end grain issues with black walnut

[Roger Chandler]

I am currently working on a black walnut hollow form. I cut the logs in March '09 and sealed the ends with Anchorseal. Today, I cut some of them into halves, and made some blanks on the bandsaw.

While turning, I have had a lot of end grain issues, like fuzzing and some tear out, and a good bit of the sap wood is a little punky. I have sharpened my gouges several times, and even tried going both ways with the direction of the cut, and it is better one way than the other, but it seems there is more fuzzing or tearout than I am used to.

I was wondering if this is a characteristic of the growth patterns in walnut. I have turned walnut several times in the past, and had to deal with some punky wood, and some of the same fuzzing issues on end grain, but not this bad.

Am I doing something wrong in my technique, or is this the nature of the walnut itself? The log pieces were cut to about 12-14 inches long, and have been stored outside my shop in the shade, elevated off the ground, on pressure treated runners supported by concrete blocks. 😕

 

[Odie]

Roger......

I have run into the same "fuzzing" issue with walnut that still has excess moisture content. I haven't found this to be anything that sharp tools can't overcome on fully dried walnut. Since you are cutting logs into bowl blanks, can I assume your wood may not be fully dried yet? If so, you shouldn't worry about this at this point.

ooc

 

[hockenbery]

I find that black walnut left that longer than a month loses the whiteness in the sap ring and the sap wood has begun to decompose. That said I have turned pieces from a walnut windfall that was lying on the ground for at least 5 years. The heartwood was fine the sapwood was in pretty bad shape.

If you are getting tear out you need to try other techniques.

generally lighter cuts result in less tear out than heavy ones.
If a push cut with a sharp tool is getting tear out,I'll try a pull cut, or a shear cut. Then a tiny 1/4 bowl gouge for a light finish cut.
a finish cut with a spindle gouge....... Grain direction is important and sometimes alternative methods cut the grain better. This is particularly true with figured woods where the grain undulates.

If the wood has gone punky I'll spray it with water. this swells and locks the fibers together an will reduce or eliminate tearout in mildly punky wood.
If the wood is too punky for water, I apply shellac with double the alcohol in the mix. this penetrates the wood and the shellac fills the little gaps between the fibers.

If none of these work I wouldn't waste any more time. Walnut makes nice firewood.

happy turning,
Al

 

[john lucas]

I've had some trouble with walnut sap wood fuzzing up. It's not tearout because you can sand it down to a high polish later. I think it may be the sap wood is so much softer at this stage of partial water loss that it doesn't cut cleanly and it seems to leave a little fuzzy area even when cut with really sharp tools.
I can usually shear scrape it off after I finish turning the rest of the outside. Apparently the wood had dried enough by then to let it cut cleanly.

 

[Roger Chandler]

info much appreciated

John, Al & Odie,

I really appreciate your input on this because I was not sure what was occurring, and now I do have a better idea. The wood does indeed have some moisture in it, and I wonder if now that I have begun a hollow form [about 9" wide and 5" deep] if I am going to have cracking issues.

I think this will turn out to be a lovely turning, and I plan to use a maple collar, and a lid with a finial. I want to ask you guys about the thickness of the wall. Should I leave it 1/4" thick or turn it to 1/8th?

I only have a Sorby Hollowmaster for hollowing, and it is the large goose neck one, so I know I am going to have trouble getting a consistent thickness on the upper part of the form, as it goes to an edge with a steep angle that looks similar to a flying saucer that curves away downward towards the center [foot]. Probably one of the worst for hollowing anyway.

 

[Mr. Don]

Walnut

My theory....if it's too wet to burn it, then I turn it!!!

 

[John Beaver]

Roger,

I turn a lot of walnut. I love the way it contrasts with other wood. I just finished a hollow form that I intended to dye, but the Walnut was so pretty I left it alone.

You have been given good information. One thing I like to do is put a couple coats of sanding sealer on and then do a final cut with a 1/4 or 3/8 gouge. The sanding sealer hardens up the fuzz enough to make it cut cleanly.

The other thing that has worked well for me is slow turning (100 rpm or so) with a hand held cabinet scraper. You can go both ways with this too and it usually works pretty well.

 

[Roger Chandler]

Need different Hollowing tool

I made the Black Walnut hollow form today.... turned out nice, only the walls are definitely too thick! My Sorby hollowmaster would not get me to the desired thickness ... approx. 1/4 inch. For one thing the cutter on the thing is about 1-1/4 inch long now, after several sharpenings and you need about half of that to secure the cutter onto the end of the main tool.

Does anyone think that a boring bar with an angled cutter on it is the way to go, or maybe something is better than that. I am a bit inexperienced in hollow forms as I have only done a couple over the last 2 years, but up till now the sorby HM did okay, not great, just okay.

I am all ears to those who are successful at this hollowing thing, and look forward to your expertise.... Thanks

 

[Roger Chandler]

Sanding sealer to harden fuzz

Roger,

I turn a lot of walnut. I love the way it contrasts with other wood. I just finished a hollow form that I intended to dye, but the Walnut was so pretty I left it alone.

You have been given good information. One thing I like to do is put a couple coats of sanding sealer on and then do a final cut with a 1/4 or 3/8 gouge. The sanding sealer hardens up the fuzz enough to make it cut cleanly.

The other thing that has worked well for me is slow turning (100 rpm or so) with a hand held cabinet scraper. You can go both ways with this too and it usually works pretty well.

Hi John,

It never occured to me to use sanding sealer and then do a final light cut. I could see that it would harden the fuzzies. I turned the entire first part of this piece today, and it is lovely. I only wish I could have gotten the walls thinner, but the tool I have is limited, so I am asking advice from posters about what they think is reasonably priced and works well.

I am still going to turn a lid [from cherry I think] with a finial, and this will be my first finial topped piece. I think it will be real nice, but the walls are just too thick to suit me, but maybe I can remedy that on my next hollow form.

I like the idea of a hand scraper. Do you use the gooseneck or the rectangular one? Seems like a burnished edge on a gooseneck might be the way to go?

 

[John Beaver]

I like the idea of a hand scraper. Do you use the gooseneck or the rectangular one? Seems like a burnished edge on a gooseneck might be the way to go?

I usually use a rectangular scraper on the outside and the gooseneck on the inside of a bowl. Sometimes I will use one with a slight convex curve and hold it at a steeper angle.

 

[robo hippy]

I have never been able to get a good clean finish cut on the inside end grain, on any wood with a gouge. Scrapers, no problem, better with a shear/45 degree cut, better yet with a carbide disc cutter. Walnut does tend to be coarser than some other woods.

robo hippy

 

[ALAN THOMAS]

hollowing tools

Hi Roger
I turn quite a few hollowforms and I have found that making my own tools is usually the best way to go. It doesn't have to be fancy just effective! Most of my hollowing tools are made from 3/8", 1/2" or 5/8" round bar depending on the size of hollowform. The cutting tips are made from the shanks of twist drills (pick drills that are ground from solid HSS bar), ground to a similar profile to the commercially available ones, then epoxied into the end or side of the bar at the desired angle. The benefits of using HSS drill bits is that you can choose exactly the size of cutter you need and also you can use up all those broken drills that we all have laying around. You can cut and bend the bar as you require and as long as you are sensible and follow the basic rules when making hollowforms all you need to do then is find a local friendly woodturner to make you a handle.😀
Alan

 

[john lucas]

Alan could you post a photo of one of your tools. sounds interesting. I remember before Soren Berger came out with his box hollowing tool someone (I think it was Mark StLeger) tried using round end mills attached to a bar. I've thought about drill bits but haven't tried them.
I don't think drill bits would solve the problems I've had. I have a spindle gouge with a 35 degree cutting angle and have also tried the Hunter tool which has about a 25 degree cutting angle and even my skew which is quite sharp. Nothing seems to clean up this fuzzy area. This only happens for me on the sap wood. I've tried shear scraping and everything else I can try. Once it's dry I can sand it away. It's more like raised grain from when you wet wood. It's not tearout.

 

[ALAN THOMAS]

hollowform tools

Hi John
Here are a trio of straight shank tools that I use.As you can see, the angles of the tips are different depending on where in the hollwoform I am. I do have some swan necked tools as well but they are currently out on loan to a friend (as in permanent, I think🙄).
One of the things that you can do if you make similar tools is to rotate the tip to 30/45deg in relation to the shaft thereby giving you a shear angle on the cutter. This may help to give a cleaner cut on softer areas of grain.The cutters themselves are ground with a similar profile to your normal full size scrapers and must be razor sharp to be fully effective. If you still get tear-out or fuzzy grain try soaking the area with a 30/70 mix of dewaxed shellac flakes and denatured alcohol (the higher number is the alcohol and mixed by volume not weight) but make sure that the area is fully dry before turning again.It may take several soakings to stiffen the fibres enough to cut cleanly ( you could also try increasing the rpm to reduce the resistance to the cut) and you also have to consider what you final finish is going to be.
Hope this helps
Alan

 

[Roger Chandler]

where do you buy your tips?

Hi John
Here are a trio of straight shank tools that I use.As you can see, the angles of the tips are different depending on where in the hollwoform I am. I do have some swan necked tools as well but they are currently out on loan to a friend (as in permanent, I think🙄).
One of the things that you can do if you make similar tools is to rotate the tip to 30/45deg in relation to the shaft thereby giving you a shear angle on the cutter. This may help to give a cleaner cut on softer areas of grain.The cutters themselves are ground with a similar profile to your normal full size scrapers and must be razor sharp to be fully effective. If you still get tear-out or fuzzy grain try soaking the area with a 30/70 mix of dewaxed shellac flakes and denatured alcohol (the higher number is the alcohol and mixed by volume not weight) but make sure that the area is fully dry before turning again.It may take several soakings to stiffen the fibres enough to cut cleanly ( you could also try increasing the rpm to reduce the resistance to the cut) and you also have to consider what you final finish is going to be.
Hope this helps
Alan

Alan,

We have a guy at our local woodturner's chapter who also does some machining work. I think he could fabricate something like is in your pictures, but would most likely need the cutter ends. Where do you buy those, or can drill bits simply be ground to correct profiles?

Also, if drill bits can be used, then what size is the best for the cutters?

 

[ALAN THOMAS]

cutter tips

Hi Roger
The cutter tips I make come from the shanks of ordinary twist drill bits you can pick up from your local diy store, just make sure they are ground from solid HSS. All I do is grind off the fluted part. This leaves you about 1 1/4 of HSS bar to play with and form the desired profile. The size of drills that I use is dependent on the size of the bar it is going into and the size of the hollowform.
A half inch bar for example would normally have a 3/16 cutter and a 5/8 bar anything up to a 5/16 cutter. Remember that the smaller the cutter the less resistance there is to the cut. These tools can remove material really fast and come with a free a learning curve, so be patient and practice on scrap wood first. If you make a swan-necked bar remember to keep the tip of the tool in line with the centreline of the shank otherwise it could twist out of your grip or so I'm told 😉
Alan

 

[Roger Chandler]

Hi Roger
The cutter tips I make come from the shanks of ordinary twist drill bits you can pick up from your local diy store, just make sure they are ground from solid HSS. All I do is grind off the fluted part. This leaves you about 1 1/4 of HSS bar to play with and form the desired profile. The size of drills that I use is dependent on the size of the bar it is going into and the size of the hollowform.
A half inch bar for example would normally have a 3/16 cutter and a 5/8 bar anything up to a 5/16 cutter. Remember that the smaller the cutter the less resistance there is to the cut. These tools can remove material really fast and come with a free a learning curve, so be patient and practice on scrap wood first. If you make a swan-necked bar remember to keep the tip of the tool in line with the centreline of the shank otherwise it could twist out of your grip or so I'm told 😉
Alan

Thanks Alan,

That twisting out of your hand thing is something I have had happen already with the sorby Hollowmaster, and now I hold the handle near the shank with an underhand grip to support it against the downward motion of the rotating piece.

Your information is much appreciated! Thanks for taking the time to help a fellow turner that is less experienced in hollow forms 🙂

 

[Vernon Oberle]

tool bits

a couple of sources for tool bits are ENCO, MSC, and the Griz. Enco carries m2 steel tool bits at a very reasonable price and you get at least a couple out of each piece. You can get them in round or square. I have made a jig for the grinder platform that allows me to round the shaft to put in the tool. I also prefer to use medium super glue to put them in on the small bars and set screws on the larger bars making it easy to turn the bit around for reverse turning.

Vernon

 

[john lucas]

Alan The tools I build are similar. They are much closer to what John Jordan sells. I use 3/16 square HSS cutters. Other than that they are very similar. I think John uses a round HSS cutter in his. I thought maybe you were using the fluted section of the drill bit.

 

[Robert Manning]

I made these hollowing tools by following the design in David Ellsworth's book. He also sells these tools. They work extraordinarily well.

http://www.ellsworthstudios.com/david/books.html

 

[Roger Chandler]

Ellsworth tools

I made these hollowing tools by following the design in David Ellsworth's book. He also sells these tools. They work extraordinarily well.

http://www.ellsworthstudios.com/david/books.html

View attachment 3743

Hi Robert,

Thanks for these pictures and the information about David Ellsworth's book and the fact he sells them.

Our local club actually has him to do a 2 day demo and instruction on May 25-26th and I am looking forward to it very much. I guess we will learn some good technique for sure, and for sure I can really use it, 😀 as I am fairly new to turning hollowforms.

If I had a little instruction, and new tools [at least that is what I am telling myself to justify the purchase 😀] I think my skills in this area may just get elevated to a higher level real soon.

I appreciate your response... this info is helpful to me 🙂

 

[ALAN THOMAS]

hollwing tools

John,sorry for any confusion about what part of the drill bits I use. I think that most of us use the same kind of design for our tools, it's just the materials that may differ.
Robert, the tools that you made look far too professional for me!🙂 The only reservation I have is about the tool with the crank in the shaft. That has to give your wrist a serious workout!

 

[Robert Manning]

Robert, the tools that you made look far too professional for me!🙂 The only reservation I have is about the tool with the crank in the shaft. That has to give your wrist a serious workout!

Thank you, Alan, I find the cranked shaft tool to be comfortable to use. You do need large handles on these tools and a sighting mark on the front of the tool as Mr. Ellsworth mentions in his book. My photo is just a small sampling of the various tools I have made.

Alan, the advantage of the 3/16" square tool bit, is the super high speed steels that are available. I am using 5% and 10% cobalt bits and there are M34, M43, and T15 available at reasonable cost. I often use my largest four foot straight tool for ripping off bark to rough-out a blank since the steel bit is long lasting and replaceable.

 

[ALAN THOMAS]

Alan, the advantage of the 3/16" square tool bit, is the super high speed steels that are available. I am using 5% and 10% cobalt bits and there are M34, M43, and T15 available at reasonable cost. I often use my largest four foot straight tool for ripping off bark to rough-out a blank since the steel bit is long lasting and replaceable.

[/QUOTE]

Hi Robert
When I get asked to teach the making of hollowforms most students as me how to make the tools the cheapest way they can. Using HSS drill shanks is an easy option for most people and they are easily aquired from local diy outlets or they have them in their workshop. When I first started making these pieces 15 years ago there wasn't a lot of choice and I guess I have stuck to what I know.
To be honest I haven't tried any of the cobalt supported HSS steels in my hollowing tools but I have been thinking about trying them when I run out of drills.I will have to find a supplier and move into the 21st century🙂

 

[john lucas]

Alan That's why I use the 3/16" square HSS bits. I can buy them from Enco or other metal houses for as little as .75 each and they are 3" long. They are easy to score and break to a shorter length so you really get 2 or even 3 out of each cutter. Since I usually put them on with another order of metal or drill rod the shipping isn't a problem.