Black Ash Burl with Natural Flaws

[Cory Norgart]

This is my first turning with natural flaws. Natural flaws have always caught my eye. I was a little skiddish starting this peice due to all the voids and concerns of constant catching. Now that I have tried it, I am trying to conquer a hollow form in such a way. Does anyone else have any pictures of hollow forms with natural flaws for our veiwing pleasure. This peice was presented to the mayor of our town in recognition to our new chapter in the area, Rainy River Area Woodworkers, the AAW's newest chapter. But, my main concern is a few tool lines on the bottom inside. I used a round, or, radius scraper to finish, but had problems with catching due to the inclusions. Suggestions?

 

[Steve Worcester]

If it can be remounted true, you could try a round nose scraper reground to a sheer scraper. Grind it to a 45 degree angle on each side like this ==>
The burr is on the top side, or at least the opposite of the side you just ground. The burr only lasts a little bit, so it is the type of tool that that requires a lot of resharpening. But a light touch, using the tool flat will take gently wisps of wood off the form. Not for radical reshaping

 

[Mark Levitski]

Cory,

I will answer you on this forum too. That is a nice piece of burl. Inclusions are a lot easier to cut if they are not loose at all. Sometimes you need to glue them so they are stabile for your tools to cut through without them moving and causing a catch. Sometimes there will be a peninsula-like flap that is the culprit. You will never get a good cut over that latitude of the piece due to the tool bouncing from hitting that flap. Glue it enough to stop movement and your cut will be much better.



And like others said, sharp. After taking all the precautions, you still might need to resort to some sanding in areas that remain problematic. Just be careful with sanding. You can't just apply the 80 grit to the piece spinning on the lathe. The softer areas and bark inclusions will quickly become indentations if you're not careful. Power sand the hard spots and go around the softer ones, at least until you get up in the grits.



I took a quick photo of a piece that I finished but have not yet buffed. Cherry burl, 6 X 6", about 1/8" thick:

 

[craterdog]

I turn a lot of hollow forms out of manzanita burls, incorporating the cracks, holes and other features of the burl. I turn the outside as usual with a 5/8" bowl gouge and then smooth it out with a 1" square scraper. At this point, I examine the outside very carefully to find the areas that I think are going to be problems when I'm hollowing out the piece. I use CA glue extensively to solidify thin cracks. In many cases, there are large cracks that need to be filled to reinforce an area before it can be turned. I use sawdust and CA glue in most cases. I have containers with sawdust of various woods like padauk, wenge, bloodwood, maple, etc. so I have a lot of different colors available. I like to create a contrast between the burl and the color of the sawdust to add more interest to the piece.

I hollow out the piece using the Jamieson system with the laser attachment. If I'm not sure how stable the piece is, I'll wrap it in clear packaging tape to reinforce it during the turning process. Hope these ideas are of some help.
Tim Carter

 

[Jarred Hoffpauir]

Similar endeavors

Cory,
I have been working with some pieces lately and have been working with a similar issue. I have worked with my mentors in my local chapter and have done some reading to help gain the appropriate tool skills. I have not solved the issue through improved tool skill however I am still working on it and its improving on each piece. I thought I would share what I found helpful so please consider this more of a discussion about a similar endeavor rather then "advice".

First thing I found helpful was sheer scraping with a sharp tool. Next was using a scraper of appropriate size. I was using a small 1/2 inch scraper for most all jobs and found the need to buy a larger one. I went with ones from Penn State only because they are cheep and I could get several and put different radius edges on them. Finally have a clean surface on your tool rest which will not have even the smallest grove to catch the edge of your tool. All those things have led to great improvement in the inside hollowing of my bowls, vases, and boxes.

My final but of wisdom to pass along is from my Mentor "Les Dawson" in the Seattle Chapter. Basically he told me that when I am showing a piece at our club "show and tell" or posting pictures he told me to not be so critical of my own work. Just let people look at it and judge for themselves. I found it difficult to accept praise for what I did well, without talking about the things I didnt do well. It seemed to be an exercise in accepting praise.

*Edited for clarity, a few typing errors sure can make things confusing*

 

[KellyDunn]

Cory, some pieces of wood will not get a clean cut no matter what you do. I would use a termite tool for my final bottom cuts. If I got repeated tearout in a section I would put ca glue on the area to firm up the fibres then take another fine cut. And then sanding has to take care of the rest. I do both my tool work and sanding at the highest speed I feel comfortable with. That way both the tool and paper dont dive into voids. To many or large voids and the piece gets stationary sanded. I use five inch discs for the outside so have lots of room to be careful. Inside 3 inch or smaller. Or even sandpaper wrapped around a goblet buff. I do whatever it takes to get the job done and to be as safe as I can. My first shop boss had me hold up my hands. He told me to be able to count to ten at the end of each day.These type of burls are a bear to do but sure look great when finished.

 

[Thomas Stegall]

Steve's suggestion is what I would try first (if you can remount it safely in a vacuum chuck etc). Another approach would be to use a hunter tool on a 45 degree angle which will cut finely leaving a surface equal or better than a scraper. The only problem with using the hunter is that it normally does not work aswell for the bottom/end, but works great for cutting from the side. However, since you have a wide opening you could angle a hunter tool to use the side of it on the bottom of your vessel. When safely and securely mounted, a higher rpm will produce a smoother cut when you are cutting wood-air-wood-air, but both higher rpm's and cutting into voids increase risks so turn safely i.e. face shield, tail stock support whenever possible as long as possible, and avoid standing in line of fire if possible.

If you can't remount, then I would suggest using a 2 or 3 inch soft sanding disk like the ones you would buy at craft supplies or "the glove" sanding solutions. These work very well for sanding the inside bottom of a bowl when mounted in a foredom handpiece.

One other thing to consider as a new turner....patience. Take your time at the lathe and strive to get the surface free of any tool marks by developing good tool control. It is not always possible, but can be accomplished most of the time. Then exercise the same patience in your sanding before you starting applying finish to the piece.

 

[John Giem]

Cory,


My final but of wisdom to pass along is from my Mentor "Les Dawson" in the Seattle Chapter. Basically he told me that when I am showing a piece at our club "show and tell" or posting pictures he told me to not be so critical of my own work. Just let people look at it and judge for themselves. I found it difficult to accept praise for what I did well, without talking about the things I didnt do well. It seemed to be an exercise in accepting praise.

*Edited for clarity, a few typing errors sure can make things confusing*

Jarred, I tell the turners that I am coaching to not tell me or anyone else about any flaws or errors in the work. If I or someone else, does not see the flaw, then it doesn't exist. When giving your turning as a gift, it's 'value' will be decreased if you point out the flaws.
John Giem