Finish mower blade sharpening?

[djradz]

Keep the sharpener for a paper weight, but the little balancer is just fine. If you're serious about sharpening, buy an inexpensive 4-1/2" hand-held angle grinder instead of that double sided stone. You should only be sharpening the top side of the blades anyways and just taking off burrs on the bottom.

 

[Anonymous Poster]

I have a Landpride 72"rfm. After blade removal,(3 blades) I
use a carbide paint scraper to remove all debris from all sides
of the blade. After cleaning,I clamp the blade into benchvise
and hand file using a 10"mill-******* file. The advantages of
using a file are,no chance of over heating,easy to maintain
factory angle,least amount of blade metal loss. After cleaning
I can hand-file all three blades in less than 10min. My suggestion is,try it, you may like it.

 

[djradz]

I like the handfile for finishing but I must be hitting to many stones and other small debris because my blades always have bad enough nicks that I'd be at it for hours with just the file, so I grind first and then file. With the angle grinder I don't seem to have to much overheating problem unless I stay for a while in one spot. However, the technique I usually use is to constantly move up and down the blade edge so I'm producing an even surface, ready for finish filing.

 

[Anonymous Poster]

Great thread on sharpening, but first I have to get the blades off! I have a Woods RM90 that has removable covers over each blade for the purpose of accessing the bolts that hold the blades on. The problem is the bolts are from the top down and are not directly over the access holes. To get to the bolts you must reach down and under the access hole and there is no room to add a cheater bar or a large wrench to bust loose the frozen bolts. At best you can get a socket wrench in, but nothing larger. Any suggestions on how to break the bolts loose? I've been sharpening the blades on the mower with a hand grinder, but they need to be replaced and your comments about balanced blades are also a concern.

 

[Chief]

I have tried the hand file method which I would prefer to use but I have found the metal to be so hard that the file barely phases the blade metal. I have tried double cut, single cut, coarse, and fine. I finally resorted to the grinder wheel but that takes a LONG time to properly sharpen the blade at the factory angle without over heating and ruining the temper of the blade materail. What brand file are you using? These blades are harder than woodpecker lips! /forums/images/graemlins/shocked.gif

 

[djradz]

My experience has been that it takes no more than 1 to 3 minutes to sharpen one end of a blade with a 4-1/2" angle grinder when firmly mounted in a vise. I've advanced to now using a portable "Work-Mate" type bench/table and clamp the blade in the table top and then can do the whole process outdoors. If I spend 5 minutes on one end, it had to have been a badly chipped/damaged blade. If your using a bench grinder, I can see where there might be longer times spent in sharpening.

 

[GregJ]

I have a JD LX277 with a Freedom 42 mulching deck. The blades have a curve in them, so they are very difficult to sharpen. I have taken them to the dealer to sharpen and they just butchered them. I found a Dremel tool attachment for sharpening lawn mower blades. It works great for sharpening inside the curves. It's a little slow on the rest of the blade, but the trade off is worth it.

Greg

 

[Inspector507]

Use a 4" grinder on the flat parts and the Dremel on the curves /forums/images/graemlins/grin.gif

 

[GregJ]

Thanks Inspector507. I have a bench grinder and have used it on the flat spots, but it seems as slow as the Dremel, although the Dremel isn't all that slow. After reading this thread I think I'll pick up an offset grinder and give it a try. They have really dropped in price lately.

Greg

 

[Leemac]

Reply to blade removal on RM90. I had a RM59 and now have a RM660. Both of these mowers came with a flat wrench that would lock bolt on top of pulley while removing blade bolt from the bottom of mower deck. I now use an impact wrench to remove blade bolts from bottom of deck without using anything on top of pulley. Maybe you could check with a Woods dealer to see if there is a special wrench for the RM90. Also you might check your private messages when you have time. I sent you one earlier.

 

[pennwalk]

John Deere blades are much harder than any other blades I have. The belt sander does them but it is slow. I try to sharpen the JD blades every 10 hours. They seem to dull and get dings like the other blades. I'm sure there is a good reason why JD made them that way.

Chris

 

[Larry Anderson]

I have an older model Woods RM660 finish mower. This mower came with a spindle lock wrench that fits on top of the pully. My questions are: How do you get the wrench to stay? Does it take two people (one to hold the wrench the other to loosen the bolt? And, are the blade bolts standard (lefty loosy, righty tighty) or left handed?

 

[Turbys_1700]

1. Lift mower.
2. Place jack stands under mower.
3. Get creeper under mower.
4. Use impact wrench to remove.
5. Sharpen with angle grinder affixed to vise.
6. Reattach.
I have never balanced blades. My dad taught me years ago to sharpen lightly and I do. Never had an issue with out of balanced blades. I also do not leave a real sharp edge. They dull quicker. YMMV.

 

[Larry Anderson]

Unfortunately. I don't have an impact wrench (using socket wrench). Are the blade bolts left hand or standard threads (don't want to strip)? How do I get keep the blades from turning while I loosen the bolt?

 

[DJ54]

It's been a long time since I changed blades on my RM 700, (don't use it much anymore) and do recall the spindle lock wrench giving me fits keeping it on. Seems on the outside blades, I could just barely reach to hold it on. Of course, this was while hanging on a chain hoist. The middle..?? Hmmm.., I may have wedged it with a block of wood between the belt and pulley.

Mine has LH threads, and the bolt is a Nylock type. cross drilled near the end, with a nylon insert, so as to make it not back out while in operation. An impact wrench does make it a lot easier to remove. Maybe something to put on the Christmas list..!!

I sharpen mine on the 8" bench grinder, and do prefer to have a pretty sharp edge. To each his own. But as mentioned, grind a bit at a time, so as not to get it too hot, and lose the temper. I always have a gal. bucket of water near the grinder to dip blades in to keep them somewhat cool.

 

[Thomabear]

4-1/2" or 5" grinder with a flap disk is about the easiest thing I've found to sharpen blades. They remove metal fast without overheating the blade and they do a great job on the blade curves. Once you use one you will never go back.