Wet Bowl turning problem

[Thom Sturgill]

Grumbine's DVDs are great. I also suggest Mike Mahoney's Bowl Basics video. It has the best info on creating a tenon that I've seen. He also discusses tool grinds as he uses a different grind than most.

[Michael E. Thompson]

Rob, I agree with Scott that your problem likely is tool position. Me personally, on a bowl that size I would use a smaller bowl gouge more like 1/2". Nothing wrong with using a 5/8", just seems to be a bit overkill to me. You can take a lot of wood off with a tool that size. What kind of grind are you using on the gouge? If its a swept back grind, you may be using the long edge to make all your roughing cuts. That is a lot of cutting area against the bowl. Catches can easily happen. You will see in the videos Bill will have you present the tool with more of the tip rather than the side, as well as "rubbing the bevel". Keep in mind you are not actually cutting with the tip, but right next to it. The video will describe tool presentation much better than I can.

The other thing I noticed from the picture is your tenon is a bit cone shaped. Make sure the tenon has the same profile of the jaws on the chuck. Its hard to tell on the chuck, but it looks like it has a dovetail shape. The chuck will hold the bowl very well with the correct profile, and as other have said, shorter tenon.

Just my opinion.

Hope I didn't confuse you. You will enjoy the videos, I learned a lot from them.

Mike

[GLENN THOMAS]

Rob,

Looks like you got some good advise from everyone. On thing I noticed and it was hard to tell from the picture but it looks like the bottom of you bowl curved right into the tenon. In addition to cutting you tenon in a dove tail you should also leave a small portion on the bowl bottom flat where it intersects the tenon. The angle between the tenon and the bottom of the bowl should be 90 degrees and this flat area only needs to a half inch at most. This will allow the bottom of the bowl to sit squarely on the end of the jaws and that makes it a little harder to knock the bowl out of the chuck. For me it is very difficult to explain in words how to present the cutting edge of a tool to a piece of wood. There is a very fine line between having you flute too far either way, there is a very small sweet spot. The video you ordered will be the next best thing to having some one show you what to do. In addition to Bill Grumbine videos I would also recommend watching Jimmy Clewes videos if you get the opportunity.

GT

[Richard Madison]

Rob, If your 5/8 BB gouge is like mine, it is a deep V. I found it very difficult to control (a few years ago) and never use it. As mentioned, use a smaller gouge if you have one, simply because it will be easier to control. It appears that you were indeed struggling with tool control/presentation and the Grumbine videos should be very helpful.

[Dennis Ford]

You have gotten lots of good advise, I hope this is also useful. Keep that bowl! It can most likely be salvaged after it drys and you have a little more experience. I would wrap it up in some brown paper and put it out of the way. It looks rough now but a "rough-out" does not have to look pretty.

[Mark Levitski]

Hi Rob. I agree, great advice, valuable forum.

Yes, salvage the roughout. Looks just like any other.

Your chuck is the same as one of mine and also the jaws. I have turned many bowls with tenons longer than 1/4 to 3/8" w/ no problems with these jaws. Just as was said, just don't let the tenon bottom out against the inside back of the jaws. If it broke leaving 3/8", I would think it was not from the leverage of a long tenon--the remaining shorter tenon should have held the piece. The key, as mentioned, is to keep a flat face for the jaws to seat against, as well as a slight dovetail to match those jaws (they do have a dovetail). For the tenon diameter, I would highly recommend leaving more than a 1/4" over the fully-closed jaw diameter when you do your roughouts. Only 1/4" would mean turning off only 1/8" off each side of the "ovalness", and in my experience, 'taint enough. (What do you others say re: this?) Most bigger bowls will go oval more than that when drying and you will have to resort to not only truing up the tenon but turning a smaller one for totally different jaws on the chuck, or doing a glue block--more work than necessary. Been there, done that, learned how to accomodate this. Did you true the tenon after the bowl dried?

Good luck and keep at it. Beyond all the advice, it mostly takes doing over and over.

[Thomas Canfield]

It sounds like there are multiple things going against you.

I agree that the tenon is too long and needs to be short enough to allow the back side to seat against the face of the chuck.

The tool marks on your "green" bowl look like your presentation of the cutting edge is not correct to rub the bevel or tool dull. What speed were you using? Higher speed will give you a smoother cut within reason but you still need to keep the speed within the normal turning speeds recommended. Unbalanced rough wood needs to start out slower until the removed wood improves balance and allows higher speed.

Shallow bowls or saucers are easier to work on at first. Trying to go deeper or steeper cuts are more prone to catches, especially trying to work the bottom.

Another vote for the Bill Grumbine dvds. I watched them and it helped me a lot. Today, I turned 6 green Bradford Pear bowls from 11" down to 8" diam, sap slinging all the while. Once you get the hang of it, the shavings seem to flow off effortless. I did notice that I had to sharpen (or change tools) during each exterior, but could do at least 3 interiors per tool. Sharp tools make the difference. It took about 15 - 20 minutes to turn the exterior and tenon, and 5 - 10 minutes to turn the interior. I use the screw in my Oneway Stronnghold chuck and had rounded up the blanks with bandsaw circle cutting jig and turned at about 650 rpm on my Powermatic 3520.

All that said, I will admit to having one catch on the exterior of one blank and twisted out the threads for the drive screw being too agressive. That blank will now have to be done with a faceplate tomorrow. There was a dry limb section on the green wood that really grabbed the heavy cut being done on the green wood.

[Maylon Harvey]

Rob,
Where in Western NY? How close are you to me?

[Rob Holcomb]

I want to thank everyone for their input and advise. Believe it or not, the Grumbine videos will be here tomorrow. I'll spend the weekend watching them and then put the teachings to work and practice practice practice! Maylon, it looks like we live 3 hours apart from one another. I'm in the Southwest corner of NY in Jamestown. Since there aren't any clubs or classes closer than 2 hours away, I'll have to stick to the videos and offerings by all of you. There's a Woodcraft in Buffalo that has classes from what I've been told and I plan on checking into the dates/times they are held. Unfortunately, work, wife, kids and my flat work makes it difficult to take off for a day but I think it would be in my best interest to make room in my schedule to do that.

[Bill Blasic]

Ron,
If you feel like traveling to the Erie PA area I'll fix you up with a lesson. We have a member or two from Jamestown in our club the Presque Isle Woodturners.
Bill

[Rich Aldrich]

I agree that getting some lessons really helps. Steve Schlumpf showed me how to rough out a bowl. His help was excellent. I have since roughed out two bowls without much trouble.

The biggest thing for me was the process and tool presentation. The DVDs help reenforce the things that Steve taught me.

He also loaned a couple of DVDs to me and they are very helpful. One is the Bill Grumbine and the other is Richard Raffan - Turning Wood.

I will probably end up buying these two. I also have been looking at videos on using a skew.