# Hollowing logs



## Arthropod (Oct 16, 2018)

Hey folks, I´ve been looking for a method to hollow round logs (about 8 inches long and 4,7 inches in diameter) for commercial use. 
Since I want to sell the products, the process should be quite fast and result in a clean hole. My best idea for now is attaching the log on a metal lathe and drill it with a forstner bit. Since I haven`t tried this, do you think it is even possible or do you have any better ideas?

Thx for any feedback!


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## TomCT2 (May 16, 2014)

not sure spinning an irregular chunk that size would be my first thought . . . 

but a bit more info is needed.


is the wood "fresh" or seasoned?
what species? i.e. soft/hard/gummy....

what is the diameter of the hole you want to bore?
does the hole go completely thru the 8 inch length?


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## Brian T. (Dec 19, 2012)

You aren't going to get far attempting to drill a huge hole with any sort of Forstner bit (BIG BUCKS).
They are never sharp enough to do massive end grain drillings.


I use 3/4" Forstners a lot as a rough-out tool in wood carvings = 

drill dozens of holes then bash out the webbing inbetween.


You could do that but you need an extremely long bit shank.



End plate on a wood lathe and turn out as much as you can like a vase design.
How you clean out the bottom is another puzzle.


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## Alchymist (Jan 2, 2011)

Drilling a huge hole with a forstner bit on the lathe - 

1) Use the largest bit to start the hole, going about 1/2" deep, slow and easy.
2) Switch to a forstner bit that's about an inch smaller than the first one, again drill about 1/2".
3) Switch to another smaller bit and drill another 1/2" deep.
By this time you should be down to a size you can drill as deep as required.

Then:
4) Switch back to the bit used in step 2 and drill as deep as required.
5) Switch back to the largest bit and drill to required depth.

Each time you switch back to the next bigger drill, the half inch or so you drilled previously with that size acts as a centering guide. The "cavity" left by the smaller bits allows the bigger bits to cut easier, having to remove less material and giving a place for the shavings to go. You still keep backing the bit out to remove the shavings as you go. You may have to do the first part in more than 3 steps, depending on initial size. If going real deep and with a large large bit, a steady rest near the tailstock will help, providing there is a smooth surface to run on.
Even with all that, a 2 or 3 inch hole 7 or 8 inches deep is going to be challenging. Also works well on a drill press, providing the piece is clamped well so it won't move between steps.


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## FrankC (Aug 24, 2012)

I think we need a bit more information, how big is the hole you are hollowing out for a start. This would be a real waste on a metal lathe, turning wood is a good way to ruin a metal lathe and wood lathes are much cheaper to buy.

Perhaps a drill press would be a better alternative, but as I said we need more info.


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## epicfail48 (Mar 27, 2014)

Well, if you have the metal lathe anyway, no reason you couldnt go through the center with a long 1/2" twist drill, then break out the boring bars and bore to size. Make sure to cover the ways, sawdust and oil dont much mix. Sharp boring bar is a must as well, aluminium specific inserts work great in wood. 

Barring that, any other method depends on how big you need the hole in the center of the log. Large forestner bits are available, but need a good amount of muscle behind them and dont much like end grain. That said, a 4 inch forestner bit is a lot cheaper than a 4 inch twist drill, so its still a viable method id say


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## johnep (Apr 12, 2007)

I'm afraid I would saw the logs in two lengthwise and then stick back together after hollowing out.
johnep


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## Arthropod (Oct 16, 2018)

Wow, first of all thank you all fort the feedback!



TomCT2 said:


> not sure spinning an irregular chunk that size would be my first thought . . .
> 
> but a bit more info is needed.
> 
> ...


So the wood I am using is fresh larch wood. Larch is rather hard but pretty regular in it`s shape so I don`t think it should be a problem for spinning. 
I am planning on diameters ranging between 2,7 to 4,2 inches and yes, the hole should go completely through the whole length. But I could probably decrease the length to 7 inches.





epicfail48 said:


> Well, if you have the metal lathe anyway, no reason you couldnt go through the center with a long 1/2" twist drill, then break out the boring bars and bore to size. Make sure to cover the ways, sawdust and oil dont much mix. Sharp boring bar is a must as well, aluminium specific inserts work great in wood.
> 
> Barring that, any other method depends on how big you need the hole in the center of the log. Large forestner bits are available, but need a good amount of muscle behind them and dont much like end grain. That said, a 4 inch forestner bit is a lot cheaper than a 4 inch twist drill, so its still a viable method id say


I actually just had the same idea from chatting in another forum. Since the other commentators are right, large forstner bits with end grain is probably not the best way to go. 
Do you have any idea which kind of turning tool would be the most suitable for this kind of operation? 






johnep said:


> I'm afraid I would saw the logs in two lengthwise and then stick back together after hollowing out.
> johnep


I thought about this idea myself a lot but I am not a huge fan of cutting up the log and then gluing/screwing it back together. If there is no other way, I will probably go for this method but until then I am searching for other ways.

Thank you for your input tho!


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## TomCT2 (May 16, 2014)

"standard" Forster type bits are not long enough - wood augers are longer.


the four inch diameter is problematic - that's certainly a special tool, but can be done:
line up a whole batch and do it in one go
https://www.timbertools.com/Deep-Drilling-System/


drilling/turning out 4.2 inches of a 4.7 inch log is going to take some practice.
done in green wood, it has a high probability of cracking as it dries.



as to "clean hole"






unless the ends are square&flat and blocked you'll get break out when the drill exits.


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## woodnthings (Jan 24, 2009)

*sawing yes, drilling no....*

You can saw them in half OR you could saw in at one edge, leaving 1" or so remaining, and make complete inside circular cut. Now just glue the single cut back together which is very easily done. Much time saved using this process, but your bandsaw must have adequate height adjustment. Use a 3TPI blade for best results.
I have done this very thing myself:
https://www.woodworkingtalk.com/f13/baileigh-contest-woodnthings-entry-51174/
:vs_cool:


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## Larry42 (Jan 10, 2014)

I'd be inclined to cut them in half lengthwise. Bandsaw. Then glue back. Put them on my MAX oscillating spindle sander and clean up the inside. 
It would be much faster than boring them out on a metal lathe. (I have a 14x40 metal lathe and have turned & bored wood on it. Just the idea of using a 4 jaw chuck on variable shaped "logs" makes me resist. Wood doesn't grip all that well in a metal chuck. The bottom of each log would need to be left and cut off later or the chuck would crush the tube.


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## epicfail48 (Mar 27, 2014)

Arthropod said:


> I actually just had the same idea from chatting in another forum. Since the other commentators are right, large forstner bits with end grain is probably not the best way to go.
> Do you have any idea which kind of turning tool would be the most suitable for this kind of operation?


As large a diameter boring bar as you can get, one that takes either square HSS blanks or indexable with aluminium specific inserts. Anything beyond that depends on the specifics of what you want to do


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## woodnthings (Jan 24, 2009)

*reality check ....*

All you guys suggesting drilling or boring do realize that to remove 80% to 90% of the inside of the log, you will create that much in chips, dust and waste, not very efficient. I suggested sawing it out because I actually did that on my "box from a log" Baileigh Contest entry. It works great and is very efficient. Need I say more?


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## mjadams61 (Jan 1, 2016)




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## Larry42 (Jan 10, 2014)

I thought this over again. I used to make band sawn boxes. I'd use the same procedure for these. Cut the "log" square ended. Bandsaw in from one edge. Remove the center. Glue the entry cut closed. Spindle sand out the center with a very course sleeve, then finer if needed. I've got a 2nd Max sander but don't have all the spindles for it. They are very good machines.


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## TimPa (Jan 27, 2010)

Larry42 said:


> I thought this over again. I used to make band sawn boxes. I'd use the same procedure for these. Cut the "log" square ended. Bandsaw in from one edge. Remove the center. Glue the entry cut closed. Spindle sand out the center with a very course sleeve, then finer if needed. I've got a 2nd Max sander but don't have all the spindles for it. They are very good machines.


 +1 on this method, done it many times. can hardly tell where it was glued back together.


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## woodnthings (Jan 24, 2009)

*We are on the same page ... finally!*



woodnthings said:


> You can saw them in half OR you could *saw in at one edge, leaving 1" or so remaining, and make complete inside circular cut*. Now just glue the single cut back together which is very easily done. Much time saved using this process, but your bandsaw must have adequate height adjustment. Use a 3TPI blade for best results.
> I have done this very thing myself:
> https://www.woodworkingtalk.com/f13/baileigh-contest-woodnthings-entry-51174/
> :vs_cool:





Larry42 said:


> I thought this over again. I used to make band sawn boxes. I'd use the same procedure for these. Cut the "log" square ended. Bandsaw in from one edge. Remove the center. Glue the entry cut closed. Spindle sand out the center with a very course sleeve, then finer if needed. I've got a 2nd Max sander but don't have all the spindles for it. They are very good machines.





TimPa said:


> +1 on this method, done it many times. can hardly tell where it was glued back together.


Nobody reads my posts. :sad2:


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## FrankC (Aug 24, 2012)

woodnthings said:


> All you guys suggesting drilling or boring do realize that to remove 80% to 90% of the inside of the log, you will create that much in chips, dust and waste, not very efficient. I suggested sawing it out because I actually did that on my "box from a log" Baileigh Contest entry. It works great and is very efficient. Need I say more?


I read it, I agree!


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## Alchymist (Jan 2, 2011)

woodnthings said:


> Nobody reads my posts. :sad2:


Don't feel bad, one response to a post I made was "Post 13 came well after initial comments, so it isn’t a relevant response". :innocent:

I just suck it up and move on. :vs_coffee:


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## TomCT2 (May 16, 2014)

perhaps reading is not only fundamental but logamental


"Hey folks, I´ve been looking for a method to hollow round logs (about 8 inches long and 4,7 inches in diameter) for commercial use"


"I am planning on diameters ranging between 2,7 to 4,2 inches and yes, the hole should go completely through the whole length."


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## woodnthings (Jan 24, 2009)

*the diameters are small*

Yes, it may be a challenge with the bandsaw. A 1/4" blade would be where I would start. If that won't work, I still don't know if turning or boring is the best solution because of the amount of waste that needs to be removed. Turning in a lathe is "iffy" because the log is not round to start with and it will compress and come loose in a chuck. I've had that happen when I used a 4 jaw chuck on a wood section. There is no drill that will make a clean "one time hole" that large and that deep that I've seen. 

A cove cut in the tablesaw comes to mind, where you'd slice the piece in half down the length, then run it skewed across the blade. Probably won't get a true radius this way however. The initial cut would be done using a dado set to remove as much waste as possible. 

I just don't see an easy answer to this operation. :sad2:


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## johnep (Apr 12, 2007)

Perhaps use the TS to cut nbr of slots of varying depth and chisel out.
johnep


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## gj13us (Apr 19, 2016)

woodnthings said:


> Nobody reads my posts. :sad2:



Huh?
Did you post something?








:laugh2:


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## gj13us (Apr 19, 2016)

Arthropod said:


> Hey folks, I´ve been looking for a method to hollow round logs (about 8 inches long and 4,7 inches in diameter) for commercial use.



I don't have any ideas better than those already posted. 

But I do have a question. How many of these do you plan to make?


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## woodnthings (Jan 24, 2009)

*If I did, no one would have read it ...*



gj13us said:


> Huh?
> Did you post something?
> 
> :laugh2:


Thanks for asking though.:vs_cool:


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## FrankC (Aug 24, 2012)

With some woods I have found it is better to drill a hole, 1/2" or so, through the center, cut straight into the hole and then from there work out to remove the material chunks at a time.


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