Chipper Sharpening

[Joe Pelonio]

I have a Troy-Bilt 10HP chipper-shredded and just bought new blades for the chipper, that I'll install next weekend. My question is, can the old ones be sharpened? If so, can I do it on my bench grinder? It appears to be merely a pair of blocks that have one edge ground onto them. At $49/$79 pair replacement it would be nice if I could sharpen and get at least one more use out of them.

[David Weaver]

I would build a slotted holder and hone them at a slightly steeper bevel on coarse sharpening stones or something like that, maybe even a belt sander.

What are they made of? Assuming that if you take a hundredth or so off of the edges that you can still adjust them tight on the chipper.

If you have calipers, you can make sure that the front edge stays parallel to the back edge.

Might take an hour to do the two of them.

[Joe Pelonio]

They are made of A8 Steel. That means nothing to me, I hope you know what it is. If it's going to take 1/2 hour each I may consider looking for a place that I can send them too or just look for a better price on new, but I will have to try it once.

It seems to me that the way they work, additional material loss from sharpening on that one beveled edge wouldn't affect the mounting. If I had to take down the front surface it could affect mounting if the countersink is shallow. (won't know until I take it apart and see the old ones up close)

[Joe Chritz]

A8 is a medium alloy tool steel that is shock resistant and fairly tough. It is generally used for just this sort of application. Many other steels are better for knives but for chipper blades it is very good. It is rarely hardened over 55 Rc so you can sharpen it like any other cutting tool.

They really don't need a hair splitting edge, just get all the knicks out and sharp to the touch.

I would use a course whetstone or sandpaper on a plate.

Joe

[Joe Pelonio]

Thanks. I'll definitely give it a try and have them ready when the new set gets dull.

[Dennis Peacock]

Put them on a Tormek and put an edge on them. I've sharpened stuff like this on mine and it's easy. I sharpened 2 pairs of "pinking shears" just yesterday on my Tormek.

[Jason Roehl]

Joe, I've got a 20 year old, 5HP Craftsman chipper-shredder that got handed up from my sister to my folks, then down to me a couple years ago. One of the first things I did was take it apart and sharpen the blades. I had them pretty sharp by the looks of the first few branches I put through it (clean crosscuts), but I put some drier stuff through that was probably pushing the size limit, and now they're not as sharp. I think I just free-handed them on a bench grinder with a white friable wheel.

Mine does pretty well with green branches up to about the size of my thumb, and I've found that it's much, much quicker to just throw all the little twigs in the shredder part with the leaves. That blade just looks like a small lawnmower blade. I also took the metal gate off the output so that it doesn't clog as easily. The chips/shreds are larger as a result, but it's much, much faster overall.

[Joe Pelonio]

Interesting stuff, Jason. Mine will do chip a 3" branch, have only tried green though, and since I bought it used was not surprised that the blades went dull after only a few hours work. Started to smoke a bit
ans slow way down, pulled the branch back out and found it charred

I agree that when possible the shredded is really easy to use, mine takes up to 1/2" so cuttings from pruning fruit trees are quickly shredded.

[Jim Becker]

Supposedly, the cutters on my Woods chipper/shredder can be sharpened...and they are about due, IMHO. I have a funny feeling it's not going to be a fun job, however, to take them off to get them to the grinder... :o