So I’m having a bit of trouble feeling or noticing any definite jumps in my rod sections as I look for a spline. It’s an IM6 Rainshadow blank, 2pc., 6’6" rod, 2 wt. Any suggestions or advice? Thanks in advance!
I hope not to spark any debate about weather or not the spline is important, but if you cant find it I’d just assemble in the straightest orientation of the blank. I’ve had a few like that before that just seemed to not have any noticeable spline. I would guess that if it is that un-noticeable that you probably wont notice any difference if you line the guides on it anyway.
Yonks
I have had a few I have had to put a fair amount of pressure on to find the spine, but I have always found a spine. I have also swapped ends to the table with sections, too. Instead of supporting the tip end in your hand with the butt end on the table, turn it around. It seems to help on some of the tough ones.
+1
If you can’t find it, it won’t matter. Build on the straightest axis if you don’t do that already. I’ll pass on the spline debate as well. I think we’ve been over that enough. 
JC always said to line it up as straight as possible and go for it!
Did learn another kewl trick for spline finding. Take the end and set it on your shoe, hold the tip with your finger tip, and slightly push straight down. The spline will bow out.
Spline/spine found. It took a little more pressure and a hard surface to rest the section on but I found two fairly distinct “jumps” so thank you all for your help in this matter. Now epoxy on the other hand… People who have a hard time coloring in-between the lines probably shouldn’t engage in the use of epoxy without the use of copious layers of newspaper and a level 10 Hazmat suit!
Personally, I think that Dale Clemens confused the spine-finding issue in his Advanced Custom Rod Building. What you are really doing is finding out the natural way the blank would bend (what position it would twist to might be a better way to put it) if line was strung through the guides and the rod arched severely. I think you would be better off if you forget about looking for subtle “jumps” and just be concerned with placing the guides on the softest side of the blank. That would be the top side when arching a blank on a flat surface while applying downward pressure near its center; or you could say the inner surface of the arch.