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crack while turning bowl

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Forum topic by Karda posted 06-21-2017 01:27 AM 656 views 0 times favorited 18 replies Add to Favorites Watch
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Karda

823 posts in 393 days


06-21-2017 01:27 AM

when turning a bowl, i start in the center of the bottom and travel left to the side, and as I start up the side there is a lot crack, sounds like a gun shot. when i am cutting across the bottom I am cutting not quite with the point and not quite with the wing . does any body know what i am doing wrong. I have watched a number of videos but am still doing something wrong


18 replies so far

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papadan

3584 posts in 3207 days


#1 posted 06-21-2017 02:40 AM

Are you turning green wood?

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Karda

823 posts in 393 days


#2 posted 06-21-2017 03:07 AM

it happens with green and with the bowl I turned from 2xs, I am working with one Jerry sent me I don’t know if thsat is still green or not.

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papadan

3584 posts in 3207 days


#3 posted 06-21-2017 03:41 AM

Turning green wood you need to leave it well oversized and let it dry, then go back and turn it to the finished size. You could have got a catch, had a defect in the bowl blank, it’s hard to say without seeing the piece. Just for reference, I always turn the outside first, then turn the inside from the lip down the side and across the bottom. Just the opposite of what you were doing when it split.

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Karda

823 posts in 393 days


#4 posted 06-21-2017 03:44 AM

I have done it both ways and when it works going across the bottom and up the side cuts much better than down. I just can’t figure what I am doing wong

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Rick_M

10640 posts in 2219 days


#5 posted 06-21-2017 04:23 AM

Chuck too tight? As you turn it down the wood weakens and cracks maybe. Do you have the chuck jaws in a recess?

-- http://thewoodknack.blogspot.com/

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KelleyCrafts

2680 posts in 578 days


#6 posted 06-21-2017 05:53 AM

I do like Dan does and works out fine. When I first started I would wrench the jaws down too much like Rick is talking about. I’ve had a bowl fly off the chuck before, lesson learned. Great input here from both.

-- http://kelleycrafts.com/ - pen blanks - knife scales - turning tools

View Nubsnstubs's profile

Nubsnstubs

1207 posts in 1569 days


#7 posted 06-21-2017 02:36 PM

Mike, is my wood giving you a problem??? Say it ain’t so…. First and foremost. It’s Mesquite. Excellent wood to turn. Very stable. And, it is dry, but even if it wasn’t, the problem you described is operator error. It sounds like tool introduction is in order.

You get your gouge, go up to the tool rest, lay it on the rest at open flute, gouge edges at horizontal, and start your introduction. Goes like this, “Mr. Velvet Mesquite, this is MR. _ (insert brand name) Gouge. Now what I’m about to do to you is turn you into a work of art. Any objections”? That ritual MUST be performed daily when turning anything. It settles the issue as to who is the boss.

Start at the lip and work towards the center rubbing the bevel on the Bowl gouge you should be using. Put the heel up against the side of the form, rotate it from 12 o’clock towards 11 o’clock until wood stars to shave off the wood, then proceed to cut towards the middle still rotating the tool tip shaving off only that little bit of wood started at the beginning.

Repeat until you get the process figured out. I think that is the proper way, but after awhile, it’s so natural you forget what the proper technique is and just do what works best, but going from the lip to the middle is the best way. You can scrape back with a bowl gouge, but it’s best to cut into the wood rather than scrape. I rarely cut from the center to the lip as I get those gunshots too and projectiles to worry about also. ...... Jerry (in Tucson)

How did you mount this particular piece. If I remember correctly, there were no tenons on what I sent you?? ........ Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

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Karda

823 posts in 393 days


#8 posted 06-21-2017 06:14 PM

Hi, first off it is not the wood, Mesquite is a sweet turning wish it grew around here,it is definitely operator error. I have done it that way and it work very well when it works. some times it wont happen but others that all that happens. I guess until I get more experience I go down the side and across. I never thought of talking to the wood, I hope the wood listens better than my cat.
I mounted this bowl into a recessed glue block

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papadan

3584 posts in 3207 days


#9 posted 06-21-2017 06:21 PM

Mike, I hope the wood listens better than you do! LOL You’ve got the fundamentals now, you can stop trying to make something good out of construction lumber.

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Nubsnstubs

1207 posts in 1569 days


#10 posted 06-21-2017 06:44 PM

And, you also have to do a little dance while rubbing the bevel. Don’t believe it, ask the experienced guys. They’ll say, “It’s all in how you move”.

When you have the outside/inside finished, make yourself another recessed block that is a tight fit at the rim of the bowl. jam the bowl into the block or now a jam chuck, bring up the tailstock, and proceed to hog off some of that foot. if that’s the bowl I sent, the bottom should be about a 1/4” when done. Leave just a little foot showing..

Did I do those rings shown on the rim, or did you do that?

This picture is pretty good compared to some in the past of your gouge. Take another and post it of the gouge you are introducing to Mr. Mesquite…........ ....... Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

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Karda

823 posts in 393 days


#11 posted 06-21-2017 06:46 PM

the construction lumber was desperation, I had my bowl gouge for a couple weeks and had used it only on some spindle practice. I know its not the best but its wood, Yea I know I am quite thick sometimes

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Karda

823 posts in 393 days


#12 posted 06-21-2017 09:16 PM

I know about the dance, but I am not a good dancer, I do what I can to get the gouge to cut. The step angle to the edge does work better for the bottom of the bowl but in other areas don’t o work so well, of course I don’t know what I am doing. I’ll try to take better picture of the gouge for some reason when I crop and resize it make the picture blurry.
The ridges on the lip are an accident the gouge must have touched the lip. I like the look I try to do that to the finished piece

View MrUnix's profile

MrUnix

6012 posts in 2038 days


#13 posted 06-21-2017 10:52 PM

Not related to your problem, but why did you put the recess in the glue block? Seems like it would just make it harder to part off or separate once you are finished turning.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

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Karda

823 posts in 393 days


#14 posted 06-21-2017 11:45 PM

The glue block is threaded so by turning a recess I was able to center the piece accurately, very uncommon for me to think like that but Jerry gave me the idea. here are the pictures of my gouge, a half inch bowl gouge

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Nubsnstubs

1207 posts in 1569 days


#15 posted 06-22-2017 01:10 AM



Not related to your problem, but why did you put the recess in the glue block? Seems like it would just make it harder to part off or separate once you are finished turning.

Cheers,
Brad

- MrUnix


Brad, when I sent him the roughs, there was no way for him to center them accurately. If he had a chuck at the time, I would have sent the pieces with the tenons still on them. It looks like he’s starting to figure some things out because he’s followed some of our advice. I was going to do a video, but I started confusing my self as I was trying to set them up for a face plate, but without even owning one, I got confused about how to get this done. If that piece is the one I think it is, he’ll be able to part if off pretty easily as the foot is only a 1/2” ring turned into the bottom with a recess to give the necessary clearance.

You’re doing good, Mike. When do you think this will be done? Waiting for more pictures…....

My grind is at 51 degrees. It’s what works best for me. Your grind looks pretty good. Use the heel to set the tool against the wood, then do that rotate thing I mentioned earlier. Hang your tongue out on the left side while doing that dance. It makes things better…. and use English. ............. Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

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