I'd written this up a while back, but was waiting to post it until I'd had a chance to dive with it a few times. But I was checking over at divematrix which I do occasionally, and someone had just asked about exactly this today, so I posted it there. In the interest if keeping the universe vaguely in sync ...
Executive Summary
Pop out the grey twist knob, put a piece of 1/8" bungee through the hole at the back tip with a knot inside, and snap the knob back in.
Introduction
After reading the suggestion by HBDiveGirl in the thread http://www.scubaboard.com/forums/technical-diving-specialties/322756-what-pencil-wetnotes.html I thought it sounded like what I wanted. I got a couple of these on eBay. The H lead, the hardest of the three available, is plenty soft enough IMO.
Looking it over I agree it's well suited to use with diving; no metal parts, small enough to stow but big enough to hold, thick robust lead, the point can be retracted for protection, and more lead is just a twist away, no sharpening needed. I'd recommend it for slates as well as wetnotes.
The only issue for me was how to put a leash on it; I don't like to dive with anything that's not tied to me, other than my buddy. The usual slate pencil approach of tubing or string attached to the butt end didn't look promising, since the back twist knob is only about 1/2" long, conical, and needs to turn in the pencil body to operate the pencil. And I didn't want to make the pencil any thicker.
Details and Pictures
This isn't rocket science and might be obvious to some, but it took me a bit of experimentation so I thought I'd document what I found works, and the Croquis construction. Others can duplicate it or modify it as they like, or based on this information, do something else entirely, including retaining the freedom to drop their pencil into the depths. This has the advantage of minimum added bulk, and I think it's robust.
The Croquis has 5 parts; the lead, the black body, the screw-on transparent tip, a nylon worm/lead holder, and the grey twist knob/worm follower. There's an axial hole in the back of the grey knob. I don't know that it has a functional reason for existing, I'd guess it's an artifact of manufacturing. It seems unlikely that it was intended to hold a leash, this is sold as an artist's sketch pencil. But it's just big enough to push 1/8" bungee through.
I was able to pop the grey twist knob out with a thumbnail, no tool needed, it's just a plastic-on-plastic snap-fit ridge. I'd suggest that before you do that you advance the lead out a half inch or so, so the worm is not all the way at the back.
Do not try to pull out the nylon worm/lead holder; it has to be unscrewed. The worm operates around a molded inner projection in the waist of the black pencil body; pull with enough force and you'll probably either break that off or break the worm, and the pencil would then be just a case for a spare lead. For purposes of adding the leash, the only disassembly required is popping off the grey twist knob. But if you want to play around with it, the nylon worm can be removed by unscrewing it.
My preference for the leash is 1/8" bungee. I get mine at REI. Nylon cave line would be easier but I don't like the way it tends to fray, snag on velcro, and entangle when used for leashes of any length on gear. And using bungee gives me the flexibility [ pun intended ] to make the leash just long enough; if I discover I need another inch or so in use, it can be stretched.
I threaded it through the hole, tied a really tight knot, cut the free end really short, then encapsulated the whole knot in a moderately thick coat of gel-type super glue. Nylon line could just be melted with a lighter into a blob that can't untie. My usual way to finish bungee knots is heatshrink tube, but that wouldn't fit in this case. Because the super glue was applied thicker than usual, I let it dry 24 hours before pulling it back inside the grey knob, and pushing the knot fully back with a small screwdriver. Seems solid enough.
Then line up the ridges in the grey knob/worm follower with the slots in the nylon worm, push it in, and snap it into place on the body. I found that the knot takes up enough space inside the twist knob that the worm can't go all the way back, so to retract the lead all the way, I had to cut off about 5/16" from the back of the lead. Yup, that's about 15% of the usable lead. That's the tradeoff I made. Maybe you can make a smaller knot or a different connection method, or leave the lead exposed to start with. I think you could cut the back 5/16" off the nylon worm instead of shortening the lead, but I chose not to mess with the design, and just gave up the bit of lead.
Also, the bungee doesn't rotate in the knob, so if I operate the pencil by twisting the knob (vice twisting the body) the bungee gets kinked a little, but that fixes itself as soon as I relax my grip.
Just for completeness, my attachment to the wetnotes: On mine there's a small bungee loop at the bottom of the spine for attaching a bolt snap or whatever, to attach the wetnotes to the diver. I tied a knot in that very close to the wetnote body. Then I have two Croquis leashed together at opposite ends of a length of bungee. Feed one through the stretched eye between the knot and the wetnotes, then knot that. Other solutions might better fit other applications.
Executive Summary
Pop out the grey twist knob, put a piece of 1/8" bungee through the hole at the back tip with a knot inside, and snap the knob back in.
Introduction
After reading the suggestion by HBDiveGirl in the thread http://www.scubaboard.com/forums/technical-diving-specialties/322756-what-pencil-wetnotes.html I thought it sounded like what I wanted. I got a couple of these on eBay. The H lead, the hardest of the three available, is plenty soft enough IMO.
Looking it over I agree it's well suited to use with diving; no metal parts, small enough to stow but big enough to hold, thick robust lead, the point can be retracted for protection, and more lead is just a twist away, no sharpening needed. I'd recommend it for slates as well as wetnotes.
The only issue for me was how to put a leash on it; I don't like to dive with anything that's not tied to me, other than my buddy. The usual slate pencil approach of tubing or string attached to the butt end didn't look promising, since the back twist knob is only about 1/2" long, conical, and needs to turn in the pencil body to operate the pencil. And I didn't want to make the pencil any thicker.
Details and Pictures
This isn't rocket science and might be obvious to some, but it took me a bit of experimentation so I thought I'd document what I found works, and the Croquis construction. Others can duplicate it or modify it as they like, or based on this information, do something else entirely, including retaining the freedom to drop their pencil into the depths. This has the advantage of minimum added bulk, and I think it's robust.
The Croquis has 5 parts; the lead, the black body, the screw-on transparent tip, a nylon worm/lead holder, and the grey twist knob/worm follower. There's an axial hole in the back of the grey knob. I don't know that it has a functional reason for existing, I'd guess it's an artifact of manufacturing. It seems unlikely that it was intended to hold a leash, this is sold as an artist's sketch pencil. But it's just big enough to push 1/8" bungee through.
I was able to pop the grey twist knob out with a thumbnail, no tool needed, it's just a plastic-on-plastic snap-fit ridge. I'd suggest that before you do that you advance the lead out a half inch or so, so the worm is not all the way at the back.
Do not try to pull out the nylon worm/lead holder; it has to be unscrewed. The worm operates around a molded inner projection in the waist of the black pencil body; pull with enough force and you'll probably either break that off or break the worm, and the pencil would then be just a case for a spare lead. For purposes of adding the leash, the only disassembly required is popping off the grey twist knob. But if you want to play around with it, the nylon worm can be removed by unscrewing it.
My preference for the leash is 1/8" bungee. I get mine at REI. Nylon cave line would be easier but I don't like the way it tends to fray, snag on velcro, and entangle when used for leashes of any length on gear. And using bungee gives me the flexibility [ pun intended ] to make the leash just long enough; if I discover I need another inch or so in use, it can be stretched.
I threaded it through the hole, tied a really tight knot, cut the free end really short, then encapsulated the whole knot in a moderately thick coat of gel-type super glue. Nylon line could just be melted with a lighter into a blob that can't untie. My usual way to finish bungee knots is heatshrink tube, but that wouldn't fit in this case. Because the super glue was applied thicker than usual, I let it dry 24 hours before pulling it back inside the grey knob, and pushing the knot fully back with a small screwdriver. Seems solid enough.
Then line up the ridges in the grey knob/worm follower with the slots in the nylon worm, push it in, and snap it into place on the body. I found that the knot takes up enough space inside the twist knob that the worm can't go all the way back, so to retract the lead all the way, I had to cut off about 5/16" from the back of the lead. Yup, that's about 15% of the usable lead. That's the tradeoff I made. Maybe you can make a smaller knot or a different connection method, or leave the lead exposed to start with. I think you could cut the back 5/16" off the nylon worm instead of shortening the lead, but I chose not to mess with the design, and just gave up the bit of lead.
Also, the bungee doesn't rotate in the knob, so if I operate the pencil by twisting the knob (vice twisting the body) the bungee gets kinked a little, but that fixes itself as soon as I relax my grip.
Just for completeness, my attachment to the wetnotes: On mine there's a small bungee loop at the bottom of the spine for attaching a bolt snap or whatever, to attach the wetnotes to the diver. I tied a knot in that very close to the wetnote body. Then I have two Croquis leashed together at opposite ends of a length of bungee. Feed one through the stretched eye between the knot and the wetnotes, then knot that. Other solutions might better fit other applications.
