Sunday, March 31, 2019

How to use a sliding mitre saw safely



Mitre saws are incredibly useful machines.  They've come down tremendously in price over the last few years.  20 years ago they used to cost an absolute fortune. You could get cheaper ones but they weren't very good.  Now you can get some that aren't expensive that are absolutely fantastic and do a brilliant job of cutting wood or metal.  They do come in a few different shapes and sizes.  The two that you can see behind me here, that one is a 10-inch that will cut wood, metal and plastic all with the same blade.  You can even put a diamond blade on that and cut masonry.  The one at the back there is a 12 inch that will cut timber or aluminium with a special blade.  So we will look at some of the features of the machines a bit later on.  I'm not going to go into great detail on the machines , but we're going to look at some of the safety aspects of using a miter saw.  There are some people on that use best miter saws and quite frankly they don't have a clue what they're doing.  They're showing you dangerous ways of using them so hopefully this video will help you to make sure that you use it the correct way.  To start off with we're going to look at some personal protective equipment or PPE.  The very minimum PPE that you should be wearing when you'reusing a miter saw is a pair of safety glasses and also some form of hearing protection. These machines are very noisy in use and if you keep using them over along period of time you will end up with hearing damage which nobody wants. There are a couple of ways you can protect your ears you can get pair of earmuffs like that which will offer absolutely brilliant protection or you can use earplugs. I have to admit that I normally have a pair of earplugs in my pocket everywhere I go but if I'm actually cutting metal I do tend to use the ear defenders because they give you better protection.  So for all it's very simple a pair of safety glasses and ear defenders that is the very minimum you should be looking at. If you're cutting wood you should be able to hook the machine up to a vacuum cleaner or a dust extraction unit that will take away the majority of the dust. If not or if you are cutting MDF you definitely needa dust mask, a very good quality dust mask.  The dust particles off that are particularly nasty.  If I am using one of these machines to cut metal or I am cutting masonry on it then the PPE goes a step further. I tend to put the safety glasses on I'll probably also wear a dust mask, I'll put the ear defenders on and also a full face visor.  If you're wondering why I wear a full face visor it's because if I go on site and have to use an angle grinder we have to wear one of these anyway so it's good practice to wear one of these if you are cutting metal or masonry using a mitre saw.  It really does give you full face protection.  Also if I was to cut something that is dusty using this saw I would also put a dust mask on.  So that's the PPE covered we are now going to take a closer look at some of these machines.  If you're using you rmitre saw a lot it is a lot better if you have an actual stand for it. The one I'm pointing out now is the Evolution stand that is a very cheap stand but the quality on it is absolutely fantastic for the money. It's very useful and you can fit virtually any mitre saw on that stand.  Over at the back there we have the Dewalt leg stand.  That is a lotbigger and it's also quite a bit more expensive but again it is a very, verygood quality piece of equipment.  It's always easier using a saw when it's on astand because you have something there to support long pieces of material etc. Before checking the blade for being square or before making any adjustmentsto the blade whatsoever it's absolutely critical that you ensure the machine isunplugged.  One of the first things you want to do before you use your saw evenif it's been stored for a long time they can get banged about and it can adjust them slightly, is to check that the blade is square to the table.  So to do that you'regoing to need a square.  Simply slide that on there, then touch it ontothe blade and that should be completely square. There should be no gap in betweenthere.  If you get a gap you need to adjust your blade.  You also need to checkit this way from the fence at the back to the blade again to ensure that thatis square.  If it's not square in either of those two planes,you're not going to get a straight cut and your mitres will be an absolute mile out. On a lot of mitre saws you will get a port where you canhook it up to an extraction unit.  It's always a good idea doing that, that willtake away the majority of the sawdust when you are cutting.  We're going tostart off by doing a simple cross cut on this piece off 8x2 timber.  So I'mgoing to put it on the machine, ensure it's up against the fence at the back there. Get it exactly where I want it,and then I'm going to clamp that down in position.  That is now firmly fixed to themachine.  There's no danger of that moving anywhere.  So this particular machine is asliding mitre saw these are incredibly useful, but you have to use them correctly. So it's important when you are doing thecut on this machine that you always pull it out as far as it will gobefore starting the cut.  Then you need to get the machine going up to fullspeed before you plunge downwards and then push the machine back.  What you don't want to do is get the machine started and slam it down into pieceworker that will damage the blade and then you'll end up buying a new blade. Also you don't want to set the machine touching the piece of timber before ithas reached full speed because that can also be dangerous, that can also damagethe blade.  So every time you pull it out as far as you can do, get the machine going to full speed, before gently touching the piece of material.  Once you've gone through the material you then push it back into the machine. I have seen some people that have started cutting there, they've gone through the piece of timber and then pulled it back that way, which is very dangerous.  That can give you a kickback.  It's a bit like using a circular saw backwards when you do that, you should never start your cut there and end it back there.  You always start out there and end your cut back there.  So that is the most basic thing and that isvery important when you're using a saw like this.  I've now put some earplugs in, I'm now going to put some safety glasses on, I'm going to switch the vacuum on and then I'm going to make this cut. You will notice when I made that cut that I left the blade in the material until the blade stopped turning.  That is the safest way of using a mitre saw. Although a lot of people quite simply let the blade go up like that because itis still covered by the blade guard when the blade is in the up position.  But ifyou want to be 100% safe you are better off leaving it down in theworkpiece until the blade stops.  So that is a crosscut you can see that that has given us a very clean cut.  I'm now going to do a mitre cut so we need to undothe knob at the front there and then we just need to turn that to whicheverangle we want.  We are going to cut this at about 30 degrees.  So again I'm going to put that in position, I'm going to use a clamp again to hold that down. You do have to be careful when you're doing mitre cuts and bevel cuts because of the position that the blade travels in.  It's not going straight back and forwards anymore so you do have to be extremely careful where you put yourhands when you're doing this.  You are much better off using the supplied clamps if you can do. So that is a mitre cut sometimes you need to mitre a piece of wood which isa bit too big for the machine.  You can't actually stand this up on there to cutit because it's to deep to be cut.  You've no chance of cutting that on there. So that is where the bevel cut comes in so you can simply line the wooddown flat like so.  It's not a good idea to clamp it, you can't always get the clamp in the position where you want it so it can be very difficult clamping the workpiece.  For this demonstration I'm going to clamp this side of the wood. So I'm going to drop that down there, just tighten that up.  I'm now going to ensure that the fence at the back there is out of the way, because this machine will very easily cut through that.  Then just going to undo this lever at the back and I'm just going to tilt the machine over until it gets to 45 degrees.  That's now locked in at 45 degrees.  I can now tighten up the handle at the back there. So that is a bevel cut.  You can also do a combination of a bevel cut and amitre cut at the same time which is known as a compound mitre.  So I'm now going to undo that, I'll just move that around there and that is a compound mitre.  So that has demonstrated the four basic typesof cuts that you can make on a sliding mitre saw.  Any sliding mitre saw will have a maximum amount of timber that it can cross cut but you can often double that if you do a plunge cut and then turn the material over. So it is possible if you have a saw that can cut for example 300 millimeters itis possible to cut a piece of material that is 600 millimeters wide.  Aluminium can be very difficult to cut unless you have a machine like this. This machine absolutely eats aluminium just with the regular blade on that comes with the machine.  The problem is with aluminium is that it actuallysticks to the blade and it can actually start to clog up on the teeth.  So if you do get that problem it's very, very easy to fix. If you are cutting aluminium and the blade starts to clog simply cut a piece of steel using the blade and that will clean off any of the aluminium that has stuck to the teeth on the blade.  I have to point out that not all machines can cut aluminium and steel it's only the Evolution machines that can cut aluminium, steel and wood with the same blade.  You can also cut a groove or atrench in a lot of material by using the grooving stop.  Sometimes called a trenching stop.  That actually limits the depth for which the blade can go toon the machine.  That enables you to cut grooves or trenches in the material. So if you wanted to cut a groove in a piece of timber you can do it very easily using a sliding saw like this but one thing you have to do is you actually have to pack the material forwards like so.  So you have to pack the material away from the fence in the back there because the blade cuts on a radius. If you try to trench that piece of timber you're simply going to cut the shape of the blade in that piece of timber because you're cutting on a radius.  Soyou would have to put a block behind it and then as you cut that piece of timber you've cut a perfectly straight cut all the way through it because you're using the bottom of the blade.  So trenching or grooving is an extremely useful featurethat you can do on most sliding mitre saws. 

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