(Chuckling )
Well, you see, there’s a reason I know about this. I guess experience and progress isn’t through things that go right, it’s what ya learn from what goes wrong. And here’s how I know about routing plastic:
See, Haffs had this board, an old Midget Farrelly Stringerless or maybe it was a Hot Curl, a G&S anyhow. Thing is, it had a WaveSet fin.
Note I said ‘had’. Not ‘came with’. What it came with was about three inches of lexan Greenough Stage 4, snapped off. And that most definitely wasn’t enough to make that thing point in anything like the right direction, especially with Haffs on board, 'cos he wasn’t exactly the most highly skilled cat on a hot foam board, as it were.
Well, when Haffs and his ilk had board problems, they came to me. “Doc, can you…?” And I’d look, cuss, ask how in Hell’s hatrack they managed to do something like that and just how they thought I was gonna fix it. And then, well, I’d come up with something. That’s how I got ‘doc’ pinned on me. Or one of the reasons, anyways.
So I see this thing, this amputee Greenough fin. Oh gawd, as even then the fin system was extinct, ‘and how ya gonna do this, swifty’ I asked myself.
So I came up with a plan. Not solid glass, not wood, stay with the plastic. Labor on one of the other methods was gonna be substantial and did I mention that Haffs, being from old money, was about as tight as a duck’s butt in icewater? High Density Polyethylene plastic - HDPE as it’s known to its friends -they make commercial cutting boards out of it, among other things.
“Haffs”, I said, “get a nice, 1” thick industrial cutting board, at least 12" square". I figured he’d look for a bit, lose interest and my problem would be solved. Most restaurant cutting boards run about 1/2" and I had absolutely no idea where you’d get thicker stuff.
No…Such…Luck.
About two weeks later, he shows up with it. Okay, I’m busted, now I have to actually DO it.
Damn.
Cut the outline shape on the bandsaw. No problem.
Those boxes taper faintly, top to bottom, cut that on the tablesaw. No problem, albeit a little spooky, holding that tall chunk of plastic vertical against the fence.
But now to foil the thing. Tried a disc sander, 8" wheel on it.
Rut-roh. See, you have thermoplastics and thermosetting plastics. Thermosetting plastics, like PVC and polyurethane, they go from molten to molded to hardened and they don’t really melt again. They burn, and quite nicely, but they don’t melt.
Thermoplastics melt. And harden…or ‘freeze’. And melt again.
HDPE is a thermoplastic.
So, with the big sander, I just smeared the stuff around a little and gummed up a few discs before I decided that maybe I oughtta try another tool.
Well, what did I have that’d take away stock quickly? Hmmm - router? Sure. A short, straight, wide hinge mortising bit in it, 2 flute type, and off to the races I went.
And lets just say I was pipped at the post. Or broke down in the pace lap.
Fired up the router, had at it, and WHEEEEEEEEEEEEEEE. The bit may not have been the sharpest I had, and it didn’t cut all that wonderful. But melt HDPE? That it did. Whip it up besides? Ohh yeah. And after the bit had whirred on through, the stuff froze again.
HDPE meringue. I had invented a really, really bad open celled foam.
After I chipped off the foamy goodness with a hatchet, I did what I should have done in the first place, broke out files and rasps and surforms and did it by hand. Sanded it lightly at the end, drilled the appropriate holes, finish fitted it and there we were.
Pretty good fin too. Haffs was out surfing one day with a few of his cohorts. One was on a big, heavy, red lifeguard paddleboard. Haffs went a-steamin’ along, straight into the paddleboard. Now, those things were and are heavy. But the fin I made went in something like six inches into the rail. What ya might call your proof of concept testing.
I kinda rested on my laurels after that, at least in making WaveSet fins. Or, more accurately, I ran and hid when anybody brought the subject up. I still have that stump of a Greenough fin around someplace, kept it as a reference on the base shape of the WaveSets. Heaven knows why.
And…heh heh, evil old ________ chuckling again… now my good friend patrick gets stuck with just what I used to get. You’ll maybe recall from his 12’ blank post that he was swamped in ding repairs? He’s good, better than I ever was, which in many ways is its own punishment.
I think I owe him a few good beers, just 'cos I don’t have to do that anymore… or rout plastic, at least for fins.
doc…
