New milestones

I have some new recent milestones to note.

First, last Monday, I drove solo for the first time since my accident. The weekend before, I practiced driving in a big empty parking lot and on the empty streets of an industrial park. I managed to park and corner and not run Karen over, so she granted me permission to drive myself to the dentist. I am using extra caution—my left-side blind spot really is a blind spot at the moment—but feel pretty good about being back on the road. I won’t be driving a lot or at night anytime soon, because I am not seeing well in low light and am not adjusting quickly to changes in light, as with oncoming and passing headlights, but it is good to know that I am not entirely dependent on others to get around.

Thursday, I finally finished the vessel I was working on when I had my accident. I epoxied it back together and filled the exterior cracks with turquoise inlay. It is now lucky number 13 in the commissioned series.

The vessel that broke and hit me, now repaired and finished.

The vessel that broke and hit me, now repaired and finished.

Another view of the vessel. I like that these sapwood patches look like eyes--and the left one (on the right in the photo) matches mine at the moment!

Another view of the vessel. I like that these sapwood patches look like eyes–and the left one (on the right in the photo) matches mine at the moment!

 

And on Monday, I started the first of the last four vessels in the series—from another highly cracked log. I used the wire guard on my lathe and wore my riot helmet for protection. The wire guard does interfere with seeing the curve I am cutting, so I probably will not use it for the final external shaping, but I will continue to use it for the rough turning of these vessels and while I hollow the interiors. I am pleased with the riot helmet. It is not too heavy. My head got a little sweaty, but that’s not a big deal for me.

Oh, and today, I used my chainsaw.

Finally, it appears that I will pass a major milestone at the end of February: Dr. Harris says the silicone oil in my eye can come out. She will perform another laser procedure next Tuesday just to make sure my retina is securely tacked down, and three weeks after that, she says, I can have the surgery. I was expecting to have to wait six months from the October surgery, but she says I am ready, or will be (it will be four and a half months by the time the surgery happens). My understanding is that she will replace the silicone oil with saline. I am hoping that this will improve my vision. When you compare photos of the retina in each of my eyes, the right is sharp and the left is dim and blurry, because of the oil. I still won’t have a lens, but I hope that what I can see will be a little clearer and brighter without the oil. And after I heal from that surgery, I can be measured accurately for a new lens, so maybe that will happen sooner than expected too. I don’t want to rush—I want to give my eye all the time it needs to heal as much as it can—but I am anxious to see better.

Safety gear

For safety, I use the Uvex Bionic face shield, which I bought from the Sanding Glove, and a small 3M 7500-series half-mask respirator with P100 filters (other half-mask respirators did not come small enough to fit my face properly—true for most women, I think). Even though I wasn’t wearing my face shield at the time, since my accident, I have looked into whether I could improve that protection. (I also wanted to find out how much protection my face shield would have provided.)

One of the possibilities I considered was the Trend Airshield Pro, which is very popular among woodturners. I discovered, however, that it claims to meet only the “low energy impact” standard for eye protection (http://www.trendairshield.com/specifications.html) and its stated respiratory protection is also lower than what I already have (and it is not NIOSH approved).

The safety standard for eyeglasses and face shields is specified in ANSI Z87.1-2010, which includes general specifications and impact specifications. It is the general specifications that the Trend Airshield Pro meets. My Bionic face shield is rated for the high-impact Z87.1 specifications.

I did the math (see below) and realized that, measured in kinetic energy, the mesquite missile that hit me delivered about 30 times the amount derived from the high-impact Z87.1 specs. Surely, my face shield would have absorbed some of that energy, but I almost certainly would have been injured anyway. Polycarbonate isn’t supposed to break or shatter, but all that energy would have had to go somewhere. Could I have escaped with bruising and a concussion? Would my face bones still have broken? Would the impact have contacted my eye? Does anyone have any experience they can share?

Anyway, I went further with my research and looked into ballistic face shields. These are expensive and heavy and seem to me like overkill (they are also not readily available to civilians). But they did lead me to riot helmets and face shields, regulated under the NIJ 0104.02 standard, with about 15 to 27 times the impact resistance specified under ANSI Z87.1. I ended up buying the lightest one I could find, the Max Pro RD1002X; it weighs 2 lb 3 oz, just a little more than the Trend Airshield Pro. Others weigh 3 lb or more, which I thought might be a bit heavy for prolonged wearing. I should receive it in a week and will report on how it feels.

Max Pro RD1002X anti-riot helmet

Max Pro RD1002X anti-riot helmet

You may notice that the impact resistance of the riot helmet is still not equal to the impact I sustained in my accident; at best, it is 15% too low. I balanced the impact resistance against potential comfort (weight) and cost and also reasoned that damage to this helmet would still mean considerably reduced damage to me.

My intention is to wear my Bionic face shield with my respirator when turning most things (most of what I turn is small and light), but to wear the Max Pro with my respirator when turning heavier pieces, especially when working with cracked wood. I also installed the wire guard that came with my Jet 1642 lathe and will see how that feels. I have read that others don’t like using it, but I’ll try it to see if it interferes with visibility or tool use.

The wire guard on the Jet 1642 lathe.

The wire guard on the Jet 1642 lathe.

For the technically minded among you, below is a summary of the kinetic energy figures derived from the specifications and my calculations. I give the foot-pound equivalents for kinetic energy for those more familiar with the units used in ballistic specs.

KE Unit Accident Z87.1 High Velocity Z87.1 Penetration 0104.02 Impact 0104.02 Penetration
Joules 127 4 6 111 88
Ft-lb 94 3 5 82 65

Formulas:

  • velocity of falling object = √(2 × height from which dropped × acceleration due to gravity)
  • kinetic energy = .5 × mass × velocity²

My accident:

  • 1-kg piece from a 10″- (.254 m–) diameter vessel turning at 1200 rpm
  • velocity = (.254 × 3.14 (pi) × 1200) / 60 sec = 15.95 m/sec
  • 1 kg traveling @ 15.95 m/sec
  • .5 × 1 × 15.95² = 127.201 joules (93.82 ft-lb)

ANSI Z87.1 tests (Bionic face shield):

    High velocity:

  • ¼-inch steel ball (.001046 kg) traveling @ 300 ft/sec (91.44 m/sec)
  • .5 × .001046 × 91.44² = 4.373 joules (3.23 ft-lb)
    High mass impact:

  • 500 gm (0.5 kg) pointed projectile dropped from 50 inches (1.27 m)
  • velocity = √(2 × 1.27 × 9.81) = 4.99 m/sec
  • .5 × .5 × 4.99² = 6.225 joules (4.59 ft-lb)

NIJ 0104.02 tests (riot helmet):

    Impact:

  • 5.1 kg traveling @ 6.6 m/sec
  • .5 × 5.1 × 6.6² = 111.078 joules (81.93 ft-lb)
    Penetration (pointed striker):

  • 3 kg dropped from 3.00 m
  • velocity = √(2 × 3 × 9.81) = 7.67 m/sec
  • .5 × 3 × 7.67² = 88.243 joules (65.08 ft-lb)

This is a simplification, of course. The numbers don’t take into account air resistance, drag, pressure, or other factors. They just gives me a means of meaningful comparison.

Addendum

Australia and New Zealand have higher impact standards. (Their medium impact standard is close to the ANSI Z87.1 impact standard—at least for eyeglasses. Cannot find their face shield specs.) Their test for high velocity uses a 6.35-mm (¼-inch) steel ball traveling at 120 m/sec. This yields a kinetic energy figure of about 7.5 joules, compared to 4 joules under Z87.1. The Triton Powered Respirator meets this higher standard, and its shield is indeed thicker than that of the Bionic face shield. I did not check the helmet or respiratory standards for this device.

Oops! The Triton respirator may no longer be available: I can’t find it even on the Triton web site.

Preparing for a show

I have a major show coming up in just a bit over three weeks, so I’m trying to get in gear and get productive. This is just one of the business aspects of trying to make a living as an artist. It requires a different mindset than simply creating what is in my heart. Unlike many woodturners, I don’t have a production line, which means I don’t make the same item or type of item over and over. I do have to consider the marketplace, however, and make sure that when I do a show, I have available a wide range of vessels, in terms of price, size, shape, style, etc.—mostly so that I can offer customers choices, but also because variety makes for a more-inviting display.

Variety also, of course, keeps the creative process fresh for me. Even when I am focused on producing a lot of work efficiently, I still want every vessel to be uniquely itself. I want the process to remain one of creation, not one of mass production.

The upcoming show also means that I need to put off solving some equipment problems I’ve been having—chiefly with my chucks. The spindle on my old lathe was 1 inch; that on my new lathe is 1¼ inches, which meant that I had to change the insert on my old Teknatool Supernova chuck. The insert had seized, however, and in removing it, I appear to have damaged a jaw slide, as the slides no longer meet snugly at the center (and jaws don’t close properly either). The damage isn’t readily identifiable, however, and I’ve already spent one afternoon trying to pinpoint the problem. That chuck used to be perfectly centered, with perfect repeatability when I would remove and replace pieces. My new chuck, a Supernova 2, isn’t perfect, but I can’t spare the time right now to tweak it either. I’ll let you know what I figure out when I finally have time, after the show. In the meantime, I just have to make do. To quote Tim Gunn, “Make it work!”

Studio shots

I’m gradually getting settled with my new lathe in my still-newish studio digs, but here are some pictures, finally.

My new lathe, a 2-hp, 230-v Jet 1642.

I plan to install pegboard on the divider behind my lathe for easy tool access.

My work bench.

I’m still finding places for many things. In the meantime they clutter my work bench. Notice the handy space for wood storage below my bench.

My work space and Pat's.

You can see the lathe (a 1.5-hp Delta) and work space of the studio’s owner and my shop mate, Pat Reddemann, in the background.

Both my lathes.

Right now, my old lathe abuts the new one. The plan is to set up my vacuum chuck on the old lathe for both Pat and I to use whenever, without having to change the setup on our primary lathes. We will probably find a new spot for my old lathe soon, so I’ll have more working room at the end of my new lathe.

Pat's bandsaw.

Pat got this new 18″ Grizzly bandsaw just a couple of months ago and has already gone through several blades.

My tool chest and storage area.

This storage area and my tool chest area to my right as I face my lathe. The cabinet is full of wood. The shelves hold mostly half-finished pieces and finishes and solvents.

Our joint woodpile.

Pat and I share larger logs we’ve harvested together: a lot of mesquite, but also some African sumac and pepper tree.

My woodpile.

Under the tarp is yet more of the wood I’ve harvested from locally felled trees, mostly mesquite.