RWA3006
Cave Dweller 
Member since March 2009
Posts: 4,640 
|
Post by RWA3006 on May 10, 2021 21:08:48 GMT -5
I was digging through some blades I bought in an estate sale and found a 14" sintered blade that had been bent. I noticed it still had a lot of life left in the diamond matrix and wondered how hard it would be to peen it back out straight. Has anyone tried it?
I used to have a 52" circle blade saw mill and it was common to peen big blades back to true, but that's a different cat than a small thin lapidary blade. Somebody enlighten me please.
|
|
|
|
Post by hummingbirdstones2 on May 11, 2021 8:55:56 GMT -5
Can be done if the bend isn't too severe and if the core isn't stretched so much it oil-cans. Dead blow hammers are a good thing to have.
|
|
billdean
starting to spend too much on rocks
Member since April 2020
Posts: 153
|
Post by billdean on May 11, 2021 9:51:52 GMT -5
Hey Randy.........I don't know if this video will help you or not but here it is.
|
|
|
|
Post by Rockoonz on May 11, 2021 10:21:13 GMT -5
Key to the video is it's a non tensioned core. Old notched rim blades with the diamond crimped in are similar, but most sintered blades are tensioned and harder to straighten. The blade that's in my 10" slab saw, a real cabinet, not a trim/slab, is old stock and I straightened it after bending it when the belt broke and the feed kept running. It's cutting relatively good, but I'm only cutting really small stuff and putting larger stuff in the 14 with an unmolested blade.
|
|
Tommy
Administrator 
Member since January 2013
Posts: 12,989
|
Post by Tommy on May 11, 2021 11:03:36 GMT -5
RWA3006 it's hard to tell exactly what you mean by "bent" but if it's just dish shaped it should be repairable. I dished my 18" MK blade but have managed to bring it back from the edge of replacement by laying a 1" x 6" (ish) circular object centered under it and slowly pushing down and manipulating the blade just past the point of flat. It took a bit of persuading but it did come back to about as flat as I could get it with no heat and no hammering and it's cutting beautifully again.
|
|
RWA3006
Cave Dweller
Member since March 2009
Posts: 4,640
|
Post by RWA3006 on May 11, 2021 12:31:28 GMT -5
Thanks for the comments everyone. It's not dished, but had a pronounced dent in it that I imagine happened when a rock popped out of the vise.
I think I'll put it in a jack press and then peen it using techniques I used on massive saw mill blades years ago. I used to use 48 and 52 inch blades that ran a 3/8 kerf and I suspect some of the methods will apply to this challenge.
|
|
|
|
Post by Rockoonz on May 11, 2021 13:30:35 GMT -5
This is a technique for straightening a dished blade referenced from an old book called Gemcraft.  That is re-tensioning. You are slightly stretching the steel at the rim of the blade to slightly increase the diameter and stretch the center flat like a drum head. Like spokes on a bicycle, if not done correctly you can end up with a lot of wobble. |
|
