Resaw a thick bowl blank

[David Wrate]

Over Christmas I was gifted a large spalted maple round bowl blank. It's 6.25" thick and 13" in diameter. I'd like to cut it into two blanks so that I can make two shallow bowls. But It's too big to fit under my bandsaw so my only other option is my chainsaw which seems a bit brutal for the task.
I suppose I could fabricate a jig to hold it on my table saw and cut it partway through and then hand saw the rest.
Any other options?

 

[Dave Landers]

Arranging for a supported cut of a round blank can be tricky. Either on a bandsaw or tablesaw it's going to want to rotate/spin and you have to be able to prevent that.
Lathes are pretty good at doing round. I'd mount it between centers and use a parting tool as deep as you can safely get, then hand-saw thru the rest of it.
I have a straight cutter in my McNaughton coring set, would be my first choice - I could get thru the whole thing with that.

 

[David Wrate]

Arranging for a supported cut of a round blank can be tricky. Either on a bandsaw or tablesaw it's going to want to rotate/spin and you have to be able to prevent that.
Lathes are pretty good at doing round. I'd mount it between centers and use a parting tool as deep as you can safely get, then hand-saw thru the rest of it.
I have a straight cutter in my McNaughton coring set, would be my first choice - I could get thru the whole thing with that.

Oh jeepers. I didn't even think about just parting it in two. Doh!

 

[hockenbery]

What Dave said
If it is true you can Drive it with faceplate so you keep it square without a lot of finagaling

 

[David Wrate]

Yup, thew two faces are pretty coplaner so that's a plus. That's the path I'll take. Thanks gents!

 

[Dean Center]

That's a long way in there with a parting tool. Plus it's partially end grain. You will need to make the groove wider than the parting tool to relieve the side pressure, and going in straight will be difficult, but important. I'd rely on your prior woodworking experience and a good, sharp hand saw for much of the cut. Do you have a rip saw? Or maybe a Japanese pull saw?

 

[David Wrate]

That's a long way in there with a parting tool. Plus it's partially end grain. You will need to make the groove wider than the parting tool to relieve the side pressure, and going in straight will be difficult, but important. I'd rely on your prior woodworking experience and a good, sharp hand saw for much of the cut. Do you have a rip saw? Or maybe a Japanese pull saw?

Thanks Dean, I think I'll part maybe an inch or two in and then hand cut the rest with my handsaw.

 

[Steve Saah]

Thanks Dean, I think I'll part maybe an inch or two in and then hand cut the rest with my handsaw.

I personally use this method as it’s, in my opinion, the best way to both safely accomplish the task and minimize wood loss at the same time.

 

[Kirk Amidon]

One other thought on the handsaw approach - cut a shallow kerf with the saw, say an inch or so deep, then rotate the blank a bit, repeat. idea is that you will be more likely to keep a straight cut than if you simply cut from one position.

 

[David Wrate]

One other thought on the handsaw approach - cut a shallow kerf with the saw, say an inch or so deep, then rotate the blank a bit, repeat. idea is that you will be more likely to keep a straight cut than if you simply cut from one position.

100% @Kirk Amidon

 

[Brian Gustin]

If your lathe turns slow enough, and you have a good quality Japanese pull saw, you could also possibly use the saw as a parting tool (perhaps something to brace the far side of it in case wood grabs, otherwise it yanks saw out of your hands. I've done that on SMALL blanks (1 inch diameter) to get a straighter 90 degree cut through (I had a 2x4 stuck between bed ways for the far end of the saw to butt up against) but I think it would likely be too dangerous on a large bowl blank (saw set will leave you a kerf, but the kerf can tend to close up as the wood moves, and bind on your saw) However that'd give you the least amount of wood loss without a bandsaw.. Alternatively you can make a home made thin kerf parting tool out of a heavy duty hacksaw blade (I bought a 1/16" thick reciprocating saw blade for a big sawzall, mounted it in a handle and ground away the teeth to create the tool's working edge. I also discovered I can swage the metal (mushroom the tip out a little wider than the blade) to create a nice kerf and the tool can do some pretty deep parts (I've gone to as deep as 2 1/2 inches - parts a 5 inch blank.. I am limited due to the available length of the tool - go too deep and you lose leverage.)

 

[Gary Beasley]

Know anybody with a coring rig?

 

[David Wrate]

Know anybody with a coring rig?

I wish! Can't really justify buying one. Can I?

 

[Lou Jacobs]

You can always find justification for a new tool.

 

[Lou Jacobs]

I have a straight cutter in my McNaughton coring set

I also have the straight cutter, although curiously, when I bought the McNaughton set from Craft Supplies it didn’t come with it. The catalog listed all the cutters included the straight cutter, but it came without. When I pointed that out to them they shipped it out to me separately. Heads up to anyone buying the set to determine if it’s being sold “complete” and make sure you get it. Just to clarify, they were not argumentative, just a point of confusion…
Follow up: the kerf on my electric chainsaw (Echo) is actually narrower than the kerf from the McNaughton blade.

 

[Mark Jundanian]

@David Wrate , good advice above on dividing your blank. But as a different perspective I'd point out that really thick ( >4" ) blanks like you describe are rare finds. If it's dry, or stable for storage, you might consider hanging on to it. If it's fresh, then it's probably better to turn it sooner than later.

 

[robo hippy]

I was out of town, but you all beat me to it, a parting tool. I would be very careful with trying to do it on any bandsaw. If you have the McNaughton straight coring tool, that would be your best and safest bet.

robo hippy

 

[Dave Landers]

I wish! Can't really justify buying one. Can I?

So one day, I came home with a pickup bed full of large walnut logs. My wife and I looked at it and we figured it was either like 10 or 12 big bowls. Or I could invest in the coring rig and end up with more than 3 dozen of various sizes. That load of walnut easily paid for my coring set.
So you just need to find a tree....

 

[Doug Freeman]

Another option would be to use a parting tool as deep as comfortable- then use the chainsaw, the kerf providing a guide. Ive done several this way.

I’ve also use a hand saw with the lathe turning slowly (in parting tool kerf). It works as well, but the chainsaw is much quicker and about equal results. Dont think I’ll try the chainsaw with the blank spinning though….

 

[Nathan Roper]

So one day, I came home with a pickup bed full of large walnut logs. My wife and I looked at it and we figured it was either like 10 or 12 big bowls. Or I could invest in the coring rig and end up with more than 3 dozen of various sizes. That load of walnut easily paid for my coring set.
So you just need to find a tree....

I rough turned a 12, 13, and 14" bowl yesterday and the whole time was thinking about how much less mess I'd have to clean up if I had a coring set up. I just looked it up a few minutes ago and for the oneway with all the knives its like $970. Not that its in stock anywhere but still, spend a chunk to make a chunk, right?

 

[David Wrate]

Sadly I don't think my lathe has to oomph to run a coring rig

 

[robo hippy]

There used to be claims that when you got a coring system, you just had fewer shavings. Well, not true! Using a coring system to remove blanks is actually faster than hollowing it out with hand tools, so, the process speeds up a lot, and you end up turning more bowls, so you actually get more shavings.

As for lathe needs for a coring system, you can do it with a 1 hp lathe, but you need a fine touch, and really sharp tools. I prefer at least 1 1/2 hp on 220 volt.

robo hippy

 

[David Wrate]

There used to be claims that when you got a coring system, you just had fewer shavings. Well, not true! Using a coring system to remove blanks is actually faster than hollowing it out with hand tools, so, the process speeds up a lot, and you end up turning more bowls, so you actually get more shavings.

As for lathe needs for a coring system, you can do it with a 1 hp lathe, but you need a fine touch, and really sharp tools. I prefer at least 1 1/2 hp on 220 volt.

robo hippy

Thanks Reed, I have 1.5 HP so maybe it's an option.

 

[Dean Center]

So one day, I came home with a pickup bed full of large walnut logs.

Was that from Boulder or Ft. Collins when they were clearing out all the infected walnuts? A tragedy. And Boulder wouldn't let anyone take the logs for fear of spreading the germ. They buried them all, IIRC.

 

[Dave Landers]

Was that from Boulder or Ft. Collins when they were clearing out all the infected walnuts? A tragedy. And Boulder wouldn't let anyone take the logs for fear of spreading the germ. They buried them all, IIRC.

This was a co-worker's yard tree in Longmont.
I did once get some Ash that UNC knocked down (they didn't bother cutting - just pushed them all down with a dozer). They were trying to deal with the emerald borer beatle infestation. That wood wasn't hit with the beetle yet. Well, not with that beetle - still had lots of other bugs in there.

 

[Dean Center]

This was a co-worker's yard tree in Longmont.
I did once get some Ash that UNC knocked down (they didn't bother cutting - just pushed them all down with a dozer). They were trying to deal with the emerald borer beatle infestation. That wood wasn't hit with the beetle yet. Well, not with that beetle - still had lots of other bugs in there.

Ag people do like their diesels and hydraulics

 

[Doug Freeman]

There used to be claims that when you got a coring system, you just had fewer shavings. Well, not true! Using a coring system to remove blanks is actually faster than hollowing it out with hand tools, so, the process speeds up a lot, and you end up turning more bowls, so you actually get more shavings.

As for lathe needs for a coring system, you can do it with a 1 hp lathe, but you need a fine touch, and really sharp tools. I prefer at least 1 1/2 hp on 220 volt.

robo hippy

I can definitely hollow out a 14” bowl with a gouge faster than I can set up the Bowlsaver and get 2 or 3 cores, but then I have 2or 3 more bowls to turn. A cored bowl set reduces the amount of wood turned to shavings by the volume of wood left of the cores taken - not a heck of a lot with say 1/4” wall t - have to calculate it when I get another round to it.

I have no problem doing ~13” cores with the Bowlsaver on a Nova DVR driven lathe specd at 1.7 hp at 120V (not sure it is 1.7 hp, but it does have more torque vs a vfd at 400-600 rpm, coring speed)

 

[robo hippy]

The coring system that bogs the lathes down the most is the McNaughton. The blades do not have a true/perfect arc in them. Guess that they are bent after profiling, but the tip/last 1 1/2 inch or so goes straight, so the blade drifts to the outside rather than staying on perfect track. With both the Oneway and Woodcut, they are perfect arcs of the circle, so they go fine. Only problem you have is shavings binding up in the cut, or if the core is not centered on the ways of the lathe, then you may need to open up the kerf.

As for walnut trees, there is a 'thousand cankers disease' that has spread from the oak trees to the walnuts. It has taken out a lot of black walnut around here.

I have turned on a DVR a few times, and what surprised me the most was how much torque you get from that motor. Both the Oneway and the Woodcut take a lot more time to set up than the McNaughton.

robo hippy