Dummies Guide to Angle Grinders and Discs?

[Muggins the Mug]

Hi folks,

I was wondering if any of the more experienced people here (that excludes me ) fancied putting together a "dummies guide to angle grinder and discs"?

It would certainly help newbies like myself avoid the pitfalls in buying useless gear and perhaps what to look out for in decent gear. Perhaps even to suggest how to use the grinders correctly and how to avoid accidents...

Any input would be most welcome.

Regards,

Ian.

 

[daf45]

In an effort to be helpful I'll start... Im a back yard hobby welder not a professional fabricator so take it all with a pinch of salt!

I say (as with all tools) buy the best you can afford, but there has been some debate about the value of cheap grinders here.

The light hobby user might be happy to get started for a while with a cheapo grinder but they don't last long in heavy use. Some of the pro's who do site work treat a couple of cheapos almost like consumables - ie it doesnt matter if they are stolen / burnt out / run over after the job they're on. But in the workshop they all prefer quality kit.

Cheapos like clarke / silverline / big-shops-own-power-latest-chinese-brands can be had for £10 to £20. Mid range would cost about £25 to £35 ie bosch dewalt. Makes with decent reputation including metabo / makita / hitachi seem to be £40 to £50. Note - rough estimate prices for 4 1/2 inch (115mm) grinders, and only my opinion! Do a search on here for more.

PROBABLY THE MOST IMPORTANT POINT when you have decided which one to buy is SAFETY. Any grinder could cut you badly or remove bits of you if used carelessly. Cheapo discs are more likely to break up / splinter. It is well worth spending a minute to put gloves AND GOGGLES on before grinding and probably ear defenders too if it's a propper grinding session. The guard round half the disc not only prevents accidental contact, but will help to stall the grinder if it snatches clothing. Apparently sparks are the biggest hazard when grinding. They are fairly directional and you'll soon see where they're going. Cover glass if your grinding on a car or near the house and make sure the grinding sparks are not heading for your flamables cupboard!

Use the right tool for the job. While Aldis latest jumbos that look something like electric disc cutters may tempt you they will not get in that awkward corner where you neet to cut neatly / grind back to good metal, or tidy up a lumpy weld. ONLY USE GRINDING discs for grinding, and CUTTING discs for cutting. Be extra careful with the wire brush attatchments, they seem to create more gyroscopic force. Flap discs are good for cleaning up welds, and strip and clean discs are (surprise) good for removing paint / underseal.

The experts can now add more about how you are MEANT to use them. Many soft strokes when grinding leave a much better finish than trying to gouge off the excess in one pass. Hope the safety stuff isn't off putting (sadly I find grinding strangely theraputic). If you post specific questions someone will answer.

 

[mongpig]

good idea Ian, will be following this with interest.

just brought a makita and trying to keep all my fingers intact....

rick

 

[shadowcaster]

Cheap tools, expensive tools, obviously the more you pay the better the tools get. However don't write off the cheap stuff, I have 3 grinders, a 9" and two 4" from Aldi and Wickes. As I am on a limited budget they represent good value and work well for me as a hobby user, the 9" is used for cutting/grinding and even with the soft start is a bit of a handful the two smaller ones have flap disk and grinder so I don't have to keep changing disks. I don't howevwe buy cheap disks expearence has taught me that they don't cut as well and certainly don't last as long.

As a final thought a friend of mine who is a self employed carpenter buy really cheap power tools and regards them as disposable but never buys cheap hand tools which he takes good care of.

 

[Chickenjohn]

As another hobby car restorer, I agree with DAF 45, but would like to add on the safety front- in addition to decent goggles and gloves and ear protection, also wear a dust mask, steel toe boots and a decent fire retardent overall (such as Dickes etc). Oh, and some head covering too (could be cotton baseball cap).

Also, don't grind when unwell, tired or under the influence of alcohol.

Have fun!

 

[Muggins the Mug]

Thanks for the input Daf. Whilst experience is a great teacher, some experiences are best not learned the hard way, i.e. losing fingers and getting chunks of flesh removed by improper grinder use - this is where input like yours can help.

I had spoken to Malcolm about having a guide like this, in a PM. He suggested posting a new thread in this part of the forum, in the form of a request.

Regards,

Ian.

 

[irondarren]

Its a good idea. There are so many things you can do (many malcolm has already done in the forum of tutorials) I assume your taking about safety with an angle grinder, and silly things like what does A30BF mean on a grinding disk?. In terms of what grinding disks are best, its a difficult one.
Unless of course manufacturers want to send Malcolm some free samples and i am sure we can bench test them. for durability and material removal

A good thought might be to start a new thread, say what people might like a tutorial for, or a safety tips section on etc etc. That way we can keep Malcolm gain fully employed doing new sections, safety tips and tutorials for the forum. Might save the odd finger or two.

There are plenty of new forum members that join, that have no or very little knowledge of an 'engineering, fabrication' background. I guess thats why they come here to gain knowledge, on the best ways to do things. For those of us that have the knowledge, its easy to share with others.

 

[Muggins the Mug]

Hi Darren,

I hadn't thought about having a too indepth guide, but more a FAQ or "dummies" guide. Grinder safety would have to be top of the agenda though, like getting into a car for the first time - I'd want to know where the brakes are first and if they are working properly.

Certainly talking about different discs for different jobs would be most informative, even going into stuff that some of us haven't used before like flap discs or the large wire brush attachments, etc.

Regards,

Ian.

 

[engybenjy]

sadly I find grinding strangely theraputic

Me too but then I enjoy stickin two bits of metal together aswell !!
Any tips on keeping discs dry or drying discs that were left in a damp shed over xmas

 

[chriskelland]

Hi,

Store discs in something like a plastic box that seals and don't just throw them in the back of the van! Oh and if any disc gets wet, oil /water its ruined, you can't dry them safely. One thing I used to tell guys on my courses was that if you find a bum disc that you don't want to use smash it with a hammer, no one else will get hurt either. I think the difficult bit is for a newby to recognise good and bad discs, I used to carry a whole load of good and bad discs and get them all right and you get an extra fag break!
Anyone got any pics? I binned all mine when I stopped doing training.

Chris.

 

[simon718]

Don't grind while wearing a fleece

yes, i did learn this the expensive way

 

[Bullyterrier]

Wear a full face shield and gloves!
I once thought I would grind a mackerel I was making with a flap disk, without gloves or face protection (I used to do this occasionally being lazy), the disk caught the edge of a fin on the fish and pulled it out of my hand and spun it cutting my finger to the bone.

 

[Muggins the Mug]

Don't grind while wearing a fleece

yes, i did learn this the expensive way

Funnily enough I do wear an old fleece for grinding and welding, but always keep myself out the range of the disc where possible.

Wear a full face shield and gloves!
I once thought I would grind a mackerel I was making with a flap disk, without gloves or face protection (I used to do this occasionally being lazy), the disk caught the edge of a fin on the fish and pulled it out of my hand and spun it cutting my finger to the bone.

Whilst I don't wear full face protection, I always wear eye and ear protection as well as gloves. I used to know a guy that ran a motorbike breakers who was too lazy to wear his goggles one day, that was the day he went to the hospital to have pieces of metal removed from his eye. He still suffered from eye problems months afterwards.

When I was 16 and doing an Engineering YTS, we had it thumped into our heads about using eye protection and why. If we lost a set of eye protectors on the YTS course, we'd get a written warning as they couldn't bill us the £1.75 to replace them (that was 1985 prices). I used to get funny looks off of the neighbours because I always used eye protection using an electric strimmer. You only need to get one small stone hitting your eye to lose it.

Regards,

Ian.

 

[simon718]

that wasn't and old fleece unfortunatly

Also bears mentioning, if others are cutting/grinding around you it can be very easy to get something in your eye, so eye protection all the time in the workshop is a not too bad idea

 

[madkayaker]

with the eye protecting check that they are rated for projectiles some of the cheep ones aren't. Can't remember the code but there as thing about it on arco website

 

[simon718]

is this what you are thinking of mk

 

[madkayaker]

that's the thingy

 

[Muggins the Mug]

My eye protection is rated at EN166 1B, should that be upto the job for use with a grinder?

Regards,

Ian.

 

[irondarren]

leather welders apron boys and girls, thats stops the grinder killing clothes. that arent that expensive either. even cheaper if it saves killing good clothes. Im sure weldequip sells them.

 

[English Steve]

I used to get funny looks off of the neighbours because I always used eye protection using an electric strimmer. You only need to get one small stone hitting your eye to lose it.

Insurance company requires full forestry type headgear when using a petrol one. I thought it was a bit OTT but wore it anyway, and was glad I did after a stone the size of a golf ball hit the shield and dented it.

As a spectacle wearer anyway, I have prescription safety glasses with the side shields. I used to think they were good enough when grinding but have had sparks get in behind them so I wear a full face shield these days. They're not expensive so it's not worth the risk.