Lapping Compound for Hedge Trimmers

Discussion in 'Lawn Mowing' started by All_Toro_4ME, Jun 18, 2009.

  1. All_Toro_4ME

    All_Toro_4ME LawnSite Bronze Member
    Posts: 1,578

    My hedger is dull and just shreds when I cut shrubs with it. I've seen some guys on here use a dremel tool, grinder, etc to sharpen them with. I don't really want to go that route if I don't have to because I just dont think I could get the correct angle. The dealer here wont sharpen them, said its not cost effective to do so. New blades are hella expensive for it. Has anyone tried the lapping compound (same substance used to sharpen reel mowers) to sharpen hedge trimmers with? Would this work or is it too harsh and abrasive? Idea was to coat hedger blade in lapping compound and run the machine for a short period of time. Thanks.
     
  2. ALC-GregH

    ALC-GregH LawnSite Fanatic
    from PA
    Posts: 7,053

    I wouldn't try it. All that will do is eat up the smooth flat surface the blades slide on. You need to grind an edge on the cutting teeth. What you'll end up doing is dull them more. Take the time to do it right and quit being lazy. :D
     
  3. cgaengineer

    cgaengineer LawnSite Fanatic
    Posts: 15,782

    The lapping compound was my idea/suggestion ALC, I have never tried it and have no idea if it would work. All_Toro called me last nice and this was one of his questions so I told him to post a thread on LS for advice. My other suggestion was to sand the flat side of the blade on a piece of glass with some 80-100-120 grit sand paper. This would leave factory angle intact and remove very little of the blade surface.

    A quick call to Stihl USA informed me that you either use a file, 4" grinder (what he actually suggested) or the machine they sell to do it which is about $600.

    He said the hand file would keep angles better than the 4" grinder, but he said if you take it to a dealer they will use a 4" angle grinder.

    I have never used a hedge trimmer enough to dull them.
     
    Last edited: Jun 18, 2009
  4. kaferhaus

    kaferhaus LawnSite Bronze Member
    Posts: 1,444

    Lapping the bottom side of the blade works just fine but takes too much time.

    We use a die grinder with a cone shaped stone
     
  5. cgaengineer

    cgaengineer LawnSite Fanatic
    Posts: 15,782

    I figured it would work, but wondering if a fine compound would achieve the same result as sanding on a sheet of glass. My guess is it would be very dependent on the tension/torque of the bolts that allow the blades to slide and probably would not work well.
     
  6. kaferhaus

    kaferhaus LawnSite Bronze Member
    Posts: 1,444

    Actually we used a granite slab (old counter top) which is dead flat along it's entire length (about 6ft) and used 220 grit and then 400 grit wet/dry sandpaper stuck to the granite (water sticks it just fine) and then hot glued a couple of short dowels to the top side of the blade and used them as handles to slide it back and forth. Took 30 minutes or so and the blade stayed sharp for months... but just took too long. With the grinder you don't even have to take the blade off once you get the slots lined up properly.

    The whole job start to finish takes about 10 minutes.
     
  7. cgaengineer

    cgaengineer LawnSite Fanatic
    Posts: 15,782

    The granite slab is a great idea!
     
  8. All_Toro_4ME

    All_Toro_4ME LawnSite Bronze Member
    Posts: 1,578

    Thx for clarifying cga....
     

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