Ok......I haven't totally lost my mind, yet. And this isn't my first build either. But I swear, when I roll this blank between my palms, it 'pops' TWICE! I know it's 'popping' twice because I can see the strip of tape at the butt. How is that possible. Does it have more than one spine? The blank is American Tackle AMMBC843 Green Matrix. It's 84 inches. I'm going to make it into a casting rod. In fact I used the same model blank a few years ago for a build and there was only one spine/pop. What's up and what can I do?

Yes it can have two spines. As the prepeg flag is wrapped on a spiral it often results in two places that are stiffer than the rest of the blank. Many rod builders ( I'm included) ignore any spine and wrap guides on the straightest axis.

I'm just a hobby builder but in the last 25-30 rods I've built I haven't even checked for spine. Just put the guides on the straightest axis. I promise it will fish fine.

There are at least 6 or 7 manufacturing anomalies that create the spine effect (rod spine isn't a physical thing - it's an effect).

Most build on the straightest axis as spine has nothing to do with rod twist nor casting accuracy, but if you wish to find the spine and build on it, you can simply choose the axis which exhibits the strongest effect.

..............

I feel that the spineing of a rod was probably more critical when using the old fiberglass blanks. With all the new technology on creating todays blanks. I think it has basically gone by the wayside. I do spine some that show a prominent side, but the majority are not . I feel it is totally up to the builder on what they prefer. Thus said, if you want to, do it, if not, don't.

Spine, shlime. Build on the straight axis. If all things are equal, go with your gut.

I've been spining golf club shafts for twenty years. There may be no relationship between spine alignment and fishing rod performance, but don't tell a PGA pro that there is no relationship between spine alignment and golf club performance.

It also may be the reinforcement they put on the butt section, the graphite/aluminum twill material or whatever it is called. That may have it's own spine.

I've gone back and forth with spine. Used to check the spine, then got away from it, now I do a quick spine check on some rods and still haven't noticed a difference in fishing spine vs off spine.

A golf club and a fishing rod are not the same thing nor do they perform the same function.

.............

Next time I get a new blank I will try to hit a golf ball 250 yards LOL

Bill - willierods.com

I'd rather see how far you can cast that golf club

Please explain , how do you find the straight axis? I've been trying to find the spine on my rod blank, i think also mine has 2 spines, lol! kind of frustrating, I would like to know about the staight axis thing, sounds a lot easier! Thank You!