Tips on drilling through bath

[StephenStephen]

Hi all,

I've splashed out on a new bath like this one:
https://victoriaplum.com/product/mode-tate-freestanding-bath-black-1500-x-700

• Twin skinned freestanding bath
• Outer black colour
• Reinforced with fibreglass for rigidity
• Made from high quality acrylic

I need to make a 40mm hole in the outer skin for the waste pipe (not possible to route under the floor, and am a bit nervous about doing so - I've never bought a bath before, let alone on this expensive!
I's assuming my best approach would be to cut from the outside - masking tape, drill a hole, fine bladed jigsaw?
Any thoughts or suggestions would be welcome,

The photo of the underside of the bath:
Top of photo=outer skin (from the outside), middle=waste, bottom=inside view of outside skin

Thank you, Stephen

 

[Diyisfun]

I think I would use a hole saw from the inside.
But no doubt you will get expert advise shortly.

 

[Tigercubrider]

never done it but my first thought.

Holesaw from the outside, far more tape applied than you think, and over a bigger area. Maybe use a G clamp to hold some ply/mdf to the inner surface to stop splintering.

Not sure how it would be connecting but get the route sorted first

 

[StephenStephen]

A holesaw sounds like a better idea, I'm thinking of using one of these: https://www.screwfix.com/p/erbauer-multi-material-bi-metal-holesaw-40mm/32991#BVQAWidgetID
I'm also wondering about whether to go for 44 mm to give myself a little wiggle room and make life a littel easier, (even though the waste going through are compression joints either end).

 

[Tigercubrider]

44 might be better?
The bath will settle when full of water and a body (or two)

 

[Madrab]

Brand new fine toothed holesaw designed for lighting etc a bimetal saw can be a bit too heavy/coarse.

Tape the area first to mark it properly and stop the arbour sliding, use a 3mm drill to make the first hole to direct the arbour if needed. Drill from inside just to start the hole a little then cut all the way through from the outside in, use a battery gun and do it on slow, will avoid the cutter getting too hot and scorching the acrylic.

 

[muggles]

Be aware that doing this will almost certainly invalidate your warranty

 

[StephenStephen]

Brand new fine toothed holesaw designed for lighting etc a bimetal saw can be a bit too heavy/coarse.

Tape the area first to mark it properly and stop the arbour sliding, use a 3mm drill to make the first hole to direct the arbour if needed. Drill from inside just to start the hole a little then cut all the way through from the outside in, use a battery gun and do it on slow, will avoid the cutter getting too hot and scorching the acrylic.

Thank you - very much appreciated

 

[Tigercubrider]

it may not be a concern, but if you mount this too close to a wall/whatever, with just a 40/44mm hole for the pipe, how do you deal with U bend issues?

 

[Razor900]

Be aware that 40mm pipe is closer to 44mm and if you want a fitting to go through it you'll be better off with a 50mm hole.

Keyhole surgery rarely works out in the building trade you will do more damage trying to make the hole bigger afterwards.....

 

[StephenStephen]

it may not be a concern, but if you mount this too close to a wall/whatever, with just a 40/44mm hole for the pipe, how do you deal with U bend issues?

Thanks for thinking of that - my idea is to drop the bath feet into shallow routed blocks, rather than fixing it down, and the connection by the wall is a screwed compression, so I can disconnect behind and move the bath (freestanding) if I need to...

 

[StephenStephen]

Be aware that 40mm pipe is closer to 44mm and if you want a fitting to go through it you'll be better off with a 50mm hole.

Keyhole surgery rarely works out in the building trade you will do more damage trying to make the hole bigger afterwards.....

Oh dear - I've ordered the 40mm Starrett now, and was thinking I could flap sand or grind it out larger if I needed to - maybe I need to get a bit adapter so I can go larger if I need to once I've got the 40mm hole...?

 

[Razor900]

Oh dear - I've ordered the 40mm Starrett now, and was thinking I could flap sand or grind it out larger if I needed to - maybe I need to get a bit adapter so I can go larger if I need to once I've got the 40mm hole...?

It's the difference between pipe and tube.

15mm copper tube is 15mm measured on the outside diameter, (so smaller inside)

Pipe is measured on the inside diameter so 40mm is the actual hole size the outside is bigger...

 

[Tigercubrider]

If the 40 mm is too late to return, I guess you could use a drum based sander on a drill to open the hole up?
Assuming that the outflow is hidden a bit?

you could also turn the hole into a slot curved at the end - again if not visible in normal use?

 

[StephenStephen]

If the 40 mm is too late to return, I guess you could use a drum based sander on a drill to open the hole up?
Assuming that the outflow is hidden a bit?

you could also turn the hole into a slot curved at the end - again if not visible in normal use?

Thanks for this - 40mm holesaw then a rubber drum sander on a drill to open it up worked pewrfectly