bowl gouge pivoting for roughing

[john lucas]

we discussed this the other day. I found this video and near the beginning he uses the pivoting method to get rid or wood on the out of round bowl. Most of his other techniques are fairly good however he mentions lines caused by the gouge and says that they are there because he didn't change the gouge presentation. they are actually there because he has a sharp corner on the heel of his gouge. That sharp corner bruises the wood. Lightly if your moving the gouge but if you stop or slow down it will bruise it to the point you can't sand it out. you won't see it until you get to the finer grits and it takes finish differently. I learned from Charles Alvis a long time ago to round over that bottom corner and it stops that.
https://www.youtube.com/watch?v=1K1BdwiJtmE

 

[Barry Crowder]

That's a pretty long video, john. I assume that you mean what he's saying at around 25 minute mark?

The point you make about the rear edge of the heel of the gouge is one that I don't see discussed on YouTube very much. It comes up regularly at my woodturning club, however...

 

[Jamie Straw]

I can totally see how the wood could get bruised (at 25min section)! I worry about that, even with the heel ground back as I do. Big question that comes to mind as I'm watching him cleaning up the outside (earlier in the video) is how he standing right where the bowl would go if it blew up or came off. Am I being too idealistic about staying out of the line of fire?

 

[Bill Boehme]

Looks like he had a little catch at about 13:55 ... It looked like he touched the tool to the wood before anchoring it on the tool rest. Anybody know what kind of lathe is he using, it sure seems to be noisy like my old Delta that had a Reeves drive?

Oak (especially white oak) almost always seems to have lots of flaws, but it is also a very beautiful wood.

Jamie, when the wood flies off the lathe it is generally due to something in addition the just the spinning force. Shearing at the tenon, a big catch, bouncing off the bed or tool rest after launch are just a few things that alter the trajectory. So, in reality the line-of-fire is more like a fan shaped pattern, but the greatest probability of launch is perpendicular to the spin axis.some things like the tool rest help deflect the wood away from you, but the best thing to do is avoid doing dumb things. I would guess that most launches are the result of turning crappy wood. Other things include lathe speed too high and not listening to the sound of the wood. The list goes on and on. Wear safety gear.

 

[john lucas]

Turning wood with checks, punky tenons, or catches are what throw bowls 99% of the time I'll bet. Long before I knew about the line of fire thing I always stood in the line of fire. I found that I could more accurately judge the shape of the bowl by watching the back profile while I turned. If I did that then I could control the gouge better while I made the cut. If I cut without watching the profile then I would have to go back and change that little area that is a little flat or a little out of round. So I still do that. I just don't do it if there is any sense that the bowl has a flaw. I do wear a face shield more often now, in the early years I never wore one. They gave me headaches. I'm slowly learning to get over that and wear the face shield more. I had a lot of bowl dismounts early on. Chased many a blank across the shop. Fortunately I never got hit. Whole blanks coming off seems to be less dangerous than blanks exploding from cracked wood. I did turn at a lot slower speeds in the early days. Maybe that's what saved my butt. Turners today buy bigger lathes with more horse power, watch Jimmy Clewes turning at warp speed and then think they can do that. Of course they don't have his skill and they often choose wood that already had cracks, just like that guy in the video. When I have a piece like the one he had in that video and was bound and determined to save it I would wrap stapping tape around the outside before continuing. Life is too short to take those kind of risks today.

 

[hockenbery]

When I turn blocks of wood into bowls and hollow forms I need to keep the bevel on the wood and see the shape develop.
Learning to turn with either hand forward has made that much easier to do.
I can position myself to see the form, control the tool, and not get hit by the chips. This also keeps me out of the line of fire for the most part.

Like bill said a block coming apart is usually more dangerous than a whole bowl coming off.
Proper mounts, appropriate speed, proper tool presentation, proper body position, good lines of sight greatly diminish risk.

Done properly on a lathe with a good tailstock, between centers is an excellent mount for roughing bowls and hollow forms. With centers griping solid wood, tight tailstock, block balanced for weight, and reasonable speed - between centers if very safe for roughing.
If a catch is made or too aggressive a cut slows the lathe the most common thing is for the spur drive to drill into the wood and the blank never comes off center.
If the wood is not so solid a center can pull out when the wood breaks and the bowl almost always falls down.

That said I know of one accident in which an unbalanced blank was mounted between centers on a lathe left on high speed. When the lathe quickly reached too high a speed the bowl came off and went up and came down striking a hand of a bystander causing considerable damage. How well the drive center was seated, how well the tailstock was locked, and the quality if the wood are unknown. In this case the line of fire was from the ceiling.

 

[John K Jordan]

Good face shields?

Turning wood with checks, punky tenons, or catches are what throw bowls 99% of the time I'll bet. ...
When I have a piece like the one he had in that video and was bound and determined to save it I would wrap stapping tape around the outside before continuing. Life is too short to take those kind of risks today.

I agree about the wood being the problem. I have had pieces come off and hit my hand when a "cool" feature of the wood gave away. The face shield and even standing out of the way won't help that! Besides that, I have never had a piece come off the lathe except for a small box blank before I learned how to control the tools, and that just dropped into my shavings tub.

Of course, there are risks with almost every activity other than sitting quietly in a darkened room - I was reminded about that just yesterday afternoon when my biggest horse decided to buck vigorously and remove me from the saddle following a TINY jump - probably because he was used to jumping with featherweight wisps of teen girls instead of the big old guy fat guy with twice the weight. I ended up slamming the ground with my chest from at least 6' up, pert near enough to knock the breath out of ya! One might think one would finally grow up and act one's age as one got closer to 70.... Nah.

I first saw the strapping tape method used by my buddy Paul Menchoffer, the potter, almost 40 years ago way before I started turning wood. He would turn big things full of voids with this method and never had one come apart.

Speaking of face shields, what is a good source of the type the demonstrators were using at the TAW? I'm still using the face shields I get at the welding supply store. I'd also like to find smaller face shields that would fit kids better, if such a thing exists.

JKJ

 

[john lucas]

John I hate face shields. However the Uvex face shields are both comfortable and you can actually see out of them without distortion.

I would like to add to Al's advice on tailstocks. I start almost all bowls between centers. That is very safe and this is where I'm observing the outline of the bowl. At this stage the bowl is thick and you can stop every so often and check for cracks and defects. Then you can either toss the piece or change the shape to cut them out. When I get to the dangerous stage I am hollowing and then of course I'm staying well out of the line of fire. At this stage I'm still looking for defects that will make the bowl unstable. If I find one I have to make a decision on whether to save it or not. It's at this stage that I might use the strapping tape or some other method to stabilize the bowl and keep me safe.

John since you can't seem to grow up I guess I'll just have to come down there and play. Mrs Jordan, can john come out and play.

 

[hockenbery]

Our club has safety reminders every meeting. Meeting before last was about fire prevention and the proper extinguishers to have in the studio/shop
Last meeting was about the safety of turning blanks.

John talked about what he does while turning. I'm sure he studies the wood before he cuts it and after it is cut and may reject it then.
When chainsawing or being given wood I inspect the bark surface. The cut surfaces..

Cracks and splits: I usually discard these. The splits may grow under the forces of turning creating two pieces of wood.
Plus I will have a crack in my finished piece.

Bark inclusions: Abnormal bark tells me to look for defects. The most common I encounter is crotch wood bark inclusion. A sort of stitching or raised bark along vee of the crotch usually means bark inclusion. Bark is not a structural component of wood. I never use a blank that has a bark inclusion running completely through it.
It may hold on the lathe and as soon as I cut through whatever solid wood is there you have two pieces one flying and the other maybe still on the lathe.
A bark inclusion in the rim, or side wall of a bowl or hollow form is usually not problem. However be aware deep hidden inclusions sometimes occur.

ring shakes/ wind shakes: these are separations around the growth rings. Sometimes hard to see. The wood is not physically attached across the growth ring.
Because the inner part is enclosed in outer part they often hold together. On the lathe when cut enough away they come apart. The onion burl thread had examples.
I have found that black walnut seems to have more ring shakes than other species.

Pitch pockets - these are sort of like bark inclusions but maybe some long ago damage to the tree created a space inside the wood that fils with pitch.
Lots of small ones make terrific patterns. One large one makes a bowl in two pieces. Cherry sometime has these as well as some of the tropical storm.

Rotten wood : I like to turn wood that has hollows, healed limb scars, and spalting.
These blanks often have rotten areas. Obviously if the wood crumbles in your hand it is not going to hold on the lathe. It is the wood that seems okay that we need to be carful with. I use a screw driver test on spalted wood. If I can push a dull flat screwdriver into the wood more than an 1/8 of an inch with little force, I don't turn it.

Black stains in the wood often indicate hidden metal.

When I'm turning I inspect the surface periodically to see how well I am cutting and to spot any structural concerns. I also listen. A ticking sound usually indicates a hidden crack.

In the end we all make decision about what we as individuals feel is safe to turn.
We all need to work within our limits. For Maoist of us this limits expand with experience.

 

[robo hippy]

Well, standing out of the line of fire is a big part of safety. If you saw my Using the Big Ugly clip, you saw me launch one, and my camera man as been trained to stand out of the line of fire also.

Having the heel ground away on your inside bowl gouges is huge in not getting any circles and bruises. I was having that problem with one BOB tool with a 70 degree bevel. I reduced the bevel to about 1/16 inch, and rounded over all the rest of it to a 1/4 round radius, so no flat spots or sharp heel to dig in. Made all the difference. This is essential for any convex shape.

robo hippy

 

[John K Jordan]

John since you can't seem to grow up I guess I'll just have to come down there and play.

When you come visit, our Lovely Brides can go play at the antique stores, a day trip to the smokys, rodeo practice... whatever makes them happy. Sharon has been riding one of the horses a lot - we had a good laugh (which hurt a lot with bruised ribs!) the day I took the flying belly flop into the dirt - she came off her horse a few weeks ago and bruised a rib enough to make even getting in and out of bed difficult. When I saw the doctor yesterday about my twisted knee he was somewhere between "so glad to see you two are staying active" and "are you Crazy?!" Ha!

I'm leaving on the 19th for a trip but before or after that the Jordan Farm Bed and Breakfast is open for business. The cost is high, though: some good conversation and some exchange of creative ideas!

JKJ

 

[Jamie Straw]

When you come visit, our Lovely Brides can go play at the antique stores, a day trip to the smokys, rodeo practice... whatever makes them happy. Sharon has been riding one of the horses a lot - we had a good laugh (which hurt a lot with bruised ribs!) the day I took the flying belly flop into the dirt - she came off her horse a few weeks ago and bruised a rib enough to make even getting in and out of bed difficult. When I saw the doctor yesterday about my twisted knee he was somewhere between "so glad to see you two are staying active" and "are you Crazy?!" Ha!

I'm leaving on the 19th for a trip but before or after that the Jordan Farm Bed and Breakfast is open for business. The cost is high, though: some good conversation and some exchange of creative ideas!

JKJ

My GP was never so happy as the day I told her I'd stopped training horses. She didn't enjoy reading the reports from the Level I trauma center and their surgeons.😛

 

[hockenbery]

I put a 4 minute video clip on YouTube from a demo I did a few years ago on gouges.
I have found this method for initial roughing to be easy on the body, efficient, and clean cutting.
I start all the larger bowls and hollow forms this way .

The video shows a blank on a screw center and the first roughing cuts where I cut a cove on the corner.
It also show the "A" frame stance where I just pivot my body to cut.
This stance keeps the gouge from going over the tool rest when it is cutting air so that it continues to cut without bouncing.

Initial roughing cut
http://www.youtube.com/watch?v=EIHADKjfL2c

This 3 minute video of the turning out the outside of a 12x8 inch natural edge bowl blank is a good follow on to the first.
It starts right after the first cove is cut and end with a finished outside.
http://www.youtube.com/watch?v=qZ0fC5Rk6h4

 

[Barry Crowder]

Another video on the subject of roughing a bowl, by Brian Havens:
https://www.youtube.com/watch?v=lexrdkV_cG8

In a follow up video, he mentioned switching to doing this left handed:
https://www.youtube.com/watch?v=C-9BW1v2NWU
I followed this suggestion (left handed) today while roughing some bowl blanks, with good results. It was only a little bit awkward, at first.

 

[robo hippy]

All of those 'roughing' cuts, and they all do some thing I don't do, and no, it isn't using scrapers instead of gouges. I always start as near to the center as I can when roughing. One reason is the wood is moving slower, so if I accidentally stick the cutting tool in without paying attention, the accident is very small. Also, by working my way out from the center, I always have a flat and even surface or platform to start from. I tried to start on the rim, which is generally the most uneven place, and it is more stressful on your body.

My version on a nice piece of sycamore or London plane tree:

https://www.youtube.com/watch?v=mN2bKMQFuFk

robo hippy

 

[hockenbery]

Reed, Nice clear video, Anything you can do to reduce stress on the body parts is a good idea.

That is why I use the A frame roughing cut with the Ellsworth ground gouge.
No stress on the body and gets rid of the uneven part first so the speed can be increased to make the rest of the roughing easier.
Once the corners are round I like to work from smooth to rough much like you do it makes forming the curve easier.
For me this is so much faster and less stress than scraping, but you are much better with scrapers than I am.

I think scrapers require working from smooth to rough more than the gouges.
A gouge can make a really clean cut on a rough irregular surface. I have never had any success making a smooth scrape on an irregular uneven surface.

I can use an Al Stirt style scraper nicely to smooth the interrupted surface on the corners square edge platter or bowl.
I would not use a scraper to surface the square edge.
The side ground gouge does it so well and easily.

 

[robo hippy]

The trick to reducing impact is learning how much you can bite off at one time... Same with gouges or scrapers. Keeping the tool rest close to the work is a big part of this, and why I use inside and outside bowl rests.

robo hippy

 

[hockenbery]

The trick to reducing impact is learning how much you can bite off at one time... Same with gouges or scrapers. Keeping the tool rest close to the work is a big part of this, and why I use inside and outside bowl rests. robo hippy

I agree that with scrapers I want the tool rest close although when using them at an angle for shear scraping I can be over the rest a lot further.
Gouges I can cut with nicely over the rest 4-6" depending on the wood. Of course the further over the rest the lighter the cut and the poorer the surface.

i like the Robust "J" rest for working inside larger bowls.

Last week I demoed a 8" wide natural edge bowl on a lathe that only had a 4" wide rest.
It was fun! :-( not
In the bottom center I had to work about 7" off the tool rest.

I attached photos. Of the bottom center of two bowls.
The one with the tiny bump is the one I was working 7" off the rest. You can see lots of tool marks and I decided to leave the small bump because I thought I was about 50/50 on digging a hole. The bump will sand off with 220.
The other photo is a natural edge bowl about the same size where I had a longer rest that could go down inside the bowl fewer and smaller tools marks and fairly clean center cut.

 

[Jamie Straw]

[Snip]... I decided to leave the small bump because I thought I was about 50/50 on digging a hole. The bump will sand off with 220.
The other photo is a natural edge bowl about the same size where I had a longer rest that could go down inside the bowl fewer and smaller tools marks and fairly clean center cut.

What's your secret to sanding that almost-zeroMPH area? I have alot of trouble accomplishing removal of marks or small bumps there. IMHO, "fairly clean" is a bit of an understatement.😀

 

[john lucas]

I sand by hand with the grain in the middle of pieces where you don't have the surface feet running by. I simply turn off the lathe and hit it by hand. Same with torn grain areas.

 

[robo hippy]

I make sure to bring my own tool rests when I demo, chucks, tools, and grinder station. I don't like having to adapt. Still working on my inside bowl rest. The problem with the ones available now (Oneway, Robust) is that while the 1/4 or so arc section works, the vertical post is in the way.

For getting the center nib out, sweeping shear scraper, and power sanding.

robo hippy

 

[hockenbery]

I sand the natural edge bowls and hollow forms off the lathe when they are dry a few days after turning.
I use Velcro discs on padded mandrel so
Stiff pads on the outside and softer ones inside. It try to use the edge of the disc and keep it running with the grain lines

If I'm sand on the lathe I stop the lathe to work the center of the bowl.
Like John any area that needed special attention I would sand with the lathe not running.
Easier to take a little off one spot by staying over it than it is to take the whole surface down to fix one spot one spot.
Just be sure to blend the spot in so it doesn't look like a hole and sand the whole surface with the lathe on to blend it in more.