# Hollow form advice



## kweinert (Sep 1, 2012)

So, I'm trying to turn my first hollow form. it's an end grain form in BKP.

I just want to be sure I'm 'doing it right' or, at least, having a normal experience :)

I have a tool like the one that woodtickgreg made (but with less curve in the rod) and it's sort of 'catching' as I turn. This is about 8" deep and 5-6 inches in diameter at the largest.

Because the rod is round it's very easy to rotate when I'm turning (so 'catch' is a bit strong of a word to use - maybe 'grab' would be better.)

If this is normal, no worries. I'm just trying to find out if there's something I should be doing differently or if I'm on the right track and I'm just learning something new.

Thanks.

Ken


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## DKMD (Sep 1, 2012)

For the most part, you shouldn't be experiencing catches, but some of the carbide cutters can be a bit grabby in my hands. Depending on the size of the rod and the size of the cutter, 8" of overhang can be a real trick with smaller tools and larger cutter. Remember to clear chips often especially early in the hollowing. Of you keep having 'issues', some photos might helpful.


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## NYWoodturner (Sep 1, 2012)

Every tool is different - so it is really hard to answer based on what you have said - but I would play with approach. More angle can "soften" contact and therefore reduce grabs. I would also try starting at the front near the tool rest and riding to the back uphill. Listen to the different sounds different approaches make. The sound that feels the smoothest is the right approach. I was taught that by a blind turner at the 2011 AAW symposium. He was amazing


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## woodtickgreg (Sep 1, 2012)

Ken, can you post a pic of that tool, especially the cutter? I think I know what you are using but not sure. If we can see it better advice may follow.


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## kweinert (Sep 1, 2012)

OK, so since it doesn't exist without pictures, here are some pictures :)

First, progress so far: 

[attachment=9924]

[attachment=9925]

[attachment=9926]

It does have a coat of lacquer on the outside and just inside the lip.

And now the tool (and Greg, I used the same handle for your tool but it has too much curve to fit inside the opening):

[attachment=9927]

[attachment=9928]

So, it's not going too bad. And yes, I probably could have used an easier shape to start with but this is what the wood wanted to look like.

This is the only piece of BKP I've seen that radiates out from the center. Someone told me this happened because the tree got infected near the top and it traveled down the center of the tree.

Well, i do have another one that looks just like this - it's the other half of the piece of log that was brought to me :)


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## woodtickgreg (Sep 1, 2012)

Ken. that is what I expected the tool to look like. That type of tool works better with a slight angle downward. It's more of a scrapping style of tool. The handle you chose has a nice nurling on it so you should have a good grip on it. Light cuts are the key to that tool or you will really have to muscle it as it will want to roll on the round shank.


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## DKMD (Sep 1, 2012)

If I'm not mistaken, that shaft is 3/8" diameter and the handle is pretty short… I've got one that looks a lot like it. That's an awfully big form for a tool that size. Even if it were 1/2", it would still be tough for me to go 7 or 8 inches deep with a bar that size.


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## kweinert (Sep 1, 2012)

Thanks guys.

i had determined that things seemed to go better when I had more of a downward tilt to the cutter.

And what you're both saying is that my lack of experience is once again being a primary factor in me gaining experience. 

Some random thoughts follow:

I'm thinking I should go throw that 24" piece of ash on the other lathe and turn myself a handle :)

I didn't really think of this as being all that large of a form.

If the opening were a bit larger I'd use the tool you made for me - i can certainly see the advantage of the flat bar for going deep into a form.

Ken


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## woodtickgreg (Sep 1, 2012)

kweinert said:


> Thanks guys.
> If the opening were a bit larger I'd use the tool you made for me - i can certainly see the advantage of the flat bar for going deep into a form.
> 
> Ken


Ken If you have not used that tool yet you are in for a big surprise, The wide flat on that tool makes it very stable. That tool is used flat on the rest, a long handle is an advantage.


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## dean jordan (Sep 1, 2012)

Hi there here is my 2cents.
If you hold that tool with the cutter level and slightly above center it should not catch. Another thing that might help is to drill a large hole to the bottom of your HF. Even a 1in spade bit will do the job
The wood at the center is hardly turning and that tool is not especialy good at end grain cuttingIt looks like youre doing a great job


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## kweinert (Sep 1, 2012)

woodtickgreg said:


> kweinert said:
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> > Thanks guys.
> ...



I used it a little, but not to its best advantage. I started using it after I did the initial boring for the opening but at that point it was pretty much on the round bar.

Yes, i should have moved the tool rest back farther and used the flat - but sometimes I'm a slow learner :)


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## kweinert (Sep 1, 2012)

dean jordan said:


> Hi there here is my 2cents.
> If you hold that tool with the cutter level and slightly above center it should not catch. Another thing that might help is to drill a large hole to the bottom of your HF. Even a 1in spade bit will do the job
> The wood at the center is hardly turning and that tool is not especialy good at end grain cuttingIt looks like youre doing a great job



Thanks for the advice.

I started out with boring a 1 1/4" hole with a Forstner bit as deep as I could go. I guess I need to pick up an extension so I can drill the initial hole a bit deeper.

I did get one catch that pulled the tenon out of the chuck, but in general I'd say that I'm getting more of a grab with the tool having a tendency to roll and perhaps chatter a bit.

I'm just trying to figure out if I'm proceeding correctly and from what you folks have said I am doing things approximately correct - just might be overstepping my experience a bit. 

That's nothing new.

Ken


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## woodtickgreg (Sep 1, 2012)

kweinert said:


> dean jordan said:
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> 
> > Hi there here is my 2cents.
> ...


Yes, bore a hole to fell depth, makes the hollowing much easier. Your learning Ken! Keep at it. And when you use my tool keep the wide flat on the rest.


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## kweinert (Sep 6, 2012)

So, I took in the piece and a couple of the tools I'm using to the Front Range Woodturners meeting on Tuesday and got some advice.

Mainly that the tool I'm using (not yours, Greg) is more of a scraper (which I knew) but it's a bit too big which is why it's a bit grabby. He recommended a longer handle (which I had thought about) and a smaller cutter.

He also recommended that I turn an oval handle as that would make it easier to know where the tip is and make it easier to hold on to and not let it grab as much.

I think the next problem I'm going have is that I'll have to be putting the handle on the tool rest in order to get in deep enough. That's not ideal - but is it dangerous?

I'll be throwing this back on the lathe here shortly and seeing what I can do.

I appreciate all the advice from you all.


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## DKMD (Sep 6, 2012)

I'd vote no on the handle on the tool rest... I don't think you'll have the control that you need.


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## kweinert (Sep 6, 2012)

DKMD said:


> I'd vote no on the handle on the tool rest... I don't think you'll have the control that you need.



Then I guess I'll need to get longer tools as well :) I think Greg's is probably long enough, it's just got too much curve to fit down inside. Even my 'normal' gouges and such are too short to reach.

I guess I'll be working on smaller hollow forms for a while.

Ken


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## woodtickgreg (Sep 6, 2012)

kweinert said:


> DKMD said:
> 
> 
> > I'd vote no on the handle on the tool rest... I don't think you'll have the control that you need.
> ...


Definate no on putting the handle on the rest. Ken, you really should use the tool I made you. It's super stable and easy to use, just crank up the speed. If I remember right you did put a long handle on it? Don't get to hung up on the size of the hole, be more concerned on working on your technique. With my tool you should be able to get about 7" or maybe a little more deep.


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## kweinert (Sep 6, 2012)

woodtickgreg said:


> kweinert said:
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I think the problem with your tool is the shape of my form.

If you look at the pictures you can see that I have a long neck on mine and your tool doesn't fit inside it.

Yep, probably a dumb shape for someone starting out. On the other hand, I am learning a lot :)

Most of my other (normal) tools are too short to fit in and get the depth I'm looking at. In addition I'm about ready to try to take them out of their wooden handles to see if I can put them in one of the 'after market' ones. I am learning why people like tools with long handles.

It's a learning experience all right - sort of frustrating at the moment but I'm guessing that these lessons will stick with me for a while.

Ken


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## woodtickgreg (Sep 6, 2012)

kweinert said:


> woodtickgreg said:
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> > kweinert said:
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I didn't mean to use the tool on this project, but your next ones :lolol: That thing really cuts well and is really stable once you learn how deep a cut to take. It's always a learning curve my friend, if I wasn't still learning it wouldn't be any fun!


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## DKMD (Sep 6, 2012)

Ken, you can make cheap hollowing tools from cold rolled steel and HSS cutters. The local big box store sells cold rolled in a number of sizes, and I get my HSS cutters from Enco. If you drill the end of the steel rod at a 45 degree angle and glue in the cutter(or use a set screw), you'll have a tool that will probably get under that shoulder. You can bend the cold rolled with a MAP torch if you want a swan neck shape. Greg's tool will be much easier to use since it's got a wide flat surface to set on the rest, but the homemade tools come in handy at times.


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## kweinert (Sep 7, 2012)

DKMD said:


> Ken, you can make cheap hollowing tools from cold rolled steel and HSS cutters. The local big box store sells cold rolled in a number of sizes, and I get my HSS cutters from Enco. If you drill the end of the steel rod at a 45 degree angle and glue in the cutter(or use a set screw), you'll have a tool that will probably get under that shoulder. You can bend the cold rolled with a MAP torch if you want a swan neck shape. Greg's tool will be much easier to use since it's got a wide flat surface to set on the rest, but the homemade tools come in handy at times.



I'm having trouble visualizing the 'drill the end of the steel rod at a 45 degree angle' part.

Also, can I get a better idea of what you mean by 'MAP torch' please? I've tried looking it up and that seems to be a general term for several different things so I'm just curious what, exactly, you're talking about. I'm a complete novice on this subject so any pointers/assistance will be greatly appreciated.

If I can bend with the MAP torch can I braze with it? I only ask because I was thinking I could to a pseudo-greg tool by attaching another length of the CRS beside the main 'stem' of the tool. A poor substitute for sure, but it might be worthwhile.

Also, I just looked at Enco and got lost - do you have a part number or catalog page that would get me started in the right direction?

Thanks.

Ken


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## DKMD (Sep 7, 2012)

kweinert said:


> DKMD said:
> 
> 
> > Ken, you can make cheap hollowing tools from cold rolled steel and HSS cutters. The local big box store sells cold rolled in a number of sizes, and I get my HSS cutters from Enco. If you drill the end of the steel rod at a 45 degree angle and glue in the cutter(or use a set screw), you'll have a tool that will probably get under that shoulder. You can bend the cold rolled with a MAP torch if you want a swan neck shape. Greg's tool will be much easier to use since it's got a wide flat surface to set on the rest, but the homemade tools come in handy at times.
> ...



Here's the link to the 3/16" cutters I get from Enco. I usually cut them in half, so I get two cutters out of each one.

http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=383-5312&PMPXNO=939775

Here's a link to a tutorial on making your own hollowing tools:

http://woodturnersamerica.com/index.php?option=com_content&view=article&id=69:making-boring-bars-for-hollowing&catid=39:hollowing&Itemid=109

MAPP torches(propylene) are a lot like propane torches, but I think they burn hotter. You might be able to use a regular propane torch, but it'll take even longer to heat the steel. Something like this although you can probably find them cheaper:

http://www1.mscdirect.com/cgi/NNSRIT2?PMAKA=57775744&PMPXNO=34572442&cm_re=ItemDetail-_-ResultListing-_-SearchResults

If you know someone that welds, you may be able to convince them to bend the rods for you. I have no clue about brazing stuff, but there are some folks around here that are a lot smarter than I am about that kind of stuff.

Keep the questions coming!


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## kweinert (Sep 7, 2012)

DKMD said:


> kweinert said:
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Thanks for the links and the information. I was looking for a different type of cutter which probably explains why I wasn't seeing what I was expecting - and why your original post wasn't making a picture in my mind.

I was thinking you were talking about the kind of cutters that Greg uses in his tools and I wasn't seeing anything like that :)

Since my hollow form barely qualifies as one now I think Greg's tool will fit in there - but I'm going to have to give this a go as well I think.

Ken


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