Drilling holes in laminated glass - possible, sensible?

[Chris Green]

I'm looking into various ways of refitting windows in my boat and one
possiblilty would involve making holes in the glass. I'm wondering how
easy and practical that might be.

It's laminated glass, one can see the internal (plastic?) layer on one
I have removed. Also it cracks in long lines rather like ordinary
glass when stressed, it just doesn't fall apart.

I'd want to drill quite a few 4mm or so diameter holes.

Doing a quick internet search tells me it's quite possible:-

Use a diamond bit

Go slowly

Keep it cool (with water probably)

Protect eyes, hands, etc.

Is it really as easy as it seems? Can one diamond drill do a few
dozen holes or will I need to replace after a few holes?

Any other advice (like don't do it!)?

If I break a window it's not the end of the world, I'll replace with
acrylic. However if I can [re]use the glass it will save me a fe
hundred pounds.

[David]

Post by Chris Green
I'm looking into various ways of refitting windows in my boat and one
possiblilty would involve making holes in the glass. I'm wondering how
easy and practical that might be.
It's laminated glass, one can see the internal (plastic?) layer on one
I have removed. Also it cracks in long lines rather like ordinary
glass when stressed, it just doesn't fall apart.
I'd want to drill quite a few 4mm or so diameter holes.
Doing a quick internet search tells me it's quite possible:-
Use a diamond bit
Go slowly
Keep it cool (with water probably)
Protect eyes, hands, etc.
Is it really as easy as it seems? Can one diamond drill do a few
dozen holes or will I need to replace after a few holes?
Any other advice (like don't do it!)?
If I break a window it's not the end of the world, I'll replace with
acrylic. However if I can [re]use the glass it will save me a fe
hundred pounds.

ISTR that a technique for drilling normal non-laminated window glass was
to get some putty and form a ring on the glass into which you pour
paraffin or something, and you then drill with the bit immersed in the
paraffin.

[John Rumm]

Post by David

Post by Chris Green
I'm looking into various ways of refitting windows in my boat and one
possiblilty would involve making holes in the glass.  I'm wondering how
easy and practical that might be.
It's laminated glass, one can see the internal (plastic?) layer on one
I have removed.  Also it cracks in long lines rather like ordinary
glass when stressed, it just doesn't fall apart.
I'd want to drill quite a few 4mm or so diameter holes.
Doing a quick internet search tells me it's quite possible:-
     Use a diamond bit
     Go slowly
     Keep it cool (with water probably)
     Protect eyes, hands, etc.
Is it really as easy as it seems?  Can one diamond drill do a few
dozen holes or will I need to replace after a few holes?
Any other advice (like don't do it!)?
If I break a window it's not the end of the world, I'll replace with
acrylic.  However if I can [re]use the glass it will save me a fe
hundred pounds.

ISTR that a technique for drilling normal non-laminated window glass was
to get some putty and form a ring on the glass into which you pour
paraffin or something, and you then drill with the bit immersed in the
paraffin.

or a spray of water from a pistol grip spray every so often while drilling.

The small diamond grit edged hole saws make a fairly easy job of it -
just need light pressure, let the abrasive do its thing...

Bit like:

https://www.amazon.co.uk/sourcing-Diamond-Drill-Ceramic-Porcelain/dp/B07MNQW5FX
--
Cheers,

John.

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[Thomas Prufer]

Post by John Rumm
or a spray of water from a pistol grip spray every so often while drilling.
The small diamond grit edged hole saws make a fairly easy job of it -
just need light pressure, let the abrasive do its thing...
https://www.amazon.co.uk/sourcing-Diamond-Drill-Ceramic-Porcelain/dp/B07MNQW5FX

I have used these on regular glass

<https://www.tilerite.co.uk/drills-holesaws/tile-glass-drills/tgd559/>

(Triangular bit of hard metal brazed into a holder) and I'd far prefer to use a
small hole saw.

I think a drill press would make it whole lot easier.

I don't think you will drill several holes in one piece of glass without the
glass being on some sort of backing. Easing through the last bit of glass was
difficult for me...


Thomas Prufer

[Chris Green]

Post by Thomas Prufer

Post by John Rumm
or a spray of water from a pistol grip spray every so often while drilling.
The small diamond grit edged hole saws make a fairly easy job of it -
just need light pressure, let the abrasive do its thing...
https://www.amazon.co.uk/sourcing-Diamond-Drill-Ceramic-Porcelain/dp/B07MNQW5FX

I have used these on regular glass
<https://www.tilerite.co.uk/drills-holesaws/tile-glass-drills/tgd559/>
(Triangular bit of hard metal brazed into a holder) and I'd far prefer to use a
small hole saw.
I think a drill press would make it whole lot easier.
I don't think you will drill several holes in one piece of glass without the
glass being on some sort of backing. Easing through the last bit of glass was
difficult for me...

Thanks both, the specific drill (type) recommendations are really
useful.

I too wonder about the exit from the other side of the glass being the
point at which one is most likely to make cracks. Given that I'm
going to try this on laminated glass I wonder if it's worth drilling
from both sides and thus making the 'exit' into the plastic layer in
the middle.

[Chris Green]

Post by Chris Green

Post by Thomas Prufer

Post by John Rumm
or a spray of water from a pistol grip spray every so often while drilling.
The small diamond grit edged hole saws make a fairly easy job of it -
just need light pressure, let the abrasive do its thing...
https://www.amazon.co.uk/sourcing-Diamond-Drill-Ceramic-Porcelain/dp/B07MNQW5FX

I have used these on regular glass
<https://www.tilerite.co.uk/drills-holesaws/tile-glass-drills/tgd559/>
(Triangular bit of hard metal brazed into a holder) and I'd far prefer to use a
small hole saw.
I think a drill press would make it whole lot easier.
I don't think you will drill several holes in one piece of glass without the
glass being on some sort of backing. Easing through the last bit of glass was
difficult for me...

Thanks both, the specific drill (type) recommendations are really
useful.
I too wonder about the exit from the other side of the glass being the
point at which one is most likely to make cracks. Given that I'm
going to try this on laminated glass I wonder if it's worth drilling
from both sides and thus making the 'exit' into the plastic layer in
the middle.

It can be done! :-)

I bought these bits:-
https://www.amazon.co.uk/SabreCut-SCTBB10-Multi-Material-Ceramic-Porcelain/dp/B0BVKZ5N3R

I had a play today with a cracked window made of the laminated glass I
want to make holes in. It went pretty well, the first attempt was
nearly OK but made a crack as the drill exited. So I tried again and
drlled from the other side once the tip of the drill was poking
through and that worked perfectly. Excellent! :-)

What seems to be required:-
Fairly slow drill speed (slow speed of two-speed cordless is what I used)
Keep it cool with lots of water (keeps the dust at bay too)
Not too much pressure
Drill from the other side to finish