Sharpening Blades

Discussion in 'Lawn Mowing' started by Expert Lawns, Aug 8, 2002.

  1. Expert Lawns

    Expert Lawns LawnSite Silver Member
    Messages: 2,660

    all i have is a bench grinder. i don't think i'm sharpenin them the right way. they dull fast and are inconsistant. how do you guys sharpen your blades and whats the best way to use the bench grinder. maybe i'm taking too much off or going at a bad angle
  2. nova385

    nova385 LawnSite Member
    from Mid MI
    Messages: 69

    I remove them and use a hand file. I keep 4 sets (2 gators + 2 highlift). I'll pull 'em off and jam on the other set. Sharpen the dull ones I pulled off when I fell like it.
  3. Cut 2 Please

    Cut 2 Please LawnSite Member
    Messages: 221

    You really need a dedicated blade sharpener. I use a friends RBG now but I am saving to buy a Magna Matic. You will find that many people here love the Magna Matic. There are several problems with using a bench grinder. 1) Many times you do not get the proper angle on the blade. 2) I always seemed to get hot spots on the cutting surface which weakens the blade and lets it dull faster. 3) Unless you are really good your cutting surface will have a wave pattern. 4) The blade will tend to be unbalanced.
    I use to sharpen blades on a bench grinder and had the same problem as you. I then started using a disk grinder with the blade being held in a vise. This worked better. However when I discoverd the RBG blade sharpener I realized how blades are supose to be sharpened. If the Magna Matic is so much better than the RBG like I have read in many posts I have to have one. Do a search and you will find a wealth of info. Also Magn Matic is an advertiser on this site and there is a link to their web-site.
  4. Doc Pete

    Doc Pete LawnSite Gold Member
    Messages: 3,469

    I don't seem to have a problem using my grinder. You'll get better results with at least an 8" diameter 1" wide wheel. I adjust the grinder base plate, where I rest the back of the blade on, so that the back of the blade is in the middle, when the face of the blade is at the correct angle for sharpening. I sharpen my blade at about a 30 degree angle, which more, or longer than at 45 degrees. You also need the "extremely" rough grit number, which is lower than the "rough grit" of #46.
    All I do is hold the end of the blade with one hand and position the other hand as close to the end I intend to sharpen, without bumping into the grinder, as you slide the blade back and forth. Besides needing a welding glove for the hand close to the end your are sharpening, I use "aluminum tape" wrapped around my thumb, otherwise the amount of red hot metal coming off the blade with burn a hole through the thumb part of the glove. It takes me about 5 minutes to sharpen and balance one blade, 15 minutes for 3.
  5. awm

    awm LawnSite Gold Member
    Messages: 3,354

    this will work tho theres better ways that cost more money.
    1 take time on the edge and never allow the metal to heat up. this happens and the steel edge breaks like glass.
    2 use more angle than is normal .
    this will allow more support to the edge and will hold edge better for me.
    3 just knock off any burrs on the bottum of the edge. dont sharpen from that side.
    again take plenty of time so it does not build heat.
    like i said theres better ,more modern ways . but this works pretty good for me .
    i forgot, did i mention dont allow any heat to build up . any blue or black edge aint gonna stay past the first yd.
    good luck to u.
  6. Expert Lawns

    Expert Lawns LawnSite Silver Member
    Messages: 2,660

    thanks for the tips guys. wow, that mega matic sharpener costs a pretty penny.

    now, why does heat play such a big role?
  7. Cut 2 Please

    Cut 2 Please LawnSite Member
    Messages: 221

    The heat weakens the metal and makes it more brittle.
  8. Expert Lawns

    Expert Lawns LawnSite Silver Member
    Messages: 2,660

    so when the blade gets weak, it doesn't stay sharp as long?
  9. gogetter

    gogetter Banned
    Messages: 3,256

    Expert, I know when I first found LS and saw guys talking about these $500-$900 blade grinders, I was like "no way I'm spending that kind of money for a simple blade sharpener!, That's crazy!".

    Now I can't wait to get one! I was taking 8-10 blades a week to a sharpening guy and paying $5 per blade. THis was running me $40-50 a week. I'm only cutting part time right now, so once a week is all I need, but when I go more full time next season these blades would have to be sharpened every one to two days!! That's gonna add up REAL quick. Hell, it already is. I could have already paid for a nice blade grinder by now.

    Not to mention the time it was taking me to drive to the sharpener and wait while he sharpened them and drive home.

    I did buy a bench grinder to hold me over until I can get a dedicated grinder for next season. Not as happy with the edge, but it's saving me alot of time and money for now.

    How many blades are you sharpening and how often? Do the math and you'll see why you probably NEED a dedicated grinder too.
  10. thfireman

    thfireman LawnSite Senior Member
    Messages: 541

    I got a dedicated blade sharpener that normally cost about $375.00 off of ebay a couple of years ago and paid $125.00 plus $20.00 shipping. The thing was like new and works great!;)

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