipment**

Please note that safety glasses are not adequate. It is essential that you wear a full-face safety shield, heat-resistant gloves, heat-resistant jacket, heat-resistant shoes, and heat-resistant pants. The sand is hot enough to cause severe burns if it spills out of the kiln.