Excavating a deep hole in a log

Earlier this year, we had a large fir tree chopped down and the trunk was sliced into a number of "cheeses", some of which were scattered across the garden on request from Madame.

The subsequent request is to excavate the cheeses to provide a plant holder .

The wood is reasonably dry but my attempts with a drill and the largest spade bit I could find are slow and not effective. A router doesn't reach down far enough. My chain saw is only using (dangerously) the tip. I have contelplated a mini tct wood saw blade in an angle grinder but not proceeded any further.

Faced with a similar problem to similar dimensions (roughly 0.5m across, depth to say 30cm), how would "YOU" proceed.....?
BTW, once one is completed, I have a further 6 to do.....

All ideas welcomed!

Simon

You can get wood caring disks for angle grinders. Might be worth a try. Radom example from web:

https://www.rutlands.com/sp+more-carving-carving-discs-wood-carving-discs-convex-and-concave-100mm-set-of-2-rutlands%C2%AE+r4200

No idea if the product or seller is any good....

Robert.

A multi tool would get you in there but it would be a long job

Weaken the hole with a long drill bit making x50 holes then carve it out with the chainsaw?

Edited By Ady1 on 04/11/2022 11:02:44

A home-brewed ‘core drill ‘ might do the job.

MichaelG.

Find someone with a really big wood lathe.

I would do the job sideways, not vertically btw

I think a large auger bit would chomp its way through. Use a chain drilling strategy to clear the area and then chisel or burn out what's left.

Martin.

25mm SDS+ Auger bit and stitch drill a ring around the diameter hole you want. I would go right through probably coming in from each end as it will be quicker and easier than trying to pig out the waste in the middle. If that is not an option then lots of auger holes to remove as much as possible

Even with an decent size SDS+ drill you will need to apply a reasonable pressure as the screw point will not draw the bit in to end grain as well as it would side grain.

.

By which I mean :

a suitably large diameter steel tube, with slices cut from a TCT circular saw blade welded onto the end.

It doesn’t need to be very accurately, or prettily, made

MichaelG.

Cut the log in half lengthways and proceed from there with the chain saw.

Join up the 2 halves with a few stainless steel screws from the ship chandler.

Perfect job for an adze, or an arbortech carving disc in an angle grinder.

Cut it all the way through and screw on a perforated sheet as the bottom of the “excavation”?

Wood is more difficult to drill into end grain than sideways.
A smaller say 1/2 in standard twist drill will do better than a spade or auger bit. The smaller holes will go in quicker than large holes so overall time saving. be careful not to apply bending pressure to the bit.

Another approach is a circular saw with a small blade. Tack a stop block over to one edge so the saw is controlled and hold it onto the work at 45 degrees, then lower it into the wood, keep moving round and eventually you get a shallow circular bowl, This gives you a better surface to start drilling outwards at 45 degrees, finally chiselling down wards around the rim.

If you can make a starter hole and dry the wood a bit you might be able to start a little fire in the middle and control the burn.

Lots of wood carving disks for angle grinders are available on ebay which are made for jobs like that.

But use with caution as they are very dangerous

Chainsaw, used carefully. a smaller one will be safer than say a 20" one for this job.

Start a small fire in the centre. Extinguish when it reaches the desired dimensions

Thanks all for your thoughts and ideas. I think I will proceed with the wood carving route. My afforts to date using drilling methods have proved laborious and slow, hopefully this will allow some more speed.

Unfortunately lighting open fires around here is strictly forbidden - and whilst I tend to treat such instructions with a certain 'flexibility', our experiences a few years back have encouraged me to follow the rules...this took 4 days to extinguish with 9 water bombers and helicopters plus ground based firefighters and came to around 200m of our house. Concentrates the mind!

Wood carving results will be relayed back to the forum!

Bore a 1” hole and enlarge with a chisel.

regards Martin

I made a nesting box from a log by removing a vertical section, then used a chain saw to hollow out a U shape, then reattached the removed section and added a new bottom piece. But in this case I would tend towards chain drilling with a smaller bit, then use a chisel / gouge to complete the job. Then readd a base with drainage. I have drilled tree stumps to aid rotting, twist drills are best, with a powerful drill.. Perforated metal or plastic would make a good free draining base..

Not the best way to dish out a log as it is more likely split very easily and you will end up with two halves. The only wood ideal for end grain turning is something like Yew.

But if you know a friendly woodturner who has hollowing tools then that would be ideal it could also be done with a sturdy bowl gouge