Ceramic platen liner question

Barker

Barker

Joined
Dec 24, 2005
Messages
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I was just tapering the tang on a knife. I was using the new ceramic platen liner I just JB welded on Thurs. night. I notice after tapering the tang on this knife that the platen has a crack all the way across it about 5" down from the top of the platen. Am I screwed? I'm thinking I should replace it. Anyone have this happen to them, what did you do? Thanks.

-John
 
yep Happend to me. Bolt that holds my platen on went through and pushed the jb weld into it and cracked it but good. Stil used it for a while just cant use it in that spot. or it leaves lines/worms. Got it from ellis as well.
 
I have a full crack in the same spot. Luckily for me, I typically use the top 5" of the platen free hand and the bottom couple of inches for profiling/rough grinding. Just don't grind over the crack and you can live with it for a while.

--nathan
 
I've been using glass on my platen for a number of years, and have had a number of folks contact me with the same issue as you have. What I have found in most cases is that the metal platen material was not perfectly flat. A secondary cause that I've also seen is the adhesive having "bubbles" or "gaps" after setting.

The key to making a "glass" platen liner last is ensuring that the metal portion its attached to is perfectly flat (surface ground), and use an adhesive that is fairly thin in consistency. For me a surface ground 50-60 grit finish on the metal platen, and accra-glass have done the trick. The latest glass was applied over 3 years ago and is still in great shape.
 
Barker said:
I was just tapering the tang on a knife. I was using the new ceramic platen liner I just JB welded on Thurs. night. I notice after tapering the tang on this knife that the platen has a crack all the way across it about 5" down from the top of the platen. Am I screwed? I'm thinking I should replace it. Anyone have this happen to them, what did you do? Thanks.

-John
Click to expand...

mine did the same as all of the guys here.
i just blamed it on one of the guys that wanted a different belt on it and pulled on the platen to get it tight.
but i will have to pay for another one any way.
i'm still using it anyway.
vern
 
I believe my crack was likely the result of a bubble in the too thick epoxy I used to attach it like Ed suggested. Also, I wouldn't doubt that my cheapo Grizzly metal platen isn't dead-on flat.

--nathan
 
Just a another idea. On my NWG I used a piece of regular ceramic floor tile. All ready had it and a tile saw so I thought I'd give it a try. Lot of texture on the back of the floor tile so I used a heavy coat of JB weld to glue it up. used a pressure pad and as many spring clamps as I could fit on it. I have ran the heck out of this set up and it doesn't generate excessive heat.
 
I broke one by letting my tool rest slide into it while removing. Bruce pump just got a piece of D2 from me for a platen rebuilt. From now on I think I amd going to go with a piece of hard (400f temper0 polished D2. Should last a long time and never break. Jim
 
bikermikearchery said:
Just a another idea. On my NWG I used a piece of regular ceramic floor tile. All ready had it and a tile saw so I thought I'd give it a try. Lot of texture on the back of the floor tile so I used a heavy coat of JB weld to glue it up. used a pressure pad and as many spring clamps as I could fit on it. I have ran the heck out of this set up and it doesn't generate excessive heat.
Click to expand...

how long you have yours this way.
vern
 
+1 on the ceramic floor tile. I installed mine the same way as bikermike and mine has worked fine for over a year.
 
Just made a platen out of 3/8" X 2" X 8" precision ground O1. Need to heat treat next. Anyone else using this?

Eric
 
I've been tring to resist replying - but I have to. PLEASE replace it if it's cracked. Try to envision the result if it comes loose at full belt speed. BAD THING!:eek:
What Ed Caffrey said double.

  • If it broke, it was probably glued to a less than perfectly flat surface
  • Knife grinding is about finesse - not power. Ease up.
Rob!
 
I used to have it on my Burr King, but I've gone back to a super hard piece of D2.

I think the glass allows a little less friction, but it all wears down. People say the glass never wears, but I had grooves in mine. And it was the same stuff everybody else is using.

With the D2, I can slap it on the surface grinder, clean it up, and I'm good to go.

Jim, I might have to buy some D2 from you like Bruce did, I'm not sure if I have enough left to make a new platen for the new KMG. I better check!
 
No problem on the D2 Nick. I am thinking about making some up, I was just thinking it would be nice to have a regular and one with well rounded edges and set up my platen so I could change out the D2 faces easily.
 
NickWheeler said:
I used to have it on my Burr King, but I've gone back to a super hard piece of D2.

I think the glass allows a little less friction, but it all wears down. People say the glass never wears, but I had grooves in mine. And it was the same stuff everybody else is using.

With the D2, I can slap it on the surface grinder, clean it up, and I'm good to go.

Jim, I might have to buy some D2 from you like Bruce did, I'm not sure if I have enough left to make a new platen for the new KMG. I better check!
Click to expand...

I did one up for my KMG out of precision ground O1, harden it and never tempered it. Then I put some glass on it.:confused::confused: It's still there going on 6 years.
 
efleming said:
Just made a platen out of 3/8" X 2" X 8" precision ground O1. Need to heat treat next. Anyone else using this?

Eric
Click to expand...

Been using O1 for two years now, no grooves or scratches. No glue or potential fragmentation grenade either. When this one wears out I will use it as a template for the next one. I like the saftey margin of four 1/4-20 countersunk machine screws over JB weld. Plus there won't be any glue residue to deal with.

I have also noticed that with a non-insulated metal platen the static electricity bleeds away so I never have any sparking issues.
 
B Finnigan said:
Been using O1 for two years now, no grooves or scratches. No glue or potential fragmentation grenade either. When this one wears out I will use it as a template for the next one. I like the saftey margin of four 1/4-20 countersunk machine screws over JB weld. Plus there won't be any glue residue to deal with.

I have also noticed that with a non-insulated metal platen the static electricity bleeds away so I never have any sparking issues.
Click to expand...

Great to hear. Thanks!
 
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