When to replace disc mower knives

[lacamo]

I'm real happy with my Kuhn GMD disc mower that I've used for 2 seasons. While getting it ready for this year, I noticed there are nicks on a couple of the knives, probably caused by the occasional stones, ledge, etc. At what point should I replace the knives? Is it practical to hand sharpen them? Should I replace them all at once or just the ones that are damaged?

Thanks.

 

[flusher]

I'm real happy with my Kuhn GMD disc mower that I've used for 2 seasons. While getting it ready for this year, I noticed there are nicks on a couple of the knives, probably caused by the occasional stones, ledge, etc. At what point should I replace the knives? Is it practical to hand sharpen them? Should I replace them all at once or just the ones that are damaged?

Thanks.

I don't own a disc mower, but, just off the top of my head, if I did, I'd buy a new set of knives. I'd worry about upsetting the balance of the mower heads by trying to sharpen old knives.

 

[sweettractors]

I'm real happy with my Kuhn GMD disc mower that I've used for 2 seasons. While getting it ready for this year, I noticed there are nicks on a couple of the knives, probably caused by the occasional stones, ledge, etc. At what point should I replace the knives? Is it practical to hand sharpen them? Should I replace them all at once or just the ones that are damaged?

Thanks.

Most users sharpen blades with a 4 inch angle grinder while on the machine. Have to hold the blades with vice-grips or something to keep them in one place. If they get rounded on the cutting corner, then they should be replaced. The Manufacturer recommends changing the blade bolts when you wear out a set of knives. Ken Sweet

 

[lacamo]

A box of replacement knives with bolts and associated parts came with the mower. Maybe I'll try grinding the old ones now and then do the replacement prior to second cutting to better mow the finer grass. Thanks.