THinking about replacing my platens.

Shane Justice

Shane Justice

Active Member
Well I am thinking about taking the advice of a fellow knifemaker and replacing my platens with D2 hardened to 60-62 Rockwell.

Does anybody have thoughts or "one betters" for me.

I have been using the Use one side, flip it, re-flatten, begin again method.

Thanks!
 
I replaced mine with D-2 @ 62 RcC . I made a couple of them, drilled and tapped the backs so I could resurface them when they finally do wear. Haven't had to yet. I also changed the rollers on my Bader flat platen from alum. to D-2 @ 60 RcC . Ceramic sounds good but can it be ground. I do have a surface grinder that I have diamond wheels for. Never ground ceramic before . I have milled machinable ceramic for jobs at work but I doubt thats the same thing.
Anyone have any advise.
 
I have also heard of people using glass for the flat platen . I tried that but it kept shattering on me. I guess its some type of certain glass . Tempered,hi temp ??????????? dont really know but the glass is probably your cheapest way if you know the right type to get .
Anyone know??
 
Put it on with J B Weld and it will help cushion it. Ceramic is super slick so it doesn't drag like the steel will. Sure made a big difference in tapering tangs for me.
 
I agree with the ceramic. It cuts way down on heat build up, and once you grind on it, you won't want anything else. I've gone the whole gambit.....and nothing I've used works as well as the ceramic.
 
I've been using a piece of regular glazed bathroom tile for over a year now with no problems so far. I was using 6 inch tiles, so I cut a strip out of the middle of one that was exactly as wide as my 2 inch belts.
 
I thought about mentioning this before, but I have also used just regular 1/4" plate glass with great success. I have a local glass shop that cuts 4 pieces at a time for me (2- 6x2" and 2- 8x2") for less than $20. All I do is acraglass them to my 5/16" thick mild steel platens, bolt the platen back onto the attachment, and I'm grinding. Obviously regular plate glass isn't as durable as ceramic, but if your not too heavy handed they last for a long time. Plus, it's generally locally available, and works while I wait for an ordered piece of ceramic to arrive. (can't get the ceramic loccally in Montana)

Another tip: Sooner or later you will have to replace a platen liner. Some folks have a hard time removing the old glass/ceramic.....it's easy if you simply remove the platen from the attachment, lay it across the jaws of a vise, and heat the backside with a propane torch until the adhesive lets go. Cool off the platen, then surface grind it or bead blast it, and your ready to glue the new glass/ceramic in place. I also use an "eze-lap" course diamond sharpener to radius off the lead in and trial out edges of the glass/ceramic to prevent any sharp edge from grabbing a belt joint.
 
disclaimer - I sell ceramic platen glass so take the following for what it's worth:
I've used soft and hardened (O1 steel) platen and ceramic works the best I've used. The main drawback to ceramic is that it acts like a static charge generator. It will throw off a fairly healthy blue spark while grinding which can be troubling to some people. The size of the spark varies with the belt and speed of the grinder along with the humidity. The fix is easy, spray the inside of the belt and around the machine with Static Guard laundry spray.

There are several versions of high temperature glass. You can find fireplace glass locally nearly everywhere. Call your local glass store. 1/4" thick will work.
Get a price before you order it locally. Most glass stores will charge you a minimum and may include one cut for free but generally charge a cut fee too. Other trademarks include Pyrex(tm) and Corningware(tm). The main thing is this stuff takes heat quite a bit better than regular glass. It does wear but it will wear at a slower rate than steel.
 
Shane,
Listen to Boss an Ed.
Ed has his MS stamp that = Mentor Stamp to me and you:biggrin:
I didn’t listen you what Ed told someone else on the same subject because I already had the material and I just wanted to see for myself.
Well let me tell you what I did that I never will do again. I had some A8 steel a wet grinder and some time at work. I made 2 very nice looking platens 12”x2”x ½” with tapered ends and all. Went home put one on the grinder, slipped on a belt, set the tracking, grabbed a knife blank and started grinding. Oh man a good flat platen sure helps step up someone game-------------------for about 5 minutes.
Want to take a guess at what happens to ½” thick steel after about 5 minutes of grinding?

WARNING!! Don’t touch it you’ll leave your fingerprint.

And it holds the heat forever. Grind 5 minutes let cool for 30 minutes. Nope when it cools off enough down here again for me to get back to the knives then Boss will be getting another order from me:thumbup1:
 
I could not believe the difference when I switched from steel to ceramic. I don't believe I would ever run a steel platen again because ceramic runs so much cooler. As Tracy said sometimes you get some static but I only notice it here in the winter.
 
Yes even the glass will ware out and need replacing. I do all of my conture grinding with a flat platen. If I get to wondering if the glass is worn, I simply lay a straight edge across the glass. When you are grinding if there is a worn spot the belt will want to follow the surface change. It will make a definite unlikeable grinding change in your work, starting with a little and increasing as use goes on. Look for this problem and you may solve a big one. that may happen.
 
OK. Ceramic platen liner is the way I will go. ONe of the things that I did not pay attention to several years ago was checking all of my surfaces for straighness. AND the other thing I did not look at was which parts were crowned, and which ones needed to be.

As a new guy I spent a lot of time fighting the machine and then haivng mediocre results. I got into trouble a bunch of times, and was too far in to fix the problem.

On top of it all I am exceedingly left handed, which to me means my right handwas stronger than my left, since I used my left hand for fine motor skills and the right to do the muscle.

All of these little inconsistencies, quite frankly, kicked me in the pants.

I think what I will do is start with fresh flat, straight platens, and then attach the liners to them.

Thank you to everybody for all of the great input.

Believe me, when other guys speak, I listen. I dont think anybody comes here to spout non-sense. Everything I have read shows that the information is fact based, from experience and offered with the intention of promoting quality craftsmanship.

Thanks again!
 
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