Hi Les
I use the 5 minute stuff but leave it for 24 hours and then return the item before sanding, the gouge cuts through it just like the wood, you need to make sure it's hard other wise it still turns but it stick to the gouge,
Here I have added brass to the resin to fill a crack playing around the platter is 600mm diameter so the crack that been filled and turned is about 250mm and went all the way through.
Hope it helps
Ed