Wood turning question

[Woodbutcher]

Hi, I'm new to this forum and the computer too. Thought this might be a good place to get some good advice.

I am turning poplar. My detail keeps breaking off. Could this be due to low moisture content in the wood? I have always used poplar in the past for paint grade ballisters and never had problems turning details in them. The current project contains lots of beads and at the point of just getting the bead ready to sand, it just comes off in pieces. The wood is old as far as being premilled several years ago for it is coming out of a large inventory. I do not have a moisture meter but a good educated guess would put the moisture content down around 2-3%. I am even using a new Sorby beading tool. Any feedback would be helpful.

Matt

 

[Steve Worcester]

Higher moisture would lead you to believe that you would have more flexibility and the feature wouldn't break off, but I don't think that is the problem.

You don't say what the diameter is, but it could be it is just too thin and the beader is flexing it too much, maybe you are using too much pressure on the beading tool?

 

[Woodbutcher]

I am trying to make 1/4 inch beads on a spindle with a diameter of 1 3/4 inch . The spindles vary in length 10 inch to 29 inch , all solid stock clear and free of defect ;checking, knot ,mineral steaks & was resquared with sizable stock removal . My lathe although an antique is in excellent condition ,I am 48 and have been turnning scince I was 12 . I have been doing historical turning in the Northeastern U.S. scince mid 80's , allthouh you may have a point when you refer to pressure. I am extremely profficient with hand planes, and chisels .

Thank you for the input into my problem

 

[Ken Grunke]

You have much more experience than I, and maybe even most of us here so don't know if I can offer any help but I'll try.
Possibly the use of a beading tool is the problem--it's making a scraping cut, where a shearing cut would be more advisable. How are you with the skew?
A skew with a razor sharp edge, honed and polished, will lessen the chance of chipping. To polish an edge, I use white buffing compound--the stuff intended for stainless steel. I have an MDF wheel mounted in a little tabletop drillpress for this, or you can rub the stuff on a piece of cerealbox cardboard and use it like a strop.

Another thought is using a cutting lubricant, usually for bowls to help prevent tearout. Sanding sealer, paste wax, thinned varnish, even water has been used. Just glob it on and turn right away. Not sure why it works, but it may help in your case. I have turned quantities of poplar spindles, and did have chipping problems--mostly when entering a cut on a square. I didn't know about cutting lubricants at the time, all I could do was keep the skew sharp as possible and go slower on the entry cut.

Maybe soaking the wood in water a few hours will help?

 

[MichaelMouse]

I'm assuming tulip-poplar rather than true poplar. True would be a lot more forgiving.

You're too dry, no doubt. Makes the wood brittle, and you can crush or break it with very little pressure. Age of the stock, especially in the number of seasonal cycles, can also make a difference. There's a bit of compression set introduced every dry season. This wood is better used as flat stock.

Though I don't see it in your post, a scraping "beading tool" would certainly crumble the wood easily. If you have what is traditionally referred to a a beading tool, a straight chisel-type cutting tool, your rate of success would be higher, but I don't think you're likely to get it high enough to make money.

Scraping is pretty easy to recognize by ear or sight. If you're using a scraping action, regardless the tool, you'll hear it, and you'll see it in the form of dust production and light scatter from the surface you create. If you're silent and slick and still get the crumbling, use the wood for cabinetmaking, it's too old and brittle for good turning.

 

[Woodbutcher]

I would really like to thank all of you for your time to respond .

The tool is ;Robert Sorby #835H 1/4'' bead forming tool
which i would refer to as a scraper

The wood I beleve to be poplar, but now we get into regional advailability
which I have always found an effect, Clear white wood , excellent stabillity,
medium density ,close grain, My most common use is paint grade millwork, moulding ,paneling, beadboard, ballisters, knewels, and interior doors. Along
with interior framing in casework.

The lot I am currently using is on my own home, of which about 65% of my woodwork is poplar. About 75% of my stock is white ,the rest has some color,
light green , light tan , streaks of purple, it does age to light yellow tan . The
gentlemen whom I have been gifted to work under always referred to it as "
White wood "

On the subject of lubricant, you mentioned water, could I just wet the area to be formed? For poplar does soak up moisture rapidly. Or would I have to soak the blocks for a day or two like you suggested? With sanding sealer, once again would I be able to apply this in the problem area? I would be using hydrocoat's water based sanding sealer for I am trying to get away from nitro cellulose laquers. At this time I don't have a digital camera. The bead details are extremely congested, coming off of squares. They are for a gate leg assembly at the end of a kitchen pennisula and then there are some turnings for support braces for a counter behind the same pennisula.

I am overwhelmed by the responses and once again thank you, regardless of experience. One can always learn from another.

 

[Woodbutcher]

I would like to thank ;Steve Worcester, Kengrunke, and Michael Mouse for
thier feedback and insight. I have managed to complete my project using suggestions made . Woodworking is a learning curve, and one thing I learned
a long time ago was never be close minded to others' suggestions. I enjoy
logging on to this site and reading the discussions, and viewing the gallery.
The pieces in the gallery are fantastic. I am sure you will hear from Me in the
future, Thank you once again.