HF Question

[Mike A. Smith]

My much anticipated (well, by me anyway) HF is on the lathe and approaching completion. I'm trying to decide where I want to end up with the inside walls (other than smaller than the outside). I have already determined that double ended calipers will be purchased prior to my next effort. My single ended ones will not negotiate the curves through the small opening. The "top curve" is currently 1/4" because it "looked" right. It gets quite a bit thicker after the major curve going toward the base. But the inside follows the outside quite well and the only way you can tell is if you put your index finger in as far as you can and feel the outside with your thumb. So I'm pretty much the only one that's going to know.

The question:
How uniform do you personally try to get the wall thickness on a HF?

I know this is very subjective and the ultimate answer for my HF will be whatever pleases me. But I would like to see some discussion from the HF turners in the crowd.

[Paul Andrews]

Mike,

I try to make the walls a uniform thickness except at the bottom where I leave a little more to add weight for stability. To measure the wall thickness I use a 3/16 tin rod found at most hardware stores, and bend it into a circle leaving the desired wall thickness plus a 1/4' as the gap between the two ends. This will do a good job measuring around curves and should give you uniform thickness.

As for the finished thickness, it depends on the size and stability of the form. What looks right to you is a good measure.

[Bernie Weishapl]

It depends on how thick I want to finish the piece I am working one. I leave some thicker than others. But if I want a 3/16", 1/4", 3/8" wall I try to get that thickness from the bottom to the top. I have 2 double ended calipars with one being the large one and one small.

[Robert McGowen]

Hi Mike,

Not to get off track from your posted question, I would add that without some sort of thickness measuring capability, you run the real risk of making a nice bowl and a small funnel out of your hollow form. I have read numerous posts about "I was just taking the last little cut, when it exploded into two pieces." I would rather have a little thicker and very nice hollow form posting than have a "you won't believe this happened" posting. Good luck!

[TYLER WOOD]

Robert, has my mentor been telling stories on me again.

I did that wil a really really nice, first hollow form. I had it down to some pretty thin thickness. I stopped the lathe, felt the inside, noticed a ridge. Well I could either sand it out or, nah I'll hit it one last pass with the scraper. POOOF bowl and funnel. NOOOOOOOOO00000ooooo......

[Allen Neighbors]

I made a set of double-ended calipers from a discarded Stop sign, and try to get the thickness uniform except for the bottom, which I leave a little bit thicker for ballast, like Paul Andrews. I have a built-in, benign familial tremor, which makes it hard for me to be perfectly precise when hollowing with handheld tools, but I shoot for 1/4 to 3/16" most of the time.
I made a captured rig and fitted it with a Radio Shack Laser pen, and can now be more precise.
If your wood is not cured, the HF will fare better (be less prone to cracking) if the bottom is slightly thinner than the upper walls, but you can remedy that little problem by finishing the bottom with a concave center.

[Mike A. Smith]

...I would add that without some sort of thickness measuring capability, you run the real risk of making a nice bowl and a small funnel out of your hollow form...

Trust me, once I realize my single end calipers wouldn't get it you could see that realization in my eyes, the bead of sweat on my upper lip and immediate pucker factor added to the project. As stated, I will have a double-ended set before trying this again.

[Dennis Peacock]

Mike,

What type of setup are you using for hollowing??

[Mike A. Smith]

Mike,

What type of setup are you using for hollowing??

Bowl gouge, Sorby hollowing tool and tear drop scraper.