Wet cutting stone with small grinder

[mtt.tr]

I've had to...and still have some to do...cut a few inches from concrete gravel boards, reduce the height and the length, about 30 of them...yay.

I clamped a peice of angle to act as a straight edge and stuck the hose in one end. Just enough to wash the cut line out and suppress the dust.

Rubber gloves and a 9 inch grinder and make shift diverter to stop it sucking in any water.

Only got a little tingle....

That's just stupid

 

[8ob]

Started in a mini at 8yo. Progresses to telehandlers and dumper trucks then small trucks before doing my driving lessons in a clio. Felt tiny.

Roger!

 

[grim_d]

That's just stupid

Nah it's fine, I've got good life insurance.

 

[gaz1]

use water at your own risk when cutting concrete slabs more so with electric grinders

however battery operated ones are using water suppresion systems just like the big petrol grinders

http://www.brickworker.co.uk/PPE.htm

 

[eLuSiVeMiTe]

Roger!

Odd.
I posted that after this post in the smart motorways thread.

 

[Parm]

Dry cutting of masonry is an instant Prohibition Notice, no questions asked.

The risk of exposure to respirable crystalline silica (RCS) is just of the scale

Recently a I’ve been looking at artificial stone, this has an RCS content of almost 100%, about 4 times higher than natural products.

Information coming out from Australia, (where it’s used much more than natural products) indicates there’s rapid on set of silicosis from short duration exposure

 

[Pete.]

That's just stupid

Depends on what you do and what you use. Some gear is fitted out for wet cutting but most of it will suck in the water/slurry and blow it into the switch void. If you're using 110v gear your biggest potential to earth is 55v which is safe enough for this purpose. You can use a mist spray to control dust and the electrocution risk is minimal. In fact, if you have a good enough control over the water flow and the guy on the trigger is skilled enough to keep a steady load on the cut you can cut with no airborne dust and nothing but a snotty mess to clean up so no water off the blade either, but all that depends on the skillset of the operatives.

240v gear is another matter. the electrocution risk is much higher and if you're using 240v the chances are you're a novice and probably flooding the cut with water. This gets sucked up by the cooling fan and ends up flooding the handle which gives you a shock nasty from the trigger switch.

For small jobs of a few minutes it's probably ok. In any case, it's hard on the gear. I've had to jetwash stuff with clean water before and leave to thoroughly dry out because the switch was so clagged with slurry it wouldn't even return. If you're working anywhere near salt water say on a dock side - forget about it. You're risking your life then.

 

[grim_d]

Depends on what you do and what you use. Some gear is fitted out for wet cutting but most of it will suck in the water/slurry and blow it into the switch void. If you're using 110v gear your biggest potential to earth is 55v which is safe enough for this purpose. You can use a mist spray to control dust and the electrocution risk is minimal. In fact, if you have a good enough control over the water flow and the guy on the trigger is skilled enough to keep a steady load on the cut you can cut with no airborne dust and nothing but a snotty mess to clean up so no water off the blade either, but all that depends on the skillset of the operatives.

240v gear is another matter. the electrocution risk is much higher and if you're using 240v the chances are you're a novice and probably flooding the cut with water. This gets sucked up by the cooling fan and ends up flooding the handle which gives you a shock nasty from the trigger switch.

For small jobs of a few minutes it's probably ok. In any case, it's hard on the gear. I've had to jetwash stuff with clean water before and leave to thoroughly dry out because the switch was so clagged with slurry it wouldn't even return. If you're working anywhere near salt water say on a dock side - forget about it. You're risking your life then.

I'd like to think I'm savvy enough to recognise and minimise any risk....and I'm the guy that flips the main breaker to change something in the house rather than just isolating the circuit.

Just enough water to minimise and wash away the dust, the guard positioned in such a way that the water runs back down onto the job, big pair of heavy rubber gloves and keep a close eye out for any stray water.

Not really any different from working in the rain...but then...that's stupid too.

At the end of the day...it's my life and I'll do what I want in my own garden.

 

[pedrobedro]

Roger!

I've cross posted a few times and it does make you wonder what's happening sometimes

 

[Pete.]

I'd like to think I'm savvy enough to recognise and minimise any risk....and I'm the guy that flips the main breaker to change something in the house rather than just isolating the circuit.

Just enough water to minimise and wash away the dust, the guard positioned in such a way that the water runs back down onto the job, big pair of heavy rubber gloves and keep a close eye out for any stray water.

Not really any different from working in the rain...but then...that's stupid too.

At the end of the day...it's my life and I'll do what I want in my own garden.

Man I can only agree with that. Some people can handle fire, others will burn themselves looking at it on the telly. Aptitude counts for a lot.

 

[mtt.tr]

Depends on what you do and what you use. Some gear is fitted out for wet cutting but most of it will suck in the water/slurry and blow it into the switch void. If you're using 110v gear your biggest potential to earth is 55v which is safe enough for this purpose. You can use a mist spray to control dust and the electrocution risk is minimal. In fact, if you have a good enough control over the water flow and the guy on the trigger is skilled enough to keep a steady load on the cut you can cut with no airborne dust and nothing but a snotty mess to clean up so no water off the blade either, but all that depends on the skillset of the operatives.

240v gear is another matter. the electrocution risk is much higher and if you're using 240v the chances are you're a novice and probably flooding the cut with water. This gets sucked up by the cooling fan and ends up flooding the handle which gives you a shock nasty from the trigger switch.

For small jobs of a few minutes it's probably ok. In any case, it's hard on the gear. I've had to jetwash stuff with clean water before and leave to thoroughly dry out because the switch was so clagged with slurry it wouldn't even return. If you're working anywhere near salt water say on a dock side - forget about it. You're risking your life then.

This is based on assumption, neither poster mentioned they are running 110v. Which the potential is U110v but has a Uo of 55v

And its not that i haven't done similar, i have a wet kit for my worm drive saw. Diy version of this:

https://omegadiamond.com/948-421/Blue_Ripper_Jr_Rail_Saw
. I just don't approve suggesting possible dangerous options on an open forum.
After all people are stupid.

 

[eLuSiVeMiTe]

I've cross posted a few times and it does make you wonder what's happening sometimes

Recon it's my phone. Occasionally fits out and backs to a previous page unintentionally.
Though I always click reply rather than quote so don't know how that happened.

 

[Pete.]

This is based on assumption, neither poster mentioned they are running 110v. Which the highest potential is 110v but has a Uo of 55v

You can't get a 110v shock from a wet handle, you'd have to have a different part of your body in contact with each conductor to achieve it. 55v to earth is your worst and the reality is likely to be a lot less. Read on and you'll see where I said "240v is another matter" and qualify that too.

Wet concrete cutting is my trade, has been for many years so I do speak with some authority on this.

 

[grim_d]

I didn't really suggest that they do it, just saying that's what I did. Adults are free to make their own choices, and should risk assess anything they do, if they decide to be a moron...well that's Darwinism.

On a serious note @Ali depending on what your cutting, kerbstones, slabs, natural stone, they can all be cut accurately and neatly with nothing more than a bolster and a club hammer, just takes time.

The stuff with the bigger aggregate like dense blocks are harder to keep neat.

 

[mtt.tr]

You can't get a 110v shock from a wet handle, you'd have to have a different part of your body in contact with each conductor to achieve it. 55v to earth is your worst and the reality is likely to be a lot less. Read on and you'll see where I said "240v is another matter" and qualify that too.

Wet concrete cutting is my trade, has been for many years so I do speak with some authority on this.

The point i was making was that 110v can still give you a 110v shock very unlikely but the potential is still 110v (U line to line voltage) the potential to earth as you rightly stated is 55v (potential to earth)


there is this idea that 110v is perfectly safe, nothing is perfectly safe!
wet cutting concrete doesn't change the physics applied

 

[Pete.]

55v can be regarded as safe in that nobody has ever been killed by it (simply by contact with it).

 

[dannyp]

when your grinder has had a dunk in saltwater, and you pick it up becasue its fine because its 110v. it recalibrates your opinion of 110v it dosent trip ot tho makes your eyes light up as well

 

[Pete.]

Salt water makes it spicy but it'll still be only 55v. I've dropped my mini-grinder many times working in tidal water. Getting a full 110v shock carries about the same odds as getting run over by a car and a train at the same time.

110v site supply is never going to trip out from giving you a shock because it's not earth leakage protected.

 

[grim_d]

If you used pure water, as in nothing but H2O, would that make it safe? Or would you immediately ruin it's insulating properties by contaminating it with masonry dust?

 

[Pete.]

Distilled water doesn't conduct. Dunno about the dust. I've washed salt water out of electrical tools with a jetwash and tap water and left them in the drying room to evaporate out. They don't like too much of that and some tools with the 'intelligent' switches can throw a paddy for days. Makita 5" grinder - no problem. Hilti TE drill - don't do it.