I recently watched a YouTube video of a guy testing arrows for static spine in a water bath. He put a few inches of water in a tub and added some soap to it. I'm guessing dish soap to help the arrow spin easier. He then put a plastic nock in both ends of the bare shaft and floated it in the water. He gave the shaft a little 'bump' and it spun to the heavy side down which is, theoretically, the spine stiff side. He repeated this a couple more times and the shaft spun to the same position each time. This looked very simple and makes sense to me. However, I'm curious to see how accurate this really is against shafts that have been marked out on an actual spine tester. I have shafts I'm going to check this way but none of them have been spine tested and marked already.
If any of you have shafts that came marked for spine for you, will you please check the water bath method and report back if you get the same reading. If it's the same this will be a great way for us to index our own shafts quickly and easily....and the price is right!
I'll be doing mine regardless, but it'd be nice to know the actual precision of the bath method.