How to Install a Glass Platen for your 2x72 Grinder

Описание: Eiljah with Fire Creek Forge demonstrates how to install a glass surface on the steel plate or platen attachment of a 2x72 belt grinder. Elijah installs the ceramic glass on one of his KMG-TX platen attachments from Beaumont Metal Works to build his glass platen.

The flat platen attachment has a mild steel plate which provides a flat, solid, smooth grinding support. Over time, the steel plate will develop small depressions from repeated use. The Beaumont Metal Works steel platen plate is symmetric in all three axes. This means that it can be turned upside down to enable usage across its entire surface to control for use on abraded or worn sections. It also means the steel platen plate it can flipped over to use either the front or the back side. Additionally, new replacement steel platen plates can be purchased easily and inexpensively at BeaumontMetalWorks.com. Still, here are two reasons why a glass platen is preferable to a steel one for grinding, and Elijah demonstrate how to build a glass platen in this video.

0:27 First, a ceramic glass platen reduces the friction of the abrasive belt running across its flat surface. This means that flat grinding with a glass platen produces less heat than flat grinding against a steel platen. Less friction is less heat, which is especially useful when grinding a heat-treated knife blade or other metal and managing heat is important for maintaining the proper hardness and temper of the material.

0:50 Second, ceramic glass platens wear better than a piece of steel. Primarily because of the lower friction, the glass platen will retain its flatness for flat grinding much longer than a steel platen plate.

01:10 Glass platens for grinding must use high temperature glass aka ceramic glass, such as glass used in wood stoves or fireplaces. There is significant heat generated from the abrasive belt running across the ceramic glass platen.

1:43 Build the glass platen with these materials.

2:00 First, use industrial strength reinforced epoxy such as J-B Weld Cold Weld to hold the glass on the steel plate, and to provide structural support and complete void fill. J-B Weld Cold Weld two-part epoxy is steel reinforced and delivers a tensile strength of over 5000 PSI with temperature tolerance up to 500 degrees Fahrenheit when fully cured.

2:48 Second, use a coarse abrasive emory cloth to clean the steel platen plate as preparation for the epoxy.

2:55 Use ceramic glass which is sized to fit the steel platen plate. Here the ceramic glass is 2x8 inches, which covers the 2x8 steel platen plate. This piece of ceramic glass cost about thirty dollars.

3:25 A set of supporting pins or a small shelf can be created at the base of the steel plate to provide a secondary structure to keep the glass on the platen in case the epoxy fails or the glass cracks.

3:53 Clean the glass thoroughly with acetone.

4:01 Use a coarse emory cloth (J-weight) to clean the steel platen plate completely. Hand sanding with the coarse abrasive removes any rust or grime and delivers enough roughness to the steel surface to improve the adherence of the epoxy. Wipe all dust off with a clean rag.

4:48 Prepare the two part industrial strength epoxy (J-B Weld Cold Weld).

5:55 Apply the mixed epoxy evenly and completely over the steel plate of the flat platen.

6:18 Clean the ceramic glass with the acetone and let dry, then position over the epoxy and press in place. Apply pressure and movement to eliminate any air bubbles and ensure a complete bond between the ceramic glass and the steel platen plate.

7:57 Make sure the glass is properly level and aligned on the steel, and scrape off any excess epoxy. Clips are used to maintain light pressure and proper position the epoxy while it cures. A full cure will take about 24 hours.

8:28 Adjust the glass platen plate so that it is closely aligned and parallel to the outside of both idler wheels / pulley wheels of the platen assembly. Being too proud and extending more than 1/16 inch past the tangent of both idler wheels increases drag on the back of the abrasive belt, increases belt heat, and can even bog down some electric motors. A platen plate which is slightly recessed from the common tangent of the idler wheels will lead to inexact and undesired flat grinds in which the workpiece contacts the abrasive belt before reaching solid flat backing. A platen which is slightly “proud” to the idler wheels ensures that the abrasive belt maintains contact with the glass platen during use so that all flat grids are fully supported. The platen’s glass surface should be level between the idler wheels and extend no more than 1/32 – 1/16 inch past the common tangent of the idler wheels

Shop for professional quality 2x72 belt grinders such as the KMG-TX at BeaumontMetalWorks.com