Bath outlet out of plane

[jrtrrror]

Me again. This turning out to be a nightmare from hell this bathroom. Your help do far has been invaluable.

So, the next issue is one that I may not be able to explain very well. The pictures may not help either.
Just installing the the Mcalpine bath trap and outlet. I needed it because it gave me the height that I needed to enable the pipes to run.
Anyway, when I attempt to tighten it up, the top section keeps pulling up at at angle. When I look at the bath outlet, it's nothing like even. The thickness of the bath is greater at one side of the hole than at the other.
I cut a spare rubber in half (the one that sits underneath the bath) and placed it on top of the whole rubber that is to be compressed under the bath. This helps a great deal, but I'm not sure if it will do. I thought about building up the underside of the outlet opening (at its thinnest point) with plumbers mate to even it out. And then perhaps plenty of silicone instead of the supplied rubber under the flange that sits over the opening within the bath (to seal it to the bath. But I worry about using silicone. Should I really be trying to use the supplied TPE seal?

Did any of that make sense?
Ta

 

[Ben-gee]

Id probably grind/sand/file that from the underside if it’s all fitted and tiled in.

Flap disc on a 4” grinder, then a bit of 120 grit on a block of wood, then i have a diamond “whetstone”.

This solution is not for the faint hearted and requires reasonable skill…

 

[snowhead]

If you're worried about sanding through the base then do the opposite and build up the low side under the tray with Isopon car body filler (other brands available)

 

[jrtrrror]

If you're worried about sanding through the base then do the opposite and build up the low side under the tray with Isopon car body filler (other brands available)

How would I go about this?

If you're worried about sanding through the base then do the opposite and build up the low side under the tray with Isopon car body filler (other brands available)

 

[ShaunCorbs]

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