Going to try my first hollow form, any tips?

[Bill Wyko]

Its a piece of spalted maple about 4-1/2 inches tall and 6 inches round. Any tips before I ruin this beautiful piece of wood?:D I hope it looks 1/2 as good as Jims piece.

[Jim Becker]

End-grain or faceplate orientation? (I prefer the former for hollow forms as the scraper tools generally used for this work better in end-grain)

[Bill Wyko]

Im not sure. The spalting is very random on this piece. It's also coated in wax. I drum sanded the wax off the top and bottom but it's still hard to tell.:(

[Jim Young]

Go slow and don't be in a hurry to hog away the wood. Keep the tip above center.

[Dario Octaviano]

How do you clear the shavings from those really tiny holes???

I am thinking of making a hose adaptor and sucking them with my DC but not sure if that is how it is supposed to be done.

[Travis Stinson]

I use a nozzle with my air compressor Dario. It can get pretty messy :( , but it does a good job of clearing everything out.

[Jim Becker]

In addition to compressed air...or frankly blowing through a little tubing...you can make a little "clean out scoop" from a piece of #10 copper wire. Hammer a half inch or so of the end somewhat flat and put an almost 90º bend in it about 1/4" to 1/2" farther down. Use some sand paper to get rid of any rough edges. You can use this to help "motivate" the chips to come loose, especially if they are a little impacted 'cause you didn't stop soon enough. David Ellsworth demonstrated this little tool in his three-day class.

One other thing...learn to "measure with your fingers". Yes, you can use calipers, but it's good to learn the feel of thickness to compliment the tools. Go slow, check often and take gentle, shallow cuts as you are working out to the final diameter.

Speaking of which, unless it's a very small piece, you want to work in stages/steps to avoid instability from vibration. Hollow out a bit of the center and then work your way out to almost finished thickness. Do another layer starting at the middle. Make some finishing cuts up high and try not to revisit this area again unless absolutely necessary...and if you do...be gentle. Repeat until you reach your final depth and interior dimensions.

[Bill Wyko]

Man is this thing a PITA! the spalted maple was much softer in some places than others. I'd get the outside round then start sanding and it would turn into an egg. Once I got it round for the 3rd time I just very lightly let the sandpaper touch the piece. It still has some small pits from the end grain. I see some people have posted different ways to solve this but I'm a little unclear as to which is the ideal way to solve this problem. I haven't hollowed it out let. Do you typically sand the inside very smooth or do you get it close and black it out? For me, segmenting is much easier. You guys that do this hollow forming, my hats off to you! Thats a real talent.:D

[Neal Addy]

I always sand and finish the inside of my hollow forms but only because the hole is usually big enough to get a finger in.

My biggest problem with hollow forms is turning the inside bigger than the outside. I hate when that happens!

[Bill Wyko]

I like to refer to that as a transparency turning.:eek:

[George Tokarev]

How do you clear the shavings from those really tiny holes???

I am thinking of making a hose adaptor and sucking them with my DC but not sure if that is how it is supposed to be done.

If you do the primary hollowing with a gouge, you can tilt the handle down a bit and roll the shavings down the flute and out. I like to do as much with the gouge as possible before going to something prone to clogging and jamming like a ring or scraper.

Shanking down on the DC is going to be less than effective. They work on volume, not vacuum. Some flexible tubing of suitable diameter inserted into the hole is better. Lung power is all you need, but I do recommend a bend in the tube to keep your face out of the stream. Do not cough and inhale when doing this.:D

[Jim Ketron]

I think you need to start out on some more forgiving wood until you get the hang of hollowing. Anything that is spalted is going to have softer areas and this can be a problem for semi closed forms on getting a good clean tearout free surface inside where sanding is going to be much harder to do. One option is to sand as best you can and then use a collar with a smaller opening to keep fingers and eyes from poking around inside, or make the opening big enough to make for easy sanding. There are a few tricks to stiffen up the torn fibers and do a few final passes to help reduce the sanding chore. I have used a hardening oil like Watco inside the form let it soak in good then make a few lite final passes with a scraper if that will not work I soak it again and let it dry then make a few more lite scraping passes.
As for power sanding spalted or punky wood I turn up the speed from what I normally sand at. The heat build up on softer wood is less than harder wood and it will help keep the shape in tact without sanding away too much wood in one spot buy going at lower speeds.

[Bill Wyko]

Thanks Jim, That higher speed sanding did a nice job on the outside. I still didn't do so good inside but it was practice. I found that piece to be the most difficult so far. I'll post a pic tomorrow.

[Tony Kent]

Hello,
I too will be trying an HF soon so have been very interested in this post. As for the spalted maple, please be careful sanding it etc since spalting is mold or so I have read. Evan if you are not allergic to mold it could cause you problems. I say all this because I now have to stay away from spalting woods as well as some of the exotic woods too, like cocobolo. Sadly I can't seem to use myrtle wood either:( Happily though there are other woods to turn.
Take care, have fun and be safe.