# Redwood Hollow Form build thread



## NYWoodturner (Jan 17, 2015)

OK - This will include some Do's and some Don'ts. First off I have to give a nod to Mark Sanger over at WTU. He is the one that I got this method from, although I think his method might be better. Its been so long since I read it my memory fades a bit. 



 
Starting with a block of Redwood, 4.25x4.25x8. This is your first Don't - Don't cajole a softwood for this method. You'll learn why later. 



 
Round it and square both ends. Cut a tenon on both ends.



The first step is the tenon. The second step is actually going to be the "plug". This will get a bit thicker because I will lose some is parting it off. 


 
Here I've just put a couple of lines on the blank to get an idea of where the bottom of the form will be and where the widest point of the shoulder will be. I tend to not do a lot of pre-planning. I normally develop a shape while I'm turning. In this case however I have to have a target for the base of the form.



 
Here is where the second step or "plug" gets a bit deeper. The left side of the second step is now the base of the form. I can start rough shaping up to the shoulder.



 
Here I have narrowed the diameter of the plug. I know the base will be a smaller diameter so I narrow the plug to allow for more shaping.



 
Refining the shape.



 
Now its time to part off the bottom tenon. It still has the plug attached, which will allow me to chuck it and turn the plug down to final dimensions. Here is another DON'T. Don't forget to mark a line on both sides to use to line up the grain later. I use a Japanese pull saw to make final parting cuts with. I will part it with a chisel down to between 1/2 and 1/4" then use the saw. In this case you need to have no damage to the piece you are parting off.

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## Sprung (Jan 17, 2015)

Subscribed!


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## NYWoodturner (Jan 17, 2015)

I use a #2 MT 1" drill bit to start hollowing. I eyeball the depth and use blue painters tape as a depth gauge.

I missed a pic here - but it is critical that you square the bottom after hollowing. It has to be a perfect 90 degrees. 89.5 will leave you will a nasty ugly glue line that will be visible from across the room.








One thing you can do when a perfect 90 is critical is use a machinist's square to square your banjo on the ways, and then use the banjo as a sight line.








Check for any final hollowing needs. The base wall right now is 1/2 inch thick. This is the thickest part of the form. There is a lot of reshaping to do once its closed up.
This is the point where you realize the importance of shaping the outside as close to final dimensions as possible. You are hollowing blind on the inside, but whatever shape you hollow determines what you can or cannot do in your final shaping. I don't have a laser or a hollowing rig, so I go by feel and sound. Getting the same pitch along the wall gets you a pretty even wall thickness. When it gets to about 3/16 the sound changes completely. 






The walls are at 1/4"

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## NYWoodturner (Jan 17, 2015)

Now its time to turn the plug to final diameter.


 
I use a caliper set to a touch bigger than needed. This way I can sand and sneak up on a perfect fit.



 
You need a tenon perfectly square to the base of the form and the base of the plug as well as a snug fit around the tenon. This also gives you quite a bit of adhesion surface area. 



 
The form is now glued onto the plug. I use the tailstock to hold it in place and apply pressure. Normally I would use Titebond wood glue here. CA stains redwood. Tibetan would have to dry overnight so for the sake of time I used CA. 



 
Start the final shaping of the base. You can see how dark the CA is on the redwood. 



 
Shaping the neck and refine the shape of the form.



 
You want to start sanding at this point. This is sanded through the grits to 400. 



 
Further refining the base. This is when you determine where that glue line ends up. If I continue down with the curve the line ends up on the side. If I cut in here I can put the line on the bottom, which is preferable iMO.

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## NYWoodturner (Jan 17, 2015)

Shaping the neck and collar.


 
Drilling through the neck. I use a collet chuck in the tailstock. I then start shaping the collar and...



 
The tenon I had turned at the base snapped. This is why I say don't choose a soft wood for this. There was little to no pressure being applied when this thing went. So now I have a piece with neither end finished. This is where a vacuum chuck is invaluable. If you don't have a vacuum chuck you could do the same with a jamb chuck you turn and the tailstock. 



 
This is when I should have walked away for a while and didn't. I got aggravated because the stem snapped and I had to replace the neoprene gasket on the couch drum. Instead of fidgeting with the form in the vacuum chuck until I got it dead true, I just called it close enough. This is what you get when you settle for close enough - There is no such thing... 
Normally you would embellish over the line with a chatter tool, beads, or whatever your creativity comes up with. Here you can see the form was not dead center so it produced a sloppy result. If there was enough meat left I could cut this off and start over but there wasn't. I was getting "that" sound. 

The next DONT is don't keep going when your aggravated.



 
Here I am shaping the collar when it breaks. Again - soft wood is not the best choice for this style of turning. I never even heard this piece come off. 
This is what's known as a "design opportunity" 




Here is the new design.

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## NYWoodturner (Jan 17, 2015)

This si with a couple coats of finish - thinned out varnish. You can see its sucking it up. I'll post a pic tomorrow with a few more coats. 
With a little more time and attention you can get a much nicer conceal on the base. You can also place the seam anywhere on the piece that you like. If t will blend it with a bead or a cove, a collar or segment line you can make it practically invisible.

Hope this helped!

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## SENC (Jan 17, 2015)

Excellent thread, Scott!

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## DKMD (Jan 17, 2015)

That's awesome! I've only done small scale stuff from the bottom, but I'm some enamored with the pouty little tops that I'll have to give this a try. Thanks for the play-by-play!

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## barry richardson (Jan 17, 2015)

Bravo Scott! I really enjoyed it, thanks for the post

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## Schroedc (Jan 17, 2015)

Wow! I'm thinking that I'm going to have to give one of these a whirl once the shop is heated again. Thank you!

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## gman2431 (Jan 18, 2015)

If your tenon wouldn't have snapped would you have parted the piece off?

Awesome thread also! Between this and the two piece hollow form my wheels are spinning!


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## West River WoodWorks (Jan 18, 2015)

Awesome, thanks for all the ins and outs!


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## NYWoodturner (Jan 18, 2015)

gman2431 said:


> If your tenon wouldn't have snapped would you have parted the piece off?
> 
> Awesome thread also! Between this and the two piece hollow form my wheels are spinning!


Yes. I would have finished that original neck with it on true center and likely would not have had the break that I did. After finishing the opening I would have nibbled away at that tenon and done a much better job of finishing the bottom with it on center. Then I would have parted off the last 1/4 inch.

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## Mike Jones (Jan 18, 2015)

Here is a suggestion: Make your bottom hole and plug tapered, rather than straight. Doing this makes the fit-up faster, without having to "sneak-up" with sandpaper. Tapered, the plug will find "home", will be tight, and will make the bonding surfaces a bit larger.

I think that I would be tempted to glue up a piece at the neck, to re-make the original design idea.

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## NYWoodturner (Jan 18, 2015)

Mike Jones said:


> Here is a suggestion: Make your bottom hole and plug tapered, rather than straight. Doing this makes the fit-up faster, without having to "sneak-up" with sandpaper. Tapered, the plug will find "home", will be tight, and will make the bonding surfaces a bit larger.
> 
> I think that I would be tempted to glue up a piece at the neck, to re-make the original design idea.


I have used the tapered method also. If you get the same angle on the plug and the base it works like a dream. If you don't you get a super thin glue line. If you accidentally go through it theres no recovering. If I am using a wood were grain match is critical I use this method.

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## Ajctg2 (Jan 18, 2015)

That was amazing to see come together. Great post!


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## Mike Jones (Jan 20, 2015)

NYWoodturner said:


> I have used the tapered method also. If you get the same angle on the plug and the base it works like a dream. If you don't you get a super thin glue line. If you accidentally go through it theres no recovering. If I am using a wood were grain match is critical I use this method.



When I have done this, I make (and leave) the largest diam. of the plug a bit larger than the diam of the hole, and I make little effort to match tapers. The plug, when glued up, will stand a bit proud of the surface of the vessel...so it can never, as you say, "go through." A little pressure from the tailstock when gluing will make a super-thin glue line, but this is a good thing, as it makes a more invisible joint.

Usually, the wall thickness at the base will be plenty thick, so, for instance, if the thickness is 1/2", and your tapered plug only contacts a half of that, 3/8" of glue is way enough.

I hope that you don't see this as "walking on" your thread.... I really like your piece, shown here, and I also hope that others can get an idea of how cranky redwood can be.

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## woodtickgreg (Jan 20, 2015)

Great post Scott! I found it a little late but enjoyed it just the same. A little jealous of your 2 lathes.Very cool that you showed that things do go wrong sometimes but that they can be fixed or as we put it, a design change. Awesome thread Scott.

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## NYWoodturner (Jan 20, 2015)

Mike Jones said:


> I hope that you don't see this as "walking on" your thread....



Not at all Mike! I think this kind of open dialogue and sharing of info and ideas is what these forums should be full of.

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## ironman123 (Jan 20, 2015)

Scott, that is a beauty and the whole post is very informative. Thank you.


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## gman2431 (Jan 20, 2015)

NYWoodturner said:


> Not at all Mike! I think this kind of open dialogue and sharing of info and ideas is what these forums should be full of.



I know it helps to inspire me!

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## Kevin (Jan 20, 2015)

I've bookmarked this thread. Now any time someone asks why I don't do HF's I can just refer them here. 

Great job Scott.

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## duncsuss (Jan 20, 2015)

Kevin said:


> I've bookmarked this thread. Now any time someone asks why I don't do HF's I can just refer them here.



LOL!

Thanks for putting together this build thread, Scott. I've tried a couple of times to take documentary photos as I've been going along, and always manage to forget that and turn way past the point where I should've taken another photo. (Reversing the lathe didn't seem to help.)

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## GeorgeS (Jan 21, 2015)

Very cool! That's some beautiful grain! I bet you were mad when that flute at the top broke but honestly I like it just as much without it.

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## MikeMD (Jan 22, 2015)

Great play by play. When I do HFs, I tend to do them in two parts (with the seam at the widest point...then hiding the seam with a bead or embellishment as you pointed out). Haven't done one from the bottom. Interesting way of going about it. Thanks for showing the process. Sorry it didn't quite work out as planned.

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## barry richardson (Jan 22, 2015)

This has been a great thread, lot's of good tips. I'm thinking this would work best with a dry blank though. But I rarely get my hands on a dry HF blank large enough for an HF, that's not all cracked to hell. A bit of a dilemma it seems. Soft wood tends to be more stable and dries better in bigger chunks, but not great for this technique, and hard woods are very rare to find in large dry blanks in good shape... What say you, Scott, Mike?


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## MikeMD (Jan 22, 2015)

I agree that it is hard to find large enough pieces that are already dry for HFs (when you want to only once turn them). I happen to have some pieces that I've had around for years and years. So, they'd work. I've also gotten some 4 x 4 x 48" and 5 x 5 x 48" sections from my sawyer of cherry and walnut. He uses them for stacking lumber (of all things). He had them around for 2-3 years. And I had them for 1-2, so those work well, too. Tough to find stuff larger that is dry all the way through...


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## woodintyuuu (Jan 22, 2015)

NYWoodturner said:


> Not at all Mike! I think this kind of open dialogue and sharing of info and ideas is what these forums should be full of.


nice thread an work

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## NYWoodturner (Jan 22, 2015)

@barry richardson Dry hardwood is definitely the way to go. It makes the process much easier (except for the hollowing part) and gets much cleaner results. If you find a very stable wood like mesquite in your area that was relatively dry it would have so little movement that you would likely have no problems. 
Here is one I did in Monkey Pod which is not as stable as Mesquite. The seam is located in the widest point like @MikeMD said. I could have never achieved this clean a line is something soft like redwood. I only chose redwood for speed purposes. I knew it would be a quick turn and hollow.

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## barry richardson (Jan 22, 2015)

Thanks Scott, the bottom method is what I plan to try one of these days. Mesquite would be a good candidate, gonna keep my eye out for a clean crack-free chunk...


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## MikeMD (Jan 22, 2015)

Though I've been able to get the grain to match up almost perfectly (and I mean seamless) with the seam being at the shoulder, the bottom line is that there is a glue joint going across the grain...which, no matter how good the grain match is, will show up. So, I've found that that glue line needs to be embellished so that it doesn't look like a 'cheat'. Beads seem to be the best way to hide it.

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## ripjack13 (Jan 22, 2015)

Scott...this is an eye opener. I need to try this. Looking forward to seeing it all shined up...
Very nice shape....

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