How to Sharpen Lawnmower Blades

what's going on everyone welcome back to this episode a home but workshop today I'm gonna answer a question that I've been asked a few times recently and that is how the heck do I sharpen my lawnmower blade check it out [Music] if you found that your lawnmower just doesn't seem to be cutting very well or maybe you've noticed the tops of your grass are not nice and even maybe they're kind of torn and frayed after you're done mowing there's a pretty good chance that you may need to sharpen up your blade or possibly replace it so the first thing you're gonna need to do is remove your blade now I'm not gonna tell you how to remove your particular blade because there could be some differences in machines but for the most part they're gonna be held up in there with a bolt right through that you can just get a ratchet on there take your blade off sometimes you may need to take a block of wood and use it to kind of jam the blade so that when you are loosening that bolt it's not just turning the blade around be safe when you're doing this sometimes these edges can be raggedy and sharp it's a good idea to wear gloves especially if you find yourself having to hold on the blade while you're loosening it make sure you pay attention which way the blade is on there when you're taking it off every blade that I've seen has the bevel facing up but I don't dare assume that every single blade is that way if you put the blade on upside-down you're going to end up trying to cut your grass with this flat edge instead of a nice sharpened edge so come on in a little bit closer and we're gonna take a look at this blade and then get a sharpened I'm gonna begin with a visual inspection of my blade I tend to check the end first because based on my experience the end is where the blade really starts to take a beating I can feel on this one that it almost has a knife edge on the end that tells me that this blade is beginning to get worn out and I probably should get ready to replace it now I don't feel that any pieces are gonna fly off of this and cause a dangerous projectile I'm gonna sharpen this one and put it back on I think I can get at least another round or two of sharpening before it gets too banged up but I know that I need to replace this blade so this area right here is the area we're going to concentrate on we need to clean this up get rid of all this chips and put a nice edge on this thing there's a lot of methods you could use to sharpen your blade and not one or the other is right or wrong it's whatever one works the best for you and you're most comfortable with you could start off using a regular ol file this one would require the most work but you have the most control using a file you could use an angle grinder with a grinding disc you could use a belt grinder if you have one of those available there are also stones that you can chuck in your cordless drill that will grind that bevel on there for you now it doesn't matter which one you choose as long as you can safely get a nice bevel on here we're gonna start out and do one of these edges with just a regular file the first thing you're going to need to do is clamp your blade in a vise or clamp it down to your workbench some method of holding it salad while you sharpen it so you're going to need to find your angle once you start filing I'm gonna start off using the flat portion of the file but the other side I may need the half round to get into this little angled portion here once you make a pass or two you'll see where it's starting to cut and you can adjust the way you're holding it from there don't worry if your first few passes are not really at the exact angle you are not gonna damage the blade if it takes you a couple of passes to find the correct angle your file is gonna eventually begin to fill up with shavings make sure you stop once in a while and use an inexpensive file card to clean out the teeth I'll put a link in the description if you need one here I'm using the rounded portion of my file to get into this rounded part on my blade now your blade could be shaped differently there's a lot of different shapes and sizes out there but basically if it already has a factory bevel on there that's the portion you want to sharpen no matter the shape so after a few minutes of work that's starting to get pretty sharp but it's not completely flat and clean along the edge there's still some Nicks and gouges so even though it feels fairly sharp to me we're gonna keep going and get rid of all these Nicks and gouges I want to make sure I have a nice smooth surface depending on how bad your blade is this part could take you a little bit just stay with it and maintain that angle another method for filing that I've had good luck with is called draw filing and that's where you pull the file diagonally across there it seems kind of counterintuitive to what a lot of us are used to in filing but it is a very efficient method for removing material fairly quickly just like the other method you want to find the correct angle but that's fairly easy to do after making a couple of light passes you start to see the marks in the blade where your draw filing you just adjust your angle as you go and make sure you're filing the same angle you want to do your best always to maintain as close to the original angle as you can whichever way you choose to file it eventually you're gonna get that edge nice and smooth and sharp so now all those nicks and gouges are out of there this has got a really nice edge on it I'm not looking for something in razor sharp that's gonna make the blade really delicate these things take a wicked beating but I do want it to be nice and sharp now all this filing leaves a bit of a burr on the underside and we want to take that off now now I'm gonna reposition my blade in my vise so that I can get to the burr on the underside and now holding my file almost flat against the bottom of the blade I'm gonna make a couple very light passes just removing that bird so there we go we've got one side of our blade sharpened now how long is this going to take you that is all dependent upon how bad of a shape your blade is to start with this one in particular probably took me about 25 minutes or so of hand filing so it's not super fast but you're not going to be spending all day doing it either so if all you have is a file that works just fine next we need to sharpen this other side for this side we're gonna use the angle grinder so the grinder that I'm using is nothing fancy this is just your standard four and a half inch angle grinder this is a corded model but if you have a cordless version or any brand whatever grinder you have will work fine for the grinding disc I'm just using a standard grinding wheel nothing fancy you don't want to use a cut-off disc for this a cut-off disc is a lot flimsier and is not meant for this kind of grinding so be safe get yourself a grinding disc they're not that expensive before we fire up the grinder I want to talk just a second about safety grinders throw a lot of sparks sparks can get in your eyes make sure to protect your eyes with some safety glass it's really important sparks in your eyes bad bad bad news right there also it's really loud so make sure you put on some hearing protection also for a lot of operations in grinding is one of them I like to wear gloves I don't recommend gloves for any sort of operation where you're using like a drill press table saw bandsaw anything that can snag the gloves pull your hands in that's a bad idea but since we're working with sparks and hot metal I'm cool with a pair of gloves so let's do this now using the grinder is really not all that different than filing it by hand I'm gonna make a couple of passes to find the right angle I need to be holding the grinder and then I'll just continue making passes doing my best to maintain that angle and just like the file I'm sharpening every area that had an original factory bevel you don't have to go crazy back and forth push really hard with the grinder you're gonna end up with low spots and high spots just make a nice even pass across the surface of the cutting edge if you've got a tricky curves or contour it's okay to make a couple extra passes if that's what you need to do to get that portion sharp continue grinding until you get a nice smooth even surface free of mixing gouges I'm still gonna remove that burr with a file boat so now that you've got your blades nice and sharp can you just slap these back on your mower and go mow your grass no you can't since we're removing material when we're sharpening these there's a chance that one side of the blade could have more material removed than the other and that could cause one side to be heavy and the other side to be light and we do not want that because these things spin at a super high rpm so it's gonna throw the whole machine out of balance and get caused damage to your machine you're gonna tear up bearings you could tear up blades who knows what all is gonna happen really important don't skip this step now to balance the blades the way I do it you're gonna need a scrap of wood post a wall anything that you can drive a nail in I like to use a little finishing nail but whatever nail you have should work just fine I'm just gonna drive the nail a little ways in the wood I'll clamp it down to my workbench obviously if you're using a nail in a post you don't have to do this part now I can just hang my blade on that nail and watch what happens right away you can see what's going on here since this side is hanging lower it tells me that it's heavier than the other side I like to double check that by flipping my blade 180 and putting it back on there we should get a very similar result just on the opposite side of the blade and we do so I need to go back and remove a little bit more material from this edge I want this thing to hang straight across when you have the blade balanced correctly you should get a very similar result no matter how you hang it on the nail you could see some small differences depending on how it sits on the nail but overall it should be almost identical I also like to flip it around and this is how I make sure all of my blades are in balance this is the method that I was shown many many years ago and it is the method that I still use now it may sound kind of old-school on the nail into a board hang your blade on there make sure it's straight and you're exactly right it is an old-school method now some people feel that this is not the most accurate method but that is also why I flip the blade four different ways while I'm sharpening I should get very similar results no matter which way the blade is oriented now there are commercially available balancing tools that rely on a pivot and some sort of a cone-shaped housing that way your blade will balance and those are perfectly fine to use if you want to use those they're very inexpensive I'll even put a link down below in the description if you'd rather pick one of those up instead of using the nail nothing wrong with them but I'm just showing you how I sharpen a blade and it's worked for me for lots of years so guys now with your blade sharp and balanced you're ready to put this thing back on your mower make sure you put it on correctly don't put it upside down and to make sure you snug that bolt down very tight you don't want the blade to come loose and fly off so thanks a lot for watching guys I hope you found this video helpful if you did give it a big ol thumbs up I definitely would appreciate that don't forget links are down below in the description if you want to check that out social media website all that fun stuff thanks a lot for watching everybody we'll see you next time now how in the world is that going what's that it's yeah how's it recording I just turned it on that's very strange I just turned the camera on and it's hard to record me hey how's it going how can I talk about safety if I can't find my safety glasses now where the heck did they go what if we just sold them at the yard sale

Channel: Home Built Workshop

Views: 71,581

Keywords: Home Built Workshop, homebuiltshop, Jeff Baker, sharpen lawnmower blade, how to sharpen a lawnmower blade, sharpen lawnmower blades, how to sharpen lawnmower blades, DIY Lawnmower blade sharpening, lawnmower blade sharpening, DIY blade sharpening, how to sharpen lawnmowers, replace lawnmower blades, file lawnmower blades, how to replace lawnmower blades, how do I sharpen my lawnmower blades

Id: A-v1C1Pupjw

Length: 11min 55sec (715 seconds)

Published: Sat Sep 14 2019