Smashing PVC

From Moondragon
Jump to: navigation, search

By Tivar Moondragon

This is a description of some tests on the durability of PVC plumbing pipe, in relation to how well it would work as an SCA rapier scabbard used for parrying.

Test #1 Plain PVC, at fairly high temperatures (mid-80s at a guess.)

I took a foot-long piece of 1/2" PVC pipe, clamped it into the vise on my workbench and tried whacking it with a wallhanger sword I just happened to have lying around. This blade is heavier and stiffer than any SCA rapier blade, and the edge is a bit sharper. On several attempts, all hitting it much harder than I would hit anyone on the rapier field--probably as hard or harder than I'd hit someone on the rattan field--I managed to crease and dent the PVC, but it showed no signs of breaking. Doing a similar-force blow on a piece of 2x4, the blade penetrated about 1/8" going across the grain of the wood and split a six-inch board completely when struck on the end.

The following morning, when the garage was ten or fifteen degrees cooler, I broke a room-temperature piece on the first hit. (Note that this was an older piece, so it may have photo-degraded to a greater extent.)


Test #2 Plain PVC, left in a freezer at 0 degrees for a couple of hours.

The first hit with the wallhanger shattered the PVC. One of the two larger pieces had a point that I wouldn't want coming at me at speed, even if I was wearing rapier armor.


Test #3 PVC with a single layer of duct tape over it. Three pieces, one left in the refrigerator (~40 degrees) one left in the inside freezer (~30 degrees) and one in the chest freezer (~0 degrees) overnight.

The three pieces I wrapped with a single layer of duct tape and put in the fridge, and both freezers last night all broke on the first hit, and the duct tape didn't do much to protect them.


Test #4 PVC with a spiral-wrapped double layer of fiber tape and a spiral-wrapped single layer of duct tape. One at garage temperature (morning, so around 75 degrees) one each put into the fridge and both freezers overnight. I also taped up a remnant of the older (and possibly photo-degraded) piece from Test #3 and left it at room temperature.

Hitting them with the wallhanger sword, all five pieces survived, with nothing beyond damage to the tape surface.


Conclusions:

1. Plain PVC pipe does seem to be rather fragile at cooler temperatures or if it's been out in the sun long enough to photo-degrade (and no, I don't know how long that would take.) While I doubt people would be doing too much fighting if it's below freezing outside, fighting at refrigerator temperatures--i.e. 30-45 degrees--is a distinct possibility (I've been to a number of tournaments where it's been that cold.)

2. Wrapping the PVC in a couple of layers of strapping tape with a layer of duct tape over it for cosmetic purposes does seem to protect the pipe quite a bit. I speculate that covering the PVC in leather would have a similar effect, or if it did break, the leather would contain the fragments, rather than letting them fly off into the crowd.

3. Mandating that scabbards intended for combat use be covered in leather or fiber tape is probably a good idea.


Commentary:

While talking about this experiment at fighter practice, one of the other fighters showed me his scabbard, which is made from the polyethylene tubing used for sprinkler systems. This stuff is much more flexible and less likely to break. Another possibility would be CPVC pipe (the grey stuff, not the white) which, I'm told, is stronger that regular PVC. I didn't have any samples available, so I couldn't test this, though.