Back in the saddle...need advice

[John Hart]

Howdy,

I finally got the lathe going and ran into a problem right out of the gate. It seems I might be a bit heavy handed on my approach, because I broke the first three pieces I tried....all in the same way. All three were set up with a faceplate and the outer profile was cut, then when I turned it around and mounted to the chuck, I applied too much pressure and broke my foot off in the chuck. Two of the pieces, I just threw in the fireplace, but this one, I decided to keep...if it's possible to save.

This is Willow I think. Heavily spalted and the bottom is about the consistency and texture of balsa wood. Well...maybe not that bad...but anyway, it's pretty fragile. I don't think the chuck is going to work out, but I can get it remounted to the face plate and create an alternative.

Any ideas how I should approach this?:rolleyes:

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[Liem Tran]

Did you try mounting it between centers to turn a new tenon?
That might work.



Liem

[John Hart]

Did you try mounting it between centers to turn a new tenon?
That might work.

Nope...I really haven't tried anything yet Liem. My biggest fear is that a new tenon is just going to break off again. You can see the piece left in the chuck. It just tore off. I can try to me more gentle I suppose.:o

[Travis Stinson]

Try soaking some thin CA or something to strengthen the tenon area. Those spalt lines are pretty weak.

[Dennis Peacock]

Hey John,

Try this:

Mount between centers or put back on the faceplate.
Turn new tenon.
Take off the lathe and mount your chuck.
Put the piece in the chuck and "snug" the jaws down on it.
Bring up the tailstock to pin it between "centers if you will".
Turn just a "little" from the outside of the form.
Stop the lathe and snug it again.
Do as much turning as you can without removing the tailstock.
Once done, remove the tailstock and finish the turning with lite cuts with a sharp tool.
Too much stress on the joint as well as over-tightening can cause tenon failure. DAMHIKT!!!! :rolleyes:

[Ted Calver]

John,
Couple of things come to mind...First, after you mount it in the chuck bring the tail stock back up and keep it in place as long as you can while you start hollowing. It will help control some of the initial torque. Second, think about building yourself one of those hollow form bowl steadies out of all thread and in-line skate wheels. That will help hold the bowl steady. Another thought is to take a look at your hollowing technique and or tools--make the right cut with the right tool. I'm sure others will chime in too.

[Steve Schlumpf]

John, have to agree with everyone in that I suggest you use the tail stock until you have the bowl just about hollowed out. I am sure you have more experience than I do in this but sometimes when turning spalded birch - and having the same problems you are now - it is the only thing that has worked for me.

[Ken Fitzgerald]

I applied too much pressure and broke my foot off in the chuck.
Any ideas how I should approach this?:rolleyes:

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My advice is to not put your foot in the chuck. And if you do....I'd approach the idea with exteme caution and concern for your physical well being John!:eek: :rolleyes: :D


Good luck with that wood. Sure looks pretty...I really don't know what to tell you about the blank.

[Andy Hoyt]

You're getting good advice, John.

With crummy wood like this stuff, it's really easy to overtighten the chuck. So a gentle snug is about the right amount of torque to apply. And given the state of the wood and the depth of the vessel, early cuts (probably with the Ugly Stick) is putting too much stress on the weakest link in the chain. so a bowl steady would likely help here by taking up some that load.

[John Hart]

Yup...didn't think about the overtightening problem. I bet I overwrenched on all three of the pieces I tried. I'm going to take all this advice. I'll mount it up and turn a tenon....then soak it in some CA....then without using my foot in the chuck;) , I'll mount it up and bring up the tailstock for support. Don't have a steady yet, but I oughta be able to finesse this guy to its finish.

Thanks everyone!!:) I'll let you know how it goes.

[Curt Fuller]

John, after you figure out the best way for you to re-turn a tenon, mount it in the chuck again and take all that good tight but not too tight advice. Then bring up the tail stick and put a little pressure on the bowl so that it's not so likely to break off the tenon again. Then hollow the bowl with the tailstock in place leaving a center "post" about an inch in diameter for the tailstock. Once you get it close to as deep as you want it you can back off the tailstock and turn off that post. By then you have it to a point where you're not putting as much torque on the tenon and you can just take some light cuts to finish it. That usually works for me.

Good luck!

[Bernie Weishapl]

John I had the same problem a while back. I kept breaking of the tenon. I busted it 3 times. I finally put a final tenon on it and then soaked it is the old epoxy cocktail. It worked. So I think either CA or this would work. I agree with the tailstock up and do most of your hogging of wood off. Then move the tailstock away and take light cuts. Let us know how it goes John.

[Jim Bell]

Keep tools rador sharp and take light cuts.
Jim

[Gary DeWitt]

On turning with the tailstock until you have a "post", I think I saw a turner on a video break that post off, then finish the inside bottom of the vessel.

What about that stuff I've seen in the store designed to harden up rotted wood? Already mixed, and I'm sure not as expensive as CA. I haven't used it, but I think you could re-turn your tennon, soak it in that stuff, then turn the rest of the piece, using the tailstock when possible. Just an idea...

[John Hart]

Thanks again fellers!!:) I've heard of that wood hardener stuff but never seen it. I'm sure all I have to do is look harder. The epoxy manhatten does work pretty good for controlling tearout....I bet it would work in this scenario as well. I really want to keep this piece so I reckon I'll just keep the grinder spinning and do the tailstock thing. I did that a lot when I was first starting out and didn't have very good fixtures. Time to go back to the fundamentals.;) :)

[Ron Sardo]

Did you cut a dovetail on the tenon?

[Jim Becker]

Remount reversed with a worm-screw in your chuck and recut the tenon. Be sure you have a shoulder for the top of the jaws to rest on to provide support. A tenon will break off much more easily if that little step is forgotten. And if the wood is really soft and punky, despite the risk to finishing options, use something to harden it if you can.

[Jim Stoppleworth]

In the past with punky wood, instead of cutting a new tenon I've cut a mortice and expanded the chuck into it with success. I've also had success with cutting the new tenon and soaking the area around it with CA.


Jim

[Jim Becker]

The only issue with a recess in a bowl form is that there is limited support available to the jaws on anything but a very flat form.

[Frank Kobilsek]

John

One more altnernative might be to put your bigger jaws on the chuck, reshape the outside, flip to the inside, then jam or cole chuck it to return the bottom foot ... plus the area around the foot. Maybe big design change, but not firewood.

I know that coring with my Woodcut system and 4" jaws in my Stronghold is easy AND that coring with the 2" jaws is full of ejection possibilities.

Frank

[John Hart]

Did you cut a dovetail on the tenon?

Yup...sure did. A pretty nice one. And it held so well that it stayed in the chuck as its guts were being torn out. :D


Frank...I just don't have bigger jaws. :o Do elves make Chucks?:confused:


Jim S...I did try the mortise idea on one of the other pieces (that went in the fire)....It didn't last 10 revolutions. That spalted wood just wouldn't hold up. Another reason to strengthen it up a bit.:)

[Jim Becker]

John...does your chuck want a dovetail shape on the tenon? OneWay doesn't, for example. Unless the chuck jaws demand the taper, avoid it as it weakens the tenon and the grip you have on it. And again, don't forget the shoulder.

[Gary DeWitt]

Ya know, we're probably the only group of craftsmen (craftspeople?) who get excited about using the worst material we can find! I've seen the hardener in the finishes section at Loews and Home Depot, not sure what you have around your neck of the woods.
Did any of the above work for you? I havn't run across punky wood yet, but it's only a matter of time...

[George Tokarev]

The only issue with a recess in a bowl form is that there is limited support available to the jaws on anything but a very flat form.

Not really. You're neglecting the real contact point, the face of the jaws against the bottom of the mortise. That's where the stress is taken, just as in flat work, where the shoulders around the tenon resist racking forces. The pin or glue, or as in this case, wedge, merely keep the important parts in register. That's why you don't have to tighten more than snug enough to draw the components together. All you need there is enough resistance to keep it from rotating, and that's not a lot, given the main stress of cutting is down toward the shoulder. Or should be, if you're trying to avoid tearout.

For ring-porous woods like oak or ash, where they're likely to separate along the porous zone, CA can be a real help. Be sure to clean off surface irregularities you might have built with the CA, and get stray sanding dust or shavings out of the mortise to get the best surface-to surface contact. Then let the dovetail do what dovetails do, center in the mortise or around the tenon, and draw up against the shoulder.

[Curt Fuller]

Ya know, we're probably the only group of craftsmen (craftspeople?) who get excited about using the worst material we can find! I've seen the hardener in the finishes section at Loews and Home Depot, not sure what you have around your neck of the woods.
Did any of the above work for you? I havn't run across punky wood yet, but it's only a matter of time...

Boy ain't that the truth. Rottener, gnarlyer, punkyer, spalteder the better.

[John Hart]

John...does your chuck want a dovetail shape on the tenon? OneWay doesn't, for example. Unless the chuck jaws demand the taper, avoid it as it weakens the tenon and the grip you have on it. And again, don't forget the shoulder.

Yep....I try to get my dovetail to match perfectly with the chuck....kinda anal about it really.:rolleyes: But I do try to get a real good sng fit to the face of the jaws to the shoulder. I keep going over this in my head and I really think I wrenched on it too hard...probably caused a break at the edge of the tenon-to-the-shoulder. I've been away too long.:(

[John Hart]

Ya know, we're probably the only group of craftsmen (craftspeople?) who get excited about using the worst material we can find! I've seen the hardener in the finishes section at Loews and Home Depot, not sure what you have around your neck of the woods.
Did any of the above work for you? I havn't run across punky wood yet, but it's only a matter of time...

Yeah...we have all the HDs and Loews....but I've never seen a hardener...that I know of. Whats the name of the product?

Oh...nope...haven't done it yet. It's mamma's birthday today. Been getting ready for that.

[Gary DeWitt]

Here ya go, John.
http://www.minwax.com/products/woodmaint/hardener.cfm
Like I said, I've never used it, so you might want to try it on a scrap first. No sense testing on something so nice you already have so much time in.

[Glenn Hodges]

John I had this problem with some chestnut the other day. After I recovered the bowl with the broken tendon from across the room, I turned a new flat place on the bottom and put a faceplate on it with screws. No problem after that.

[Keith Burns]

John, I had the same experience as you when I started turning green wood. What I do now is coat the tenon with CA glue before I re-mount it for finish turning. That along with trying to limit my tightening. Also use a 4 wheel steady rest on larger pieces. Seems to have worked for me.

[Mark Cothren]

Well, how'd it end up????

[John Hart]

Well, how'd it end up????

ummmm...well...I uh....haven't started yet.:o Between getting a snowblower up and running, moving turning blanks from the old house to the new house, and my wife's birthday....I haven't made it to the lathe in a few days. Snow's tapering off today, so maybe tonight....definitely have some time slots over the weekend. I figger I can get the tenon cut and soaked in CA or Wood Hardener (if I can find some) tonight though.

[Barry Stratton]

Good to see you thinking about the lathe, Mr. Hart!!!

And come up for a visit, we'll teach you how to handle "snow"!!!!!:D

http://www.city-data.com/cpicv/vfiles10802.jpg

[John Hart]

Good to see you thinking about the lathe, Mr. Hart!!!

And come up for a visit, we'll teach you how to handle "snow"!!!!!:D



I've already handled Alaskan Snow....And I loved it!! 'Course.....I lived on the Aleutians....not quite the same as the magnificence of the mainland.

Oh by the way Mr Stratton.....I still have your scroll work ready to go....with the first box dried and ready. Amazing that I kept track of all of it. Now....if I can just buy some time from someone.:rolleyes:

[John Hart]

Ok....I took the advice and gave 'er a whirl.

Mounted it back up to the faceplate and cut a new tenon
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Then doused it with CA
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and turned it around, mounted it to the chuck...snugged up the tailstock and hollowed it out...Then cut off the pillar that was in the center.
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It all worked out well....'cept for the fact that this wood is just HORRIBLE to work with. Decided that it really needs an Epoxy-Manhattan bath before I go any further. Had too many other things I wanted to get done today, so the bath is on hold for a few days anyway.

Thanks everyone for all the helpful hints!

[Andy Hoyt]

Well there ya go, John. Glad it worked out.

Nice tear out! Reminds me of some hickory we had a while back. Want some more?:D:cool::eek::D:cool::eek:

[George Tokarev]

And come up for a visit, we'll teach you how to handle "snow"!!!!!:D


That out on the Kenai? Never had much snow when we were up there (10th & Karluk). Earthquakes, sure, but having gone to school in two "lake effect" towns, I never thought much of the snow problem. NOAA says seventy average, which seems about right. I've seen that on the level here.

Just got back in from shoeing on about a foot of lake effect after a warm day. Hoping it's first of the season aches not age. A mile seemed a lot.

[George Tokarev]

It all worked out well....'cept for the fact that this wood is just HORRIBLE to work with. Decided that it really needs an Epoxy-Manhattan bath before I go any further.

Some pieces of wood deserve to return to the firewood stack from whence they came.

This one had a bit of drying to do before it could even do that. Yes, that's a handful of what was once wood resting in that hole.

[John Hart]

Some pieces of wood deserve to return to the firewood stack from whence they came....

I'm thinkin' about it!;) :)

That piece of yours sure woulda been pretty if it survived George!