Wet Vs Dry Drilling

[moomarine]

As the subject says! Can't find a current discussion on this so thought I'd ask. Need to buy some new drill bits and currently use wet diamond bits but am thinking of trying the dry ones. Has anyone got an opinion on which is better and why?

 

[Concrete guy]

It really depends what you're drilling. Assuming this is for porcelain then there is very little to beat the electroplated holesaws and a sponge on a cost per hole basis as they are disposable.

Some of the more expensive water fed systems (like Marcrsits for example) are ideal if you've got hundreds of holes to drill regularly, but can be a bit overkill for the average tiler.

On the occasions when you need to drill dry then there's always a compromise between cost of bit and number of holes it will produce. As a rule of thumb drilling dry is always going to shorten the life of any bit.

Vacuum Brazed Diamond bits designed for drilling marble also work in Porcelain to a reasonable degree. The smaller ones have wax filled centres to disperse heat.

 

[moomarine]

Thanks for response, I get my grinder blades from you so will have a look at your drill bits as well.

 

[Rich Midge]

I tend to put the cost of holesaws into my estimates for bathrooms. I just use whatever the tile shops have in stock at the time but always use a wet sponge. I keep a set of the wax filled bits for wall plug sizes and find them excellent.

 

[J Sid]

did wet for years with no problem, then I tried a dry bit for the grinder and now do all dry.
as for cost per hole I have no idea but find the grinder a lot quicker.

 

[Rich Midge]

did wet for years with no problem, then I tried a dry bit for the grinder and now do all dry.
as for cost per hole I have no idea but find the grinder a lot quicker.

See alot if guys on here using the grinder for holes, something I'm yet to try.

 

[moomarine]

That's currently what I do, just buy from shop when needed and have always been too lazy to get a hand full of them online cheaper.

 

[moomarine]

did wet for years with no problem, then I tried a dry bit for the grinder and now do all dry.
as for cost per hole I have no idea but find the grinder a lot quicker.

I would have to dig out the wired grinder as my 18v Dewalt grinder is only 7000rpm which is too slow I believe for dry hole saws.

 

[J Sid]

don't even own a cordless grinder, can't beat a bit of 240v

 

[moomarine]

I love my cordless! Not had it too long but it's used every day and Dewalt do a massive battery which lasts ages.

 

[Concrete guy]

I would have to dig out the wired grinder as my 18v Dewalt grinder is only 7000rpm which is too slow I believe for dry hole saws.

That would probably do just fine, but a corded grinder would probably do better. Some of the cordless non branded grinders are now so cheap we have a number of customers that bought one just for holesaws and box all their bits in with the cheapie grinder to save taking blades off their their regular machine each time the wanted to drill a hole.

The M14 threaded dry bits are designed to run at 10,000 rpm but we have customers that use an M14 to Hex adapter and fit them in drills. Not recommended but it works, particularly in marble, travertine limestone etc.

 

[moomarine]

That would probably do just fine, but a corded grinder would probably do better. Some of the cordless non branded grinders are now so cheap we have a number of customers that bought one just for holesaws and box all their bits in with the cheapie grinder to save taking blades off their their regular machine each time the wanted to drill a hole.

The M14 threaded dry bits are designed to run at 10,000 rpm but we have customers that use an M14 to Hex adapter and fit them in drills. Not recommended but it works, particularly in marble, travertine limestone etc.

So you reakon 7000rpm would be OK then? What would it do just reduce the life of the bit?

 

[Concrete guy]

So you reakon 7000rpm would be OK then? What would it do just reduce the life of the bit?

I'm not sure it would reduce the life, just drill the holes 30% slower.

The way these grinder bits work is speed and diamonds. Just don't lean on them, let them cut through themsleves.

 

[moomarine]

I'm not sure it would reduce the life, just drill the holes 30% slower.

The way these grinder bits work is speed and diamonds. Just don't lean on them, let them cut through themsleves.

Gotcha!

 

[Stef]

Try Alan's dry core bits for your drill as they work well.