Cutting a bigger hole for a Log.

[lw395]

Adding 5mm to the radius of the hole.
A holesaw will likely grab and make a mess.
It may also go blunt before you've done an inch of grp.
I would probably make some radial cuts with a jigsaw or even a pad saw.
Then take out some segments.
Then tidy up with a drum sander. These are pretty cheap in Screwfix.

 

[alan_d]

Starrett hole saws make an arbour that you can mount two cutters the smaller one fits the hole and the larger cuts the new hole, I have done it several times.

Called an "Oops Arbour", I believe. (Google it if you don't believe me.)

 

[Fr J Hackett]

Called an "Oops Arbour", I believe. (Google it if you don't believe me.)

I believe you I have one somewhere

 

[dolabriform]

Thanks all, I went with the Wooden Bung technique.. work a treat

 

[knuterikt]

Adding 5mm to the radius of the hole.
A holesaw will likely grab and make a mess.
It may also go blunt before you've done an inch of grp.
I would probably make some radial cuts with a jigsaw or even a pad saw.
Then take out some segments.
Then tidy up with a drum sander. These are pretty cheap in Screwfix.

what type holesaw have you tested on GRP?

 

[dolabriform]

what type holesaw have you tested on GRP?

Similar to this but wasn't the fast cut version.
https://www.starrett.co.uk/shop/power_tool_accessories/holesaws/fastcut/?item_id=AX5115