Backyard Speargun Test Tank

Hi Y'all,

I got tired of waiting for the vis at my dock to get good enough to do some testing on my Dirty Water Rollergun, so I made a "test tank" instead. I tried to keep the cost down since it is really a means to an end (testing spearguns) rather than the end itself. It's not elegant by any means, but since I was after function, beauty was secondary. The shooting end can be seen from the street, and it's got the neighborhood walkers and security wondering what the hell the crazy guy is up to now. I love it! :laughing3::laughing3:

The tank is made up of 3- 8 foot sections that are 16"high by 16" wide. Those dimensions were chosen so I could get a section out of a 4' x 8' piece of OSB. I had 3 pieces of OSB that I had been kicking around the shop for years, so that's what I used. I used 2 x 4's and 2 x 2's for framing the bottom and sides for support.

I tried waterproofing the OSB with elastomeric paint (used to waterproof stucco) but that didn't seal the holes in the OSB, so I ended up using liquid rubber (used on roofs). That did it. A clear 1/4" piece of lexan and some "cabinet gloves" rounded out the ensemble. I had to use liquid tape to seal the gloves, but they still leak like a sieve, so I'll need to go to plan "B" on the gloves. They work good enough to try the tank, however, so I'll revise the gloves later.

The target is a 16" high x 16" wide x 12" thick foam archery target that is clamped down with bar clamps to keep it from floating (Hey, I said it wasn't elegant!).

So, with the neighbors furiously reviewing the neighborhood covenants, and my beloved wife of 42 years muttering under her breath, I commissioned the test tank today. Here are some pics of the tank. Results of the testing will be posted in the "Dirty Water Rollergun" thread as I go along. If anyone would like more info on how it is made, cost, etc, let me know and I'll be happy to oblige.

I'll try to get some more meaningful shots tomorrow.

Quote from Tin Man

I know that look. It's very rewarding :laughing:

Outstanding project. But we can't have you undoing years of drunken speculation by recklessly throwing data around . . .

How about an additional small window in one side, that would allow filming the muzzle reaction during the shot?

Of course, we could always replace drunken speculation with drunken testing- just to maintain the same level of credibility.

I don't have a high speed camera..... yet!

Total length is 24'. The look on the neighbors faces is hard to discern.... fear, concern, confusion? :laughing3:

Look what I built you, honey! It's a lap pool for koi! I love it. :laughing3::laughing3:

Ok, Jeff, you knew it would be just a matter of time. Does anyone have any info to get me started looking for a high speed video camera? I don't know the first thing about what frames per second I might need, or whatever else might be important. My sense is price will go up with speed, but what speed would I need to track a spear shaft, and what resolution would I need to get clear enough video to be able to analyze? I'd appreciate any info anyone might have. I tried the search but didn't come up with anything.:confused2:

There are some cameras out there that will shoot at 1000fps, and are moderately priced. Problem is that at 1000fps the definition is at something like 240 x 240, so you need pretty good light, amd things are probably kind of blurry if you blow them up in size. Hopefully there are some spearos who are shooting high speed video now and can share what they are using. With all the stuff out there on u-tube, you just gotta know there are moderately priced cameras that will work for videoing a muzzle or tracking a spearshaft. It's just a matter of finding the right camera the first try.