Cutting Hardie Board

[vinny186]

I need to cut a large circle from 2 pieces of Hardie board. Which cutting tool/s will give me the cleanest cut?

 

[Snoonyb]

What is the dia. of the cutout?

What is the thickness of the material?

 

[vinny186]

This is to take the place of a glass top that broke. The diameter will be 53" cut from 1/4" thick hardie.

 

[Snoonyb]

Thank you. I would use an angle grinder and first cut some strait lines to the edge of the circle, then around the circles perimeter, and finish with a cement finishing tool.

concrete cutting blades for angle grinder

concrete polishing blades for angle grinder

 

[vinny186]

Thanks for the info and the links. I had no idea hardie board could be smoothed out or polished.

 

[Snoonyb]

There is a learning curve, so refine your talents on some of the scraps.

 

[Sparky617]

Given the structure of Hardipanel that would seem like polishing a turd.

 

[vinny186]

Sparky, are you saying the edges can't be smoothed out?

 

[vinny186]

I should have mentioned this table top will be painted then epoxied. Could have chosen plywood am trying to save my client $.

 

[joecaption]

Unless this is going to be attached to 3/4 plywood, it's not going to work.
Hardie board has 0 top loading strength.

 

[vinny186]

I see what you're saying but it will sit on a metal crossbar and I thought the epoxy would give it additional strength. Otoh, it might be less hassle and more peace of mind just going with plywood.

 

[Snoonyb]

Fewer tools.

 

[joecaption]

Just a really bad idea!
It would be cheaper and faster to just by a new table.
The only time I've seen this work out is when the guy cut out a piece of 4 X 8 X 3/4" PVC to fit.
It worked perfect, but looked like poop.