Go BottomBest Tool For Sharpening Brush Hog Blades
 | crunch
Join Date: Jan 2007 Posts: 271 Niagara County, NY 
 Pics
|
2010-09-10 173927
I have a nice Delta 8" bench grinder that I use today for sharpening all my mower blades (lawn + brush hog). But I am wondering if I wouldn't do better with an angle grinder. With an angle grinder I don't even have to remove the Brush Hog blades plus I have a flat disk to work with as opposed to a round edge of a grinding wheel.
If an angle grinder would be useful what size should I get? 4 1/2" vs 7" wheel? And I would assume I need at least 7 Amps for 4 1/2. How many amps would I need for a 7" wheel?
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
 | auerbach
Join Date: Sep 2007 Posts: 2168 West of Toronto 
Pics
|
2010-09-10 173929
First slowly and gently (to avoid heating) grind the upper surface, then flat-file the lower face to remove any grinding burrs. (Upper/lower refers to the orientation when mowing.) Servicing a removed blade allows balancing too.
On-mower touchups are easier with a relatively small grinder. A 4.5" is low-cost and big enough. Or a Dremel-type or an air-powered die grinder with a grinding stone. Electrical tools show the amps on the label.
Whether the cutting bevel is straight, convex or concave doesn't matter much, and if it did, you won't get it regular and perfect with a hand-held grinder.
Grinding to a knife edge allows cutting that's easy on the grass and the engine. But the sharper the edge the shorter it lasts, so most pros want a cutting edge around 1/32 or even 1/16" thick. ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
 | kthompson
Join Date: Oct 2005 Posts: 5275 South Carolina
Pics
|
2010-09-10 173930
I have used the bench grinder and a 4 1/2 angle grinder and greatly prefer the angle grinder. But the tool that I really like the best is a large belt sander. Now you are talking about rough cut blades (think that is correct) and I have never sharpen those, only on finishing mower. If you are able to access them on the mower still think you will have to be able to lock them from pivoting. The problem find with the angle grinder is you need the blade flat for sharpening but a vise holds them vertically or wants to so I normally use a C clamp on a work bench.
One point on the cutting edge on rough cut mower and don't take this as being a sure fact but have been told you want an edge there that does not slice brush to prevent sharp stubble. ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
 | Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
Pics
|
2010-09-10 173939
We use an angle grinder, but we remove the blades from the mower to do it, trying to hold a floppy, rotating blade while you hold the grinder (a job that usually requires 2 hands) is a royal PITA!
If you look under your bush hog there is almost always a single small bolt that goes through the output shaft of the gear box and holds the blade carrier on that shaft. If you undo it, the whole affair just slides down off the shaft.
We then put them vertically in a vice and use the grinder on a 45° to the blade which leaves the grinder in a very natural position, and gives an excellent view of work while directing the sparks up & away from the person doing the work.
If your bush hog has a 'stump jumper' (a round plate under the blades) there should be a hole in ht e upper deck which lets you slide a socket down through to remove the big bolt holding the blades in place.
Either way you do it, it will be easier than sharpening the blades while they're on the machine, that is a nightmare!
Best of luck. ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
 | greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky 
Pics
|
2010-09-10 173945
Bench grinder wheels are fine for finish mower blades, but mine're too soft for rotary cutter blades. I tried angle grinder sharpening ON the machine, I tried sharpening OFF the machine (in a vise). Definitely prefer sharpening ON the machine. Removing and reinstalling the blades (or blade carrier) just wasn't worth the effort.
The issue of holding the blade in place while sharpening on the machine can be overcome several ways. At first I'd simply put a piece of 2x4 behind the blade, bracing it against the inside of the housing. But the 2x4 would fall out occasionally. So I went to the toolbox and grabbed a vise grips. I snapped it to the side of the housing to stop the blade.
A 4-1/2" angle grinder is ok if you remove rotary cutter blades and sharpen them in a vise. But it simply takes too long if you're sharpening on the mower. A 9" turned out to be far too heavy. I found the 7" grinder and the vise grips to be perfect combination for sharpening on the machine.
//greg// ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
| crunch
Join Date: Jan 2007 Posts: 271 Niagara County, NY
Pics
|
2010-09-11 173948
Lots of great responses! Thanks for all your comments. I am partial to getting an angle grinder so will keep looking for a good deal. ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
| auerbach
Join Date: Sep 2007 Posts: 2168 West of Toronto
Pics
|
2010-09-11 173949
I've seen them for $20 and change. It's a handy tool; with the right blade you can grind or cut masonry or metal. But on-mower I prefer something more compact and easier to guide and sends the sparks more along the blade and less at my face.
For season-end remove them for servicing and clean the deck underside and oil it and the blades. The recommended bevel angle is around 45 degrees but isn't critical. If and when you lose the factory bevel and don't trust your eye, bring one or more to a sharpening shop so you'll have a guide.
KT: Never thought of the belt sander but makes sense. What grit do you use? ....
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
| greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky
Pics
|
2010-09-11 173950
|
Quote:
|
//greg// ....
Link: 7" angle grinder
Reply to |
Quote Reply |
Add PhotoBest Tool For Sharpening Brush Hog Blades
| kthompson
Join Date: Oct 2005 Posts: 5275 South Carolina
Pics
|
2010-09-11 173951
auerbach, Think thy are 80 grit. I am using a 6 wide stand belt sander. For finishing mower blades it does a good job. A friend who ran a saw sharpener shop used a about a 1 or 2 inch belt sander for sharpening for such is probably where I picked it up from. ....
Reply to |
Quote Reply |
Add Photo
Go Top
Share This