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Being a newbie to DIY and trying to get more and more jobs done myself, safety is a concern to me. I recently bought a Makita 5" angle grinder to cut some metal balustrades, job done. I considered buying some wood cutting discs for it, which I have seen on-line - to do a few odd jobs around the house, but I found some dated Internet posts that strongly recommended against it, for the safety concern, I am guessing that it's for the grinder losing control. These posts where about 5 or 6 years old and from reading through, wood cutting discs were something not available then either. Now I wanted to ask the question again, am I safe to do so or is it a bad idea? Additional information - the kind of jobs I am thinking of using it for, would be mostly softwood and not thicker than 20 mm.

Andrei Rînea
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Ray_Hack
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10 Answers10

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Bad idea...explained later. But yes, as long as you keep the blade guard on & of course it will "work". Though, it's quite wild compared to a Circular Saw or a smaller Trim Saw. However, "safely" is a bad gamble.

You're talking about multiples of higher RPM's & both accuracy & control will then be largely out the window compared to proper devices. One big problem area is ever so slightly twisting your cut (which is normal & not just common with grinders) & that twist binds to instantly & literally toss the grinder at you or any part of you or anyone else close by.

Grinders usually don't have a braking mechanism & very slowly free-spin down to a stop, you don't want to be the braking mechanism.

Iggy
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Warning image of injury

Not safe not smart not at all a good idea. Even with a handle the weight to rpm ratio of an angle grinder make a bind or kick back a near death experience. I came within an inch of losing a thumb yesterday and will never be so careless and stupid again

ChrisF
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Tony Kelpine
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Adding an answer because I happened to see a video on this which has a thoughtful and detailed analysis of why wood cutting / carving with an angle grinder can be so dangerous.

The video also has a "caught on video" moment of such an accident (no real gory details). IMO visualizing such an accident is very healthy mental preparation for this tool (or choosing not to).


My commentary / summary of what I got from that source:

The crux of risk, as I understand it, is this: one edge of the spinning cutter / wheel is moving in the opposite direction from the other. This means that a very small change in tool position can suddenly and radically alter the reaction force on the tool from the workpiece - it "kicks". When this happens you cannot react fast enough to counteract the almost instantaneous change.

Coupled with that effect wood as a material is fibrous and tends to grip the sharp pointed surfaces of cutting devices. This is considerably different from other materials like masonry or metal which are often worked with an angle grinder. A "kickback" type event seems to be far less likely or violent (in my personal experience) in those materials. So one's experience with a grinding those materials seems not to translate very well to using the same tool on wood.


I think the video is excellent overall but here's the key moment where the accident occurs: https://youtu.be/IIQu1e8DGUw?t=288

enter image description here

This example is using a carving cutter, not a circular saw type blade, but the risk seems similar.

(YouTuber: Stumpy Nubs)

StayOnTarget
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No it's not safe at all. I would usually be a safe operator of power tools and all that but recently had an accident using one for the first time which resulted in my getting a deep wound just above my right pelvis. My heavy jacket took most abuse for me (saved me really) but the blade still struck into the side of me and I spent the night in hospital. I was very very lucky the damage was not worse. These blades I think should be banned for angle grinders

Darragh
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Warning, image of injury

Bad idea this happened yesterday as it jolted back. Very dangerous just never get a wood blade for angle grinder

ChrisF
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You might be interested in a door jamb saw...

enter image description here

Ben Welborn
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It works fine, with the correct blade. And the correct blade is critical. But you need to bear in mind, when it's not grinding an angle grinder functions like a circular saw (or plunge saw), in that it will only cut safely in a straight line. Try and deviate from that and it will jam and kick back - in the same way a plunge or circular saw would in the same conditions. If you're working on any remotely 'green' wood a chain blade is the only one to use.

DIYer
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Don't use grinders on wood. They are too light to be controllable. I just got out of hospital after a 4-inch chain disc jumped out of a holly log straight into my right knee. It dug right down to the knee joint - but thankfully missed all arteries and tendons. I have gruesome photos but hopefully my account is gruesome enough

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You can cut the wood using the regular "steel" cutting blades. I use 3mm flat discs with no teeth.

The wood will char at the edges of cut, but if you don't mind the edges slightly burned and the smell, it can be used for small jobs. Mind that when cutting painted/laquered wood, the paint will melt as well, so ensure proper ventillation.

Thomas
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I don't know if this blade design existed when you first asked the question but it seems to me that this would work for demo or very rough cuts. I will use it to cut off Cypress knees.

https://www.amazon.com/King-Arthurs-Tools-35818-Squire/dp/B00004RHL9/ref=asc_df_B00004RHL9/?tag=hyprod-20&linkCode=df0&hvadid=167125219398&hvpos=1o2&hvnetw=g&hvrand=14499310927687167237&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9011791&hvtargid=pla-313102780220&psc=1