"Push cut" help wanted.

[Dan Forman]

For any of you who use the push cut method as taught by Ashley Harwood, Stuart Batty and others, how do you address the lower outside portion of a dried, warped bowl when first re-turning it? I don't see how to use a push cut on the lower 1/3 to 1/2 of the outside, as it doesn't seem possible to present the tool properly due to interference from the tailstock, Thanks in advance if you can clear up my confusion on this issue.

Dan

[Faust M. Ruggiero]

Dan,
I've seen the push cut demonstrated by SB but he was turning a green bowl mounted on a screw chuck so there was no tail stock to impede him. The only to use a push cut from bottom to top is with a screw chuck, which does you no good when second turning, or mount a piece to be second turned in a vacuum chuck. I use a push cut whenever possible because it gives me a clean finish and since I am right handed keeps me out of harms way. However, until I establish a trued area on which let the bevel ride, I still begin across the bottom with a scraping pull cut. Mounting a roughout on a vacuum chuck requires an additional step. I begin second turning by mounting the bowl with the inside facing the tail stock. I extend my tail stock into the inside of the bowl with a Morse taper extension. I've learned to leave a center mark in the bottom inside of the bowl when I rough turn. This makes finding the center easy. The Morse taper extension leaves me enough room to true a section of the bowls inside so that area will sit true against the vacuum chuck when I turn the bowl around. It's awkward but it works. Then I turn the bowl around and turn on the vacuum and work free of the tailstock. I don't work this way just to use a push cut. I find the bowl had less vibration mounted this way since the vacuum chuck meets the bowl at least a third of the way up the side. When the outside is finished and sanded, I turn it around and cut the inside.
I'm sure you were not looking for such a long answer but it does solve your question.
faust
faust

[Reed Gray]

I find that push cut method confusing, mostly because I use the sliding headstock pushed all the way down to the end. I still push cut, but have the handle close to my body. It is one method, on a long bed lathe that keeps you from having to bend over. Oh, my aching back! Been there and done that. Ain't gonna do it again.

For a twice turned bowl, when it is dried and ready to turn again, common method is to true up the tenon first, then reverse and finish turn. You may be able to slightly true it up before you reverse, but I don't think any one does that. I am guessing that you meant headstock above because, with the inside removed, the tailstock is generally not engaged. I will use a scraper at a shear angle to nibble off the bottom part of the bowl and true it up. Not to hard to get it in there for that cut. It is pretty close to impossible to get a bevel rubbing cut that close to the headstock, even if you use extended jaws, especially if you use the 40/40 gouge. Once I get out a little way, I switch to one of Doug Thompson's fluteless gouges with a 70 degree bevel. Kind of like the transition on the inside of the bowl, the steeper bevel helps you get in that tight spot. Once you get out a ways, then the more standard bevel angles will work. Another way to do it is with a standard gouge, and swept back wings. Drop the handle, roll it over till it starts to cut, and you do kind of a push cut. Instead of pushing just with the handle, you push with both hands (handle and shaft). Maybe kind of like doing a pull cut, but you are on the other side of the gouge and pushing rather than pulling.

Hope that explains at least a little. One advantage to my warped bowls, turn it once and done.

robo hippy

[Reed Gray]

I went to You Tube to see if I could find some one turning a dried blank, and couldn't find it. I know it is in Mike's videos though.

robo hippy

[Mark Levitski]

I'm not exactly sure how you are having access trouble with this cut from the tailstock side. Usually this question comes up when the cut is attempted from the headstock. I guess my advice would be to push when you can push, if that is the cut you wish to make. If not, then pull cut. Initially I return the lower portion of a dried roughout bowl when I true up the tenon for rechucking The access is OK for me then for a push cut from the tailstock once you get far enough away from the transition to the tenon. Or you can pull cut the first portion when you get it back into the chuck after truing the tenon. However, I always actually finish that portion when I do the final reverse for finishing the bottom.

Type of lathe, tailstock configuration, and tool bevel angles might have an effect.

[Dan Forman]

My process in the past: I place some 80 grit sandpaper over the jaws of my chuck, and used that as a jamb chuck, inside the bowl, brought up the tailstock, and trued the tenon. I usually go on to true up at least the bottom half of the outside of the bowl (using a pull cut), if it feels good and stable, will sometimes do the entire outside up to the rim and sand, before reversing the bowl in the chuck and turning the inside. That part of the operation is not possible using the push cut and a 40 degree grind, due to interference from the tailstock. My main interest in the push cut is the unbelievably clean surface it leaves. This is really only important on the second turning, which is why I'm trying to figure this out. I use a vacuum chuck to turn off the tenon and finish the bottom.

In Ashley's demo, she turned a bowl green to finish, so she didn't have to perform the truing operation. At the end, she did reverse the bowl and pressed it on a jam chuck that fit along the rim, and was able to remove the tailstock and take a final pass all along the outside using a push cut. This requires a pretty steep entry into the bowl, which doesn't suit all forms, and is a step I'd rather not have to mess with for a number of reasons, including lack of storage space.

Faust --- My experience with vacuum chucks is that it doesn't take much force to knock a piece off center, which seems as if it would be easy to do while truing up a warped surface. I generally only use it for removing the tenon after everything else is done. Times that I've tried to use it to correct a problem after the tenon is gone have usually not gone well. The farther out toward the rim you work, the greater the forces are to knock it off center. When you turn the area (inside) for the vacuum chuck to seat on, do you make it like a groove which supports the inside and outside edges of the chuck to prevent the piece from sliding off center? Also, wondering why you need to mark the inside of the bowl and use the tailstock, if you have already trued up the tenon, I assume you would use it to hold the bowl while you level a place for the vac chuck to seat against on the inside. :confused:



I'll have to see about tools with steeper bevels for this critical area and see how that works out. In the meantime, keep the information flowing folks.

Dan

[Dan Forman]

Reed --- I wish you would do a Youtube video of how to use the fluteless gouge. I have one, but find it hard to control on the inside of a bowl, it seems to want to go ever deeper when I'm trying to take a shallow pass. Never tried it on the outside, but will see if it will help. I'm sure it's a flaw in my technique, it would be really helpful to see it in action. Hint hint. :)

Dan

[Bob Hamilton]

I do the initial truing up of the tenon and truing and shaping of the outside of the bowl with the tailstock in place. You're right, you can't use a push cut on the lower third with the tailstock in the way. I then mount the bowl in the chuck and do the finish turning of the inside so the inside is complete. I then reverse it on to a vacuum chuck but leave the tailstock in place until I have removed the bulk of the tenon. I then turn on the vacuum, move the tailstock out of the way, and do the final finish turning of the outside and base. I take a light push cut up the bowl wall from the foot to the rim for my final surface, and then remove the center nub and clean up the base. I have not had a problem with the bowl shifting off center when making the push cut up the side wall, but that is why I leave the center nub until after it is complete, so I can re-center it if it does slip. It seems to me that the only times I have had a bowl shift off center was when I was cutting across the base towards center and trying to advance the tool too fast as it encountered the slower moving wood near the center. At those times the cutting pressure is at right angles to the turning axis of the workpiece. When doing a push cut from foot to the rim the tool pressure is mostly parallel to the turning axis and towards the chuck, so should not push the bowl off center.

I prefer to use a vacuum chuck that is small enough in diameter to enter the mouth of the bowl and seat on the bowl walls 1/3 to 1/2 of the way down. That extra support on the inside of the bowl walls really seems to make it easier to get a good surface on the outside.

The method I use is shown starting at about the 10 minute mark of this video: http://www.youtube.com/watch?v=DDnSG0N6Tog

Take care
Bob

[Reed Gray]

Dan, if the cut is going deeper, you need to move the handle angle more towards you more, just like a standard gouge if the cut is going too deep. I tend to have the cut go too shallow, which means I need to move the handle angle more away from me. Just like a standard gouge cut. It really is the steeper bevel angle that throws us off, since it is a specialized tool and we don't use it as much as our standard gouges. The bottom feeder type gouges also give me some problems for control. With the fluteless gouge, I usually drop the handle because it cuts like a skew (Dave Hout called his version a bowl skew, same basic tool as the Tracy Owens one that Craft Supplies carries) and with a skew, you cut with the bottom/lower 1/3 or so of the cutting edge.

I am not sold on the idea that the 40/40 bevel and push cut give you the best surface. To me it has more to do with shear angle, and rubbing the bevel. If you saw my finish cuts with the spindle roughing gouge clip, that leaves a beautiful surface. My personal results vary a lot, and I figure that is more the driver than the tool.


I will get a few clips up on the fluteless gouge. I really like it, on bowls and on spindles for coves and rolling beads. Yes, I do a few of those.

robo hippy

[robert baccus]

Every one has their fav. but I have always had to go to a push cut for a good finish cut. (3/8" BG). In fact that's the only way I used a gouge for 5 years. If you are without a vacum chuck make an extension to go in the chuck. I use a 1/2 " ID black pipe with a padded block on the end that goes inside the bowl or vase. Bring up the tailstock and it is locked in. By using several lengths you can do bowls to 20"+ vases. I can't think where I would use a vacum chuck if I had one really.

[Mark Levitski]

I agree w/ Reed. Skew will give you a very good surface too. Would you wanna use a skew in that situation? No, of course not. So, sometimes you can push a gouge along, and sometimes you can't. When you can't and you still want a good surface, then try using something else rather than trying to adhere to a certain formulaic or popular technique that doesn't quite fit the situation.

Dan, have you tried using a bowl gouge with a longer wing in a shear cut? The shear angle is steep, the cut creates a very nice surface, and you can get in pretty close to the foot near the tailstock. It does mean that you pull it into the cut, but I've seen Ellsworth push it backwards, if you must push :)

This is a shear cut, a slicing, peeling cut and not a scrape. If you can imagine the angle of the bevel edge on the side wing of the gouge, it is very close to the same angle of a skew (depending on the type of flute on the gouge). I use this a lot to make finish cuts. The shear scrape works also, but the finish is not as good. The only difference is that the bevel is rubbing for the shear cut, and with the shear scrape the flute is pointing back at the work surface and the trailing edge is kept a bit above the cutting surface while the leading edge is scraping.

Otherwise, you and I do things a lot alike in the way we approach bowls.

[Dan Forman]

I pretty much learned to turn bowls from the first Bill Grumbine video. In it, he teaches four different cuts, three for getting out tearout resulting from the first cut, including a high shear cut and shear scrape using the long wings of the gouge. I have had to use all of those cut on nearly every bowl in the two or three years I've been turning, until now. The results from the push cut were a revelation to me. I'm sure that it's not the "only way" to do things, and that others can get good results with other methods, but for now I'll be looking for a method of work that allows the greatest use of this cut, which will eventually lead to a lot less time "cleaning up".

Here is a comparison of pull and push cut on the same bowl, same section, as can be seen by the arrow on the tenon. Granted it was a basic roughing cut, and I could have improved on it with a series of cuts with greater finesse, but the push cut was a basic roughing cut too, and I think the photos will bear out my enthusiasm for this approach.

The colors are different because I forgot to correct the white balance on the second one. The wood is soft maple that was about 75% dry.

http://i98.photobucket.com/albums/l279/T-Caster/DSC_0971.jpg

http://i98.photobucket.com/albums/l279/T-Caster/DSC_0972.jpg

Dan

[Jeffrey J Smith]

I've been solving this problem another way, and I hesitate to share this because it may sound unsafe, but I've never even come close to losing a piece yet.

I'm too lazy to set up the vacuum chuck just for this operation, so ...On warped rough outs, I just mount the warped tenon in the chuck - I use smooth dovetail jaws that are pretty large and leave a large tenon on the blank. As long as the tenon seats relatively cleanly, it always holds well in spite of being warped. The tenon seems to warp less than the rest of the blank (maybe I've just been lucky). Once secure, and with minimal speed, I true the rim and generally turn away just enough beyond the face of the rim (often less than 1/16th inch) just to see if there's going to be enough bowl left to deal with once the warp is removed. Then I turn a recess about 1/8th or less deep as large as my largest jaws will hold securely - usually about 5" or a little larger inside the blank.

Then turn the blank around, expand the jaws to hold the piece while the outside is finish turned and the tenon trued up. The jaws in expansion mode hold very well. It helps to use a chuck that can use a 10mm allen wrench to tighten as space can get tight in deeper bowls, but I've come up with a solution that even works with a OneWay chuck when necessary. It helps to use tower jaws if you've got them, but not absolutely necessary. Once it's securely mounted via the recess, and the bulk of the warped outside is close to true, I seldom bother with the tailstock. you can get a clean shot all the way from tenon to rim easily, pushing all the way. Like Reed, I turn at the end of the lathe with the headstock slid to the end. The push cut from tenon to rim is relatively simple this way.

With the outside done with the exception of finalizing the foot, turn it around, mount the tenon in the chuck and hollow the inside, then I'll break out the vacuum chuck to finish the bottom. Actually, if there are other pieces to finish, I'll wait to finish the foot area on all of them so I only need to setup for vacuum chucking once.

Takes longer to write this than it does to do it.

[Reed Gray]

If you watch Mike Mahoney and Stuart Batty do their '2 ways to turn a bowl' Stu does the push cut, and Mike does the pull cut. When done, you can't tell which one did which parts of the bowl, and I checked VERY closely. I did go out to the shop today and reground one of my Thompson 5/8 inch V gouges to a 40/40 grind, and didn't like it. Went back to a 45/40, and liked it better. I can get a number of different grinds to do pretty much the same quality of cuts, but always like to go to a heavy swept back scraper for a shear cut clean up. Kind of like Jimmy Clewes says, he doesn't like a burnished surface for sanding. I have been pondering that one for a while. Seems to make a lot of sense.

robo hippy

[Dan Forman]

Jeff --- I was talking to Hayes Rutherford the other day, and he does the recess on the inside same as you.

Well, I've got lots of ideas to play around with , so thanks to all who have contributed. I'll update after I've had a chance to try some. Right now, I'm still doing roughouts just to practice the cut and get consistent at it.

Dan

[Hayes Rutherford]

Dan, If Richard Raffan did it, I tried to do it. I'm sure thats what got me started remounting bowls using a recess on the inside. That being said, I don't always do it. RR also said the easiest way to get flowing curves was to point the gouge in the direction you are cutting. Another thing I try to remember is the cleanest cut is achieved when the cutting edge is about 45 deg. to the wood and that can be accomplished with a shallow gouge with the flute rolled over at about 45 deg. or a deep fluted gouge with the flute straight up or probably a shovel, skew or axe if the cutting edge is presented right.

A shallow gouge cutting toward the foot sometimes works fine or a negative rake scraper, then turn around and push cut toward the rim.

If you are like me about now I feel similar to the musician who was asked if he knew the theory behind the music he was performing and his reply was "not enough to hurt my playing"

[Stuart Batty]

Push Cut has been used in Europe for centuries. My father Allan Batty and my grandfather both used this technique. In fact there are no cuts in spindle turning that are not Push Cut. Push Cut is the best way to hollow a side grain bowl. Mike Mahoney and myself turn the center of the bowl out using the identical 40/40 bowl gouge and a 60/85 grind for the last third of the inside of the bowl and only push cut. However, we do not hold the handle in the same way. Mike holds the handle further forward and braces it under his arm. This does require more strength because it does not use the 5:1 overhang ratio rule. I prefer to use longer handles and only hold the back of the handle with my hand but with no bracing. This uses leverage and no strength and ensures to use a minimum of 5:1 leverage overhang ratio.

When it comes to the outside of the bowl there is the option to Pull Cut like Mike Mahoney or Push Cut like I do. Hence this is why I named to the two techniques to distinguish between Mike’s style and my style of turning.

When finishing a rough turned bowl using a tailstock for support it will interfere with the path of the handle for most but not all shapes. I’ll write an article on how to overcome this problem next week and post it with photos and text etc.

The upside of using Pull Cut for the outside of the bowl is that the tailstock/headstock or chuck will not interfere with the path of the handle due to it being held very low and controlled by both the left and right hand. The downside to Pull Cut is that is cannot match the finish of Push Cut, even Mike Mahoney mentions this in all his demos.

Push Cut is a skill based technique and cannot be mastered overnight. There is a lot of misinformation regarding this technique resulting in many fallacies about the efficacy of Push Cut. I would like to shed some light on the Push Cut, which is by far the most effective of all techniques to remove wood on a lathe without torn grain. Pull Cut, and all the various ways to scrape should be used to complement Push Cut and rarely should be used a solitary techniques to remove wood on a lathe.

Push Cut is like playing the violin, when done correctly it is a beautiful technique. We have all heard a great violinist and a poor violinist; the difference is more than obvious. A violinist uses the bow in the same way we should use the gouge for Push Cut, it is a balance of timing, pressure, feedback and one other very important commonality, control of the bow with just one hand. Though Push & Pull Cut has both the right and left hand holding the gouge; the control is very different. Pull Cut requires control from both the right and left hand – Push Cut will fail if your left hand influences any of the control. Control of Push Cut technique is solely one handed or the hand holding the handles for those who turn left handed.

I’m now going to write a follow up to the above and for the first time, write the rules on how Push Cut works. I’ll post it later sometime tomorrow. In the meantime we have all heard the saying “Rub The Bevel” this is a very misleading statement used about Push Cut and if you do in fact rub the bevel and create a burnished finish you are doing Push Cut wrong. More tomorrow!

[Faust M. Ruggiero]

Sorry Dan,
I was out of town since Monday morning and just returned. If you are knocking bowls off your vacuum you do not have a strong enough connection. I don't want to talk you into my way of working but even a 1/3hp vacuum will hold a bowl strong enough to completely turn inside and out. I am guessing you are not using a large enough vacuum chuck. On a 12"bowl I use an 8" vacuum chuck. I have up to 12" for larger bowls. I do not turn a mechanical connection on the inside, I merely turn the area that will contact the chuck I expect to use. I don't work like this all the time but do it fairly often to trust it. I also have a 3/4 hp vacuum that helps a lot with porous wood.
faust

[paul vechart]

Wow...what a great thread! I am learning so much from all the different techniques discribed. Can't wait to read more comments...Thanks...

[Hayes Rutherford]

Stuart, great analogy to the violin bow .

[Mark Levitski]

I race sled dogs. There is great discussion, debate, and strong opinions by renowned and expert mushers on which gaits dogs should have for accomplishing results, i.e., getting from point A to point B in the fastest time. In 30 years of this, I have learned to stop listening to the experts, or at least to stop automatically buying into what they say (they must be right, huh?) and to rely on what my dogs tell me and what my results are. Cutting wood is starting to look a lot like that, with experts disagreeing and all sorts of taking sides by the more novice onlookers. Starts smelling a little funny, and goes beyond trying to help someone in their quest to become a better turner. Find what works for you by whatever means, but don't buy into anything as gospel. I have had pull cuts in soft maple look like Dan's second photo. So can Dan. Don't be too quick to judge, and try for yourself.

P.S.-- If making the least reverses helps you, then factor that into which method you use to get your roughout finished.

[Mark Levitski]

Re-reading this, I didn't mean it to be as caustic as it might sound (just a litlle bit :)).

My point is: Whether you push or pull, whether the handle is long or short, whether it is held level or down is mostly irrelevant. What
IS relevant is how the edge of your tool presents itself to the wood. If it is a skew chisel edge, the blunt traditional gouge, the wing of the "Irish" grind, or as Hayes said, the blade of your hand axe, it is the way it contacts the wood that determines for the most part what happens. Sounds simplistic, but it is what my experience tells me is more important than allowing one's attention to go to more peripheral things.

Does the wood know whether you are pulling or pushing the tool to achieve the cut? It only knows the steel edge tearing at it. We as woodturners get to decide how to put that edge to the wood.

[Reed Gray]

Mark,
I hope we all know that there is more than one way to skin a cat fish (the original saying). I am a scraper psycho, and will pit my scraper roughing skills against any other tools out there. Of course the surface left is rough, but it is a roughing cut. Not many agree. Lots of different methods work, and the most important thing is to get from log to bowl with no blow ups or orbital launchings.

Best quote I have heard so far about rubbing the bevel is, 'the bevel should rub the wood, but the wood shouldn't know it'. I heard it was from an old skew master, but which one I don't know. Not Alan Lacer cause I asked.

robo hippy

[Dan Forman]

I do the initial truing up of the tenon and truing and shaping of the outside of the bowl with the tailstock in place. You're right, you can't use a push cut on the lower third with the tailstock in the way. I then mount the bowl in the chuck and do the finish turning of the inside so the inside is complete. I then reverse it on to a vacuum chuck but leave the tailstock in place until I have removed the bulk of the tenon. I then turn on the vacuum, move the tailstock out of the way, and do the final finish turning of the outside and base. I take a light push cut up the bowl wall from the foot to the rim for my final surface, and then remove the center nub and clean up the base. I have not had a problem with the bowl shifting off center when making the push cut up the side wall, but that is why I leave the center nub until after it is complete, so I can re-center it if it does slip. It seems to me that the only times I have had a bowl shift off center was when I was cutting across the base towards center and trying to advance the tool too fast as it encountered the slower moving wood near the center. At those times the cutting pressure is at right angles to the turning axis of the workpiece. When doing a push cut from foot to the rim the tool pressure is mostly parallel to the turning axis and towards the chuck, so should not push the bowl off center.

I prefer to use a vacuum chuck that is small enough in diameter to enter the mouth of the bowl and seat on the bowl walls 1/3 to 1/2 of the way down. That extra support on the inside of the bowl walls really seems to make it easier to get a good surface on the outside.

The method I use is shown starting at about the 10 minute mark of this video: http://www.youtube.com/watch?v=DDnSG0N6Tog

Take care
Bob

Thanks for posting the video. I wasn't familiar with that type of vac chuck - mine are made of pvc pipe, and the largest one is only about 4". I looked up your video on making a vac chuck, and will make a few of that style to get the added support at the top of the bowl.

Dan

[Dan Forman]

Push Cut has been used in Europe for centuries. My father Allan Batty and my grandfather both used this technique. In fact there are no cuts in spindle turning that are not Push Cut. Push Cut is the best way to hollow a side grain bowl. Mike Mahoney and myself turn the center of the bowl out using the identical 40/40 bowl gouge and a 60/85 grind for the last third of the inside of the bowl and only push cut. However, we do not hold the handle in the same way. Mike holds the handle further forward and braces it under his arm. This does require more strength because it does not use the 5:1 overhang ratio rule. I prefer to use longer handles and only hold the back of the handle with my hand but with no bracing. This uses leverage and no strength and ensures to use a minimum of 5:1 leverage overhang ratio.

When it comes to the outside of the bowl there is the option to Pull Cut like Mike Mahoney or Push Cut like I do. Hence this is why I named to the two techniques to distinguish between Mike’s style and my style of turning.

When finishing a rough turned bowl using a tailstock for support it will interfere with the path of the handle for most but not all shapes. I’ll write an article on how to overcome this problem next week and post it with photos and text etc.

The upside of using Pull Cut for the outside of the bowl is that the tailstock/headstock or chuck will not interfere with the path of the handle due to it being held very low and controlled by both the left and right hand. The downside to Pull Cut is that is cannot match the finish of Push Cut, even Mike Mahoney mentions this in all his demos.

Push Cut is a skill based technique and cannot be mastered overnight. There is a lot of misinformation regarding this technique resulting in many fallacies about the efficacy of Push Cut. I would like to shed some light on the Push Cut, which is by far the most effective of all techniques to remove wood on a lathe without torn grain. Pull Cut, and all the various ways to scrape should be used to complement Push Cut and rarely should be used a solitary techniques to remove wood on a lathe.

Push Cut is like playing the violin, when done correctly it is a beautiful technique. We have all heard a great violinist and a poor violinist; the difference is more than obvious. A violinist uses the bow in the same way we should use the gouge for Push Cut, it is a balance of timing, pressure, feedback and one other very important commonality, control of the bow with just one hand. Though Push & Pull Cut has both the right and left hand holding the gouge; the control is very different. Pull Cut requires control from both the right and left hand – Push Cut will fail if your left hand influences any of the control. Control of Push Cut technique is solely one handed or the hand holding the handles for those who turn left handed.

I’m now going to write a follow up to the above and for the first time, write the rules on how Push Cut works. I’ll post it later sometime tomorrow. In the meantime we have all heard the saying “Rub The Bevel” this is a very misleading statement used about Push Cut and if you do in fact rub the bevel and create a burnished finish you are doing Push Cut wrong. More tomorrow!

Stuart --- Love the violin analogy. I find the instant feedback very helpful - I can feel and hear when the cut is going astray. When it's going well, it seems like it's happening all by itself, kind of magical. The tricky part is keeping it going - like you say, a balancing act. The magic is happening more often now, the more I practice, funny how things work that way. I'll be looking forward to any more of your contributions on the subject, and thanks for stopping by.

Dan

[Dan Forman]

Sorry Dan,
I was out of town since Monday morning and just returned. If you are knocking bowls off your vacuum you do not have a strong enough connection. I don't want to talk you into my way of working but even a 1/3hp vacuum will hold a bowl strong enough to completely turn inside and out. I am guessing you are not using a large enough vacuum chuck. On a 12"bowl I use an 8" vacuum chuck. I have up to 12" for larger bowls. I do not turn a mechanical connection on the inside, I merely turn the area that will contact the chuck I expect to use. I don't work like this all the time but do it fairly often to trust it. I also have a 3/4 hp vacuum that helps a lot with porous wood.
faust

Faust --- My biggest vac chuck is only about 4" wide, made of PVC pipe. I'll be making some larger ones like Bob Hamilton shows in his video, should boost the holding power considerably, as well as help stabilize the bowl. I haven't really launched one, but did knock one off center once, so long ago I can't remember the circumstances. I've really mostly used it for turning off the tenon.

Dan

Dan

[Faust M. Ruggiero]

Dan,
The great thing about being a hobbyist turner is being able to spend time experimenting and learning how many ways there are to skin a cat. Every wood is different and may require a different technique. You can do an equally good job with a chuck as with a vacuum and you can surely do as good a job with a pull cut as with a push cut. Have fun and experiment till you have a mastery of as many cuts and tool positions as you can.
If you need any thoughts on how to make your own vacuum chucks let me know.
faust

[Dan Forman]

If you watch Mike Mahoney and Stuart Batty do their '2 ways to turn a bowl' Stu does the push cut, and Mike does the pull cut. When done, you can't tell which one did which parts of the bowl, and I checked VERY closely. I did go out to the shop today and reground one of my Thompson 5/8 inch V gouges to a 40/40 grind, and didn't like it. Went back to a 45/40, and liked it better. I can get a number of different grinds to do pretty much the same quality of cuts, but always like to go to a heavy swept back scraper for a shear cut clean up. Kind of like Jimmy Clewes says, he doesn't like a burnished surface for sanding. I have been pondering that one for a while. Seems to make a lot of sense. robo hippy

Reed --- Different strokes and all that, but I get a cleaner surface with the gouge than with a scraper, but I don't think it's burnished, because if you push the gouge into the wood with your left hand, which is the natural tendency, it all goes to heck. I think it's more like using a hand plane, which leaves a very smooth surface, but doesn't burnish. There is something about the physics about how the edge is presented to the wood that is responsible for the clean cut. I find it hard to maintain the alignment in the sweet spot over the course of the entire pass, so there may be ridges or dips when things go out of alignment, but with practice it's getting better.

I'm going to try using the fluteless gouge with a longer handle. I find it hard to control, jumpy early in the cut, I think in part due to its blunt bevel, and then it seems to go deeper than I expect when it get into the transition area, self feeding as it were. I have had the best luck with it working outward from the center at a shear angle an rubbing the bevel on the top of the bowl, that is, above the center line. Something about the shape and lack of flute that makes it hard to see what the bevel is doing while in use.

Scraper psycho? now you are scaring me!!! :)

Dan

[Reed Gray]

Dan,
If you watch my You Tube clip where I turn a bowl with nothing but a scraper, you can see what I am talking about. Agreed that a gouge will leave a cleaner surface, but mine still tends to wobble and leave tool marks which have to be sanded out, or I use a big heavy scraper to shear cut (no bevel rub, but that can be done) the get the marks out.

The fluteless gouge is difficult to start a cut with from an edge, same as if you try to start a cut with a skew on the end of a cylinder, rather than cutting from the middle and pushing the cut off the end. I think the thing with the bevel is not 'seeing' what it is doing, but 'feeling' what it is doing. The Dave Hout version was called a 'bowl skew'. When you are doing a bevel rubbing cut, like Stuart says, the left hand really does nothing other than rest on top of the tool. All the push comes from the handle hand. If you are doing a pull cut like Mike does, or a shear scrape cut with gouge or scraper, then both hands move the tool. I think the hand plane rubs on the sole, but the cutting edge is doing more of a shear scrape type cut, so there is no burnishing. I can fake it with a hand plane, but don't really know how to use them, so may be wrong here. Probably better with a skew than a hand plane, and that is scary.

Near as I can tell, the higher the shear angle, the cleaner the cut. However, as the shear angle approaches 70 to 80 degrees, it is more difficult to control/keep smooth and not bumpy.

robo hippy

[Dan Forman]

Mark --- My interest in the push cut is not driven by mystique, but by reslults, which for me are much better than I have experienced in the past with pull cuts. I believe there must be a reason for this, (other than mojo) and I suspect it has to do with the physics of how the edge is presented to the wood. It seems to take end grain factors out of the equation in ways that a pull cut doesn't, at least in my experience.

Dan

[robert baccus]

This is one case in which the "expert" is totally right. Me or Stewart---take your choice. He might even be better than me, who knows. He certainly agrees with all the experts I know and expresses it very well. Old Forester