Thread: Added a flat platen to home made grinder

finally got around to adding a flat platen for my grinder, thought ya'll would like to see some pics. Its 2" angle iron...some additional spacer plates of steel to get it to line up right.

Lynn was actually saying that adding a piece of glass to the platen surface would give me even better results -- I have no reason to doubt him... anyone else using glass on their flat platen?

I have "read" this...tempered of course...

I don't know anyone that has actually tried glass - the steel gets polished after several hours of work. My KMG has a lot thicker steel on the flat platten - don't know if that would be a factor or not. I just went the other way and got my 8inch wheel set up, so I can hollow grind the razor I'm working on. If it turns out half way decent, pictures to follow.

I'm really digging the versatility of this attachment....I'm not even sure if I'll need to change it, ever.. 4", 8", flat platen and slack belt all built into one piece.. mere seconds to switch from one to the other. Jamie @ polar bear forge really nailed it.

i could see myself getting a 10" contact wheel..some day!

My understanding about the tempered glass is that it doesn't build up heat like the steel does. I can't remember where I have the information stored, but if I recall, the key to the glass is what you use for adhesive. Some epoxies will not allow for the rapid expansion and contraction due to heat. Otherwise, as you mentioned, the glass is supposed to be superior to wear as well as heat.

I have pyro-ceramic glass on my flat platen. It's the kind of glass they use for glass doors in wood stoves, etc. I got mine from USA Knife Maker Supply. They have instructions for installing it on the page where they sell it. The glass gives a nice smooth surface, but it also seems to create problems with static electricity build up. Lots of people get zapped. I usually wear surgical type gloves when grinding, just to keep my hands from having grit imbedded in them. I haven't been zapped while wearing the gloves.

PS: Tracy Mickley (USA Knife Maker's) recommends gluing the glass on with JB Weld. I used double stick carpet tape, which seemed to be popular on BladeForums. However, I did attach a metal step" (a piece of stainless steel I screwed onto the metal platen) below the pyro-ceramic glass to keep it from sliding down. By all accounts, the step it the key to keeping the glass from slipping off and shattering.

From a purely theoretical standpoint; glass is a great insulator, so it shouldn't conduct the heat down and away from the belt. The surface may get hotter, but should cool quickly because only the surface will get hot. Metal, on the other hand, will draw the heat from the surface down and to the rest of itself, so it will stay hot as the whole thing will have to cool off. Same goes for spare electrons; they'll build up on the surface of the glass but will travel into the metal, and the grinder is probably either grounded or large enough to prevent a static shock. You may be able to figure out a way to successfully ground a glass plate, should that become an issue, or you could just periodically touch it to ground it yourself.

Or you can just use the metal. That's all I have ever done, and I don't see any problems with it. I really like your 2 wheel/flat platten set up, Undream. I have a rubber wheel at the top of my flat platten, so I can grind smaller raduses, and that works slick.
Have you had any vibration issues with that metal tube you are using to connect to the body of the grinder? I use solid metal bar stock, and it would seem heavier is better, or am I just over thinking the process?

Zero vibration issues. I could NOT find 1.5 x 1.5 solid steel bar anywhere.. this was all I could find. Originally I was worried, and assumed it would only be temporary until I found some solid, but, after a bit of use, you'd never know it was tubular / had holes in it

I'm debating now whether or not to build a tool rest...the grinder has another 1.5x1.5 mount for another tooling arm. I think I can get by without....but.. I dunno, its tempting

Ordered my kit from Mr. Boley today...with the multi platen upon some good advice.

My postmaster may not like me when they grab a hold of that box full of solid steel...