A question for bowl turners....

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Warren White

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....what are the advantages/disadvantages/reasons why you turn an 'innie' or an 'outie' on the bottom of the bowl to attach it to the chuck once you have turned the outside of the bowl?

If it matters, I have a Nova G3 chuck, so I am somewhat limited to the size of material I can either hold by expanding the chuck (the 'innie') or squeeze with the chuck jaws (the 'outie').

My friend is an 'innie' devotee, while I kind of favor the 'outie' hold. Is there a general rule of thumb?

Your thoughts?
 
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JimB

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I think it is more of personal preference but for me I mostly do 'innie'. By doing this, with a recess, i can completely finish the bottom while doing the outside and creating the recess. I can also, if after the entire bowl is complete, easily remount it if I am not happy with something.

I do occasionally do an outie with a tenon. However, I usually do this when I plan on leaving the tenon as part of the foot. The problem is I don't seem to be very good at making a foot that looks good on the bowl. That is part of the reason I use the recess method so I don't need to remove the poor looking foot/tenon.

One other note. Some folks will say using a tenon is safer because you are compressing the wood to grip it. When using a recess you are pushing outwards and have a greater risk of cracking the wood. I have never had this particular problem.
 

D.Oliver

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For the most part, its a matter of preference. I use both but I prefer the "innie" as you put it. I think I use it more often because I'm lazy. I cut the bowl blank at the band saw. Then I put a forstner bit in and drill the hole and slap it on the lathe. Saves the step of putting it one the lathe and turning the tenon between centers and then stopping and switching to the chuck. The tenon (outie) method may waste a little more material, but its bowl turning and any way you look at your wasting a lot of material. It also depends on the type of bowl. I tend to use the tenon method on flat bottom bowls and the innie method for bowls with a bottom. Just my thoughts. There are much better bowl turners than I and hopefully they may have some more insightful comments.
 
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Cwalker935

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An outie gives you better holding power and may work better on softer woods. An innie can split out. I use both depending on what I am doing.
 

Warren White

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Then I put a forstner bit in and drill the hole and slap it on the lathe.

Thanks, Derek. I had never thought of using a Forstner bit, but it sounds like a good idea. However, I think I will do that once the blank is mounted on the screw chuck. Thanks!
 
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mg_dreyer

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The "innie" should not split out if you are leaving more meat on the outside. For example if you are turning a 1/16" foot on the outside then the innie need to be 1/8". That will leave a piece of backing wood that is bigger than the foot and should not split out. If it is the same depth then the force to the side is only backed by the width of the foot.
 

Warren White

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I think it is more of personal preference but for me I mostly do 'innie'. By doing this, with a recess, i can completely finish the bottom while doing the outside and creating the recess. I can also, if after the entire bowl is complete, easily remount it if I am not happy with something.

I think the remounting thing is a big deal. Thanks for the advice.
 

duncsuss

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If the wood shows any sign of checking, I won't use an innie.

If the wood is punky where a tenon would be, I use an innie leaving lots of meat around the outside of it (at least 1.5" thick band around the center hole).

IMO, it all comes down to safety. I've had tenons snap and the blank comes off the chuck, I've had bowls crack open and the blank comes off the chuck. I pick whichever is going to be most secure.
 

Robert Taylor

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as said several times already it is a personal choice. no right or wrong. I personally use a tenon on my bowls and a mortise on platters. I have no problems removing tenons or blending away a mortise. I prefer to leave no trace of how the item was held. only other turners are even going to look or care. buyers do not seem concerned. they only care how the piece looks. I am by no means an expert, just my thoughts. bob
 
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edstreet

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No longer confused....
Incorrect Bob, and others. Here is the proof.

page 8 and 9
http://www.teknatool.com/wp-content/uploads/2016/10/ACC-NOVA-SCROLL-Jaw-Manual.pdf

EXPANDING DOVETAIL OPERATION
Expansion of the jaws into a recess. This function is for bowl and platter turning
where the projection (depth) of the wood blank is not too great. Specific sizes for
each jaw type is stated in that area. Please refer to the Nova Chuck/SuperNova
Chuck manual for information on how to form a recess.
When making a recess it is important to calculate the depth. The recess depth is
an important consideration for maximising the holding power of the jaws,
guidelines under each jaw should be followed closely. The depth of a recess can
be varied according to the size and mass of the workpiece. Larger bowls and
softer woods require a deeper recess. Smaller lids and thin platters generally
require a shallower recess. Always use a recess depth in excess of what is
required. IF THERE IS ANY DOUBT INCREASE RECESS DEPTH.


SPIGOT OPERATION
Contraction of the jaws around a wooden spigot for grip. Mainly used for box,
goblet and vase turning, that is, endgrain items with a fair degree of overhang.
Generally tailstock support is minimal or cannot be used because of the need to
hollow out the inside. This method seems to be preferred by many bowl turners
over the internal dovetail recess as the foot can later be re-shaped or removed, if
desired, to make a smooth outside bottom of the bowl.
This situation is one of the most difficult to provide secure holding no matter what
fixing method is used. EXTREME CAUTION WITH THIS OPERATION MUST BE
EXERCISED. If used properly however the Nova Chuck provides a very secure
grip in this mode.
Check for adequate contact and grip of all four jaws into the wood when using
this operation. MAKE SURE YOU HAVE AN ADEQUATE GRIP BEFORE
OPERATION by vigorously wrenching the work piece mounted in the chuck.
If any loosening occurs DO NOT PROCEED with operation. Repeat tightening
procedure and retest grip. Refer to the Nova Chuck/SuperNova Chuck manual
for information on forming a spigot.


attachment.php
 

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Bob Wemm

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Hey Ed.
It doesn't make any difference what the "Recommended" specifications say, as long as there are humans on this earth there will be accidents, and people will get hurt.
It's up to every individual to do what they feel is safe and use the "GUIDELINES" as a base.
Take a look at the Millions of Dollars that Mining Companies had to spend under "Work Safe" regulations, did it stop accidents???? Definitely not.
For me, if the wood is slightly unstable I never use an "innie", but then I just might, depending on other factors, same applies to tenons.
My 2 bobs worth.

Bob
 

edstreet

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No longer confused....
True. I did show however that one method is substantially inferior for griping and safety standards and if you look at what AAW states on the subject it will be in line with what I posted. However if someone wishes to forgo safety then the blow out or accident is on them and not us.
 

jttheclockman

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I believe there is no right or wrong way that is dead set. There are situations when either or works. Does it make it unsafe. No more than doing it another way. You must know your tools and their limits. You take what safety measure you feel you need to take.

Some people do not like using double sided tape while some people do not like using a vac system. Some people choose to not wear a helmet or even a face shield while some don the entire space suit look.

I can take this to another area I am well familar with and that is the table saw. Some people like myself take the guard off. I choose to use jigs to keep me safe. Does that make me any more of a loose renegade than one who has all the safety shields on. In my mind no because I am aware of the dangers and how I incorporate my safety measures. yet all manuals tell you to keep the guard in place. Just an example.

Whatever you do in your shop just be aware of the dangers and work safely. Use whatever methods gets you to that point and if it feels unsafe it probably is so rethink. Happy turning.
 

howsitwork

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I use whatever I fancy that's safe. Tenons (outie in your terms) allow you to compress wet wood and remount ( if necessary after re cutting the tenon between centres) later. I would always use a tenon if the wood had splits in it ( near miss which bounced off my helmet convinced me of that one).

The dovetail recess allows you to sign in a recess (if you autograph things), it also allows you to leave a rim to rest on so pieces are more stable if they move a bit when finished rather than totally flat.

I agree it's MAINLY other turners who look underneath but hey it doesn't look finished to me if the chucking point, recess is too notable ( pride / prejudice/ preference call it what you want).

If the chuck jaws limit what you can do Hot Glue some sacrificial wood onto the base and cut your recess or tenon on that instead. then turn away the mounting piece by holding between points or plates afterwards. Depends what you're making really.

Have fun but stay safe. Make sure "safe for one last cut" means what it stands for , if you follow me?

Regards Ian
 

Bob Wemm

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I believe there is no right or wrong way that is dead set. There are situations when either or works. Does it make it unsafe. No more than doing it another way. You must know your tools and their limits. You take what safety measure you feel you need to take.

Some people do not like using double sided tape while some people do not like using a vac system. Some people choose to not wear a helmet or even a face shield while some don the entire space suit look.

I can take this to another area I am well familar with and that is the table saw. Some people like myself take the guard off. I choose to use jigs to keep me safe. Does that make me any more of a loose renegade than one who has all the safety shields on. In my mind no because I am aware of the dangers and how I incorporate my safety measures. yet all manuals tell you to keep the guard in place. Just an example.

Whatever you do in your shop just be aware of the dangers and work safely. Use whatever methods gets you to that point and if it feels unsafe it probably is so rethink. Happy turning.

I agree entirely John, The "Recommended" whatever is there only as a guide, it doesn't prove anything.
As long as you feel safe, that is all that's required.
Innie's or outie's , it all depends.!!!!!!!!!!!

Bob:)
 

Lucky2

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It's a matter of preference, which type or style suits you is the one you will most likely use. I've used both methods, and have had good results with each. But, I do prefer the tenon method myself.
Len
 

MTViper

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No responsible manufacturer would recommend a procedure that was patently unsafe. If you go to the chuck manual and look at each type jaw that's available for that chuck, there is a recommended recess depth (expanded mode) and spigot There is also a maximum blank size for each and a maximum speed for each. I use both techniques depending on the blanks and the wood.

I spent 30 years in the safety business and I can smell an unsafe condition. If we use the guards that came on our lathes, wear our safety glasses and face shields (respiratory protection if desired/required), and comply with the manufacturer's manual, we can minimize the chance of an accident. The rest of the safety equation depends on judgment. Therein is the rub usually.
 

Marmotjr

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I can take this to another area I am well familar with and that is the table saw. Some people like myself take the guard off. I choose to use jigs to keep me safe. Does that make me any more of a loose renegade than one who has all the safety shields on. In my mind no because I am aware of the dangers and how I incorporate my safety measures. yet all manuals tell you to keep the guard in place. Just an example.

And even then, guards can make a work setup more unsafe than if they are not there. When ripping down very thin stock, if I left the blade guard on my TS, it would force me to reach up and under the guard and around the kick back fingers to continue to push the piece through. I can't even get a push stick up in there, I'd have to go bare finger. :eek:

So I made a ZC insert with splitters and use a gripper for my thin stock.

Back to the OP, if you're turning a bowl that you don't want a foot on it, you have to go with an Innie. Or else you have to turn the tenon, turn the bowl, then reattach a turned bowl to the lathe somehow to remove the tenon. There are a multitude of ways to do this, but IMO are less safe (generally) than starting off with an Innie. Vacuum chucks can fail, longworths can slip, a donut chucks are only good if you have the right size.

We're spinning heavy solid objects at relatively high speeds, that aren't permanently attached to the chuck, and are natural materials that have a significant chance of failure.

You just have to use your best judgement.
 
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I almost always use a tenon (outie) to attach my bowls to the chuck. I've never come to trust the internal hold very much and I'm more likely to wind up with a funnel than a bowl...

Removing the tenon is not a difficult task... I have cole jaws that will handle most of the bowls I make and if I'm not sure of the hold, I will use strapping tape to hold the bowl on the jaws.

I've only lost one bowl so far and that was in a homemade longworth chuck that was spinning at 450 rpm and a slight catch snatched it out of the jaws and flung it into my face... I sported a black eye for a month... my fault for not wearing my shield.

I will also sometimes use the shop vac and my home made vacuum chucks to hold some of the lighter bowls, but not often. My friend has a small vacuum pump and the hold fast vacuum chucks that works well and will hold even the heavier bowls... I've used his system a time or two and plan in the future to get my own pump.
 

raar25

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Sorry I don't do either. I glue my bowl blanks to a 4" slug which is screwed to a face plate and I turn inside and outside leaving just a small amount of wood to part off at the end. Go back with a fostner bit to make a small recess and voila perfect bottom.

I have always had difficulty remounting bowls with both innies and outies once the material crushes a little from the chuck so this technic evolved and remounting is never an issue.
 

JimB

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Sorry I don't do either. I glue my bowl blanks to a 4" slug which is screwed to a face plate and I turn inside and outside leaving just a small amount of wood to part off at the end. Go back with a fostner bit to make a small recess and voila perfect bottom.

I have always had difficulty remounting bowls with both innies and outies once the material crushes a little from the chuck so this technic evolved and remounting is never an issue.

This sounds like you are using a waste block. It is how I first learned to turn bowls about 8 or 9 years ago. It is a very good system that does not require an expensive chuck, tenon or recess.
 

howsitwork

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Just a thought re vacuum chucks. At the weekend at the club I got talking to a guy who had trouble holding an oak bowl on his vacuum chuck for finishing due to end porosity. So he cling filmed the bowl - worked a treat apparently.

I have not tried it but it might be worth a go WITH GREAT CARE !

Regards Ian
 

Warren White

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I almost always use a tenon (outie) to attach my bowls to the chuck. I've never come to trust the internal hold very much and I'm more likely to wind up with a funnel than a bowl...

Removing the tenon is not a difficult task... I have cole jaws that will handle most of the bowls I make and if I'm not sure of the hold, I will use strapping tape to hold the bowl on the jaws.

I have done the same thing for all but two of my HUGE number of bowls I have turned. (In my case HUGE equals 6 :redface:)

I am more comfortable this was also, and I also have a set of Cole jaws. I think that everything else being equal (which it never is....) I will use the tenon. The little voice in my head just is a bit anxious with the spigot.

I have included a picture of a bowl I just finished for my son in law. It was spigot-turned, but the spigot isn't as nice as I would like. The bowl came off the lathe (no injuries and not any significant damage because the speed was quite low) but I had to clean up the spigot and it wasn't as sharp as I would have liked.

My sincere thanks to all who have contributed to this thread. I have learned a lot!
 

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Warren White

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Sorry I don't do either. I glue my bowl blanks to a 4" slug which is screwed to a face plate and I turn inside and outside leaving just a small amount of wood to part off at the end. Go back with a fostner bit to make a small recess and voila perfect bottom.

I have always had difficulty remounting bowls with both innies and outies once the material crushes a little from the chuck so this technic evolved and remounting is never an issue.

What do you use to glue the slug to the bowl blank? I have heard about wood glue, epoxy, and even (shudder) hot glue.
 

log2lumber

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I turn almost 50 to 60 bowls per year. Outie is the preference because it think the holding power is better.

Either way, you will need to cut the interior or exterior dovetail to match the jaws. For the interior hold, I bought the tool from Nova. For the exterior tenon, I ground a small scraper or bedan to the correct angle and have great holding power
 

Warren White

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I turn almost 50 to 60 bowls per year. Outie is the preference because it think the holding power is better.

Either way, you will need to cut the interior or exterior dovetail to match the jaws. For the interior hold, I bought the tool from Nova. For the exterior tenon, I ground a small scraper or bedan to the correct angle and have great holding power

I have a Nova G3 with the 50mm jaws. While the spigot hold is dovetailed, the tenon hold is square with a bit of a 'tooth' on the outside rim. I don't know how else to describe it. Could you include a picture of the grind on your scraper?
 

nativewooder

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WW, in 2004 we had two hurricanes in the month of Sept., Frances and Jeanne. Needless to say, there were thousands of trees on the ground. I collected wood for 15 months before my car died. For many of them I had to get permission from the State of Florida before it was legal for me to have any of some types of in my possession. A member of our club who is a world-class woodturner and wood artist always told me to locate the #1 jaw on my chuck, mark that spot on the base of the bowl with #1 and always mount the blank with the #1 on the blank even with the #1 jaw. Saved me much time when rough turning blanks.
 

furini

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I turn almost 50 to 60 bowls per year. Outie is the preference because it think the holding power is better.

Either way, you will need to cut the interior or exterior dovetail to match the jaws. For the interior hold, I bought the tool from Nova. For the exterior tenon, I ground a small scraper or bedan to the correct angle and have great holding power

I have a Nova G3 with the 50mm jaws. While the spigot hold is dovetailed, the tenon hold is square with a bit of a 'tooth' on the outside rim. I don't know how else to describe it. Could you include a picture of the grind on your scraper?

I think the instructions for a tenon using this chuck say to cut it parallel and the jaws then grip it tightly with what I think is called a houndstooth...
 

howsitwork

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Warren
Re the question as to mounting bowls on sacrificial blocks. Use newspaper and wood glue- PVA preferable ( titebond type I In USA I think?). You get everything ready first then apply a THIN spread to the bank face, place a sheet of newspaper on top, then apply a THIN spread to the sacrificial block face and quickly apply that to the other side so it sandwiches the newspaper. Lots of clamps and leave overnight to dry.

Once finished turning you put the whole lot on a blanket or something soft so as not to mark it. You then use a sharp knife ( I use an old hand plane blade ) and tap this into the paper joint line. The paper splits and you are left with a finished bowl with a thin layer of paper on the base which simply sands away.

I've made half columns 3ft long for my fire place mantle using this technique and it works really well. No, that doesn't read right - I made 1 column 3ft long then split it to get the 2 that I wanted after turning the beads and routing the flutes along it using a jig I made.

Give it a try, just takes time to prepare as blank surfaces need to be FLAT !
 

MattNZ

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Warren
Re the question as to mounting bowls on sacrificial blocks. Use newspaper and wood glue- PVA preferable ( titebond type I In USA I think?). You get everything ready first then apply a THIN spread to the bank face, place a sheet of newspaper on top, then apply a THIN spread to the sacrificial block face and quickly apply that to the other side so it sandwiches the newspaper. Lots of clamps and leave overnight to dry.

Once finished turning you put the whole lot on a blanket or something soft so as not to mark it. You then use a sharp knife ( I use an old hand plane blade ) and tap this into the paper joint line. The paper splits and you are left with a finished bowl with a thin layer of paper on the base which simply sands away.

I've made half columns 3ft long for my fire place mantle using this technique and it works really well. No, that doesn't read right - I made 1 column 3ft long then split it to get the 2 that I wanted after turning the beads and routing the flutes along it using a jig I made.

Give it a try, just takes time to prepare as blank surfaces need to be FLAT !
This works really well. I also do this with hot glue for smaller bowls, spread hot glue over the waste block with a hot glue gun, then use a heat gun or hot air dryer to melt the glue (your average craft store hot glue gun can't provide enough hot glue in one go, so you need to melt it again), and then place on the base of the bowl, clamping it down. 5 minutes later it's good to go.

Once finished turning, you can heat up a butter knife and push it in between the bowl and the block and it comes off easily. The hot glue usually comes off easily, but if it doesn't a bit of acetone or denatured alcohol gets it off.

I've turned bowls up to 8" using this method. Anything over that and I start to get a bit nervous and revert to my chuck. And besides, for me the whole point of the waste block method is that it works really for smaller bowls and thinner stock, where you really don't have any wood to spare for a tenon or recess.
 

Marmotjr

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Barry

I am really curious - what woods need state permission to possess????

Ian

I've been informed by park officials (in Ohio) that obtaining wood from a State or regional park for "harvest" is illegal without prior permission. They ignore campfire usage, if it's in the park, but they don't want people going into the parks and select cutting, thinking "it's public property".


Also, with the Ash bore beetle killing off the species, they don't want wood traveling too far and continuing to spread pests. Even though that ship has pretty much sailed.
 
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