How do you guys spline a two piece rod?

You spline each section seperately. If the blank is heavy enough it may be difficult to find the spline on the butt section.

Just curious, ever have the spin come up differently on both halves??

The spine is where the spine is. If you spine a production rod you'll probably find the spine will vary from section to section and rod to rod and the guides will only be correct relative to the spine by accident

Jeff is correct and never trust the Manafactures Logos.
They claim they are on spine but about 70% of the time are off.

I was in a bind and was looking at off the rack smaller rods, not one rod that I checked out (about 10 of the Ugly Stick/Shimano variety) was correctly spined... Get what you pay for I guess...

Spining a rod after it is wrapped is not as easy as before. With the seat and guides on , slight pressure like you would use on an unwrapped rod may not show the true spine. However , when loaded well , as it would be fighting a fish , you'll feel the twist if its off. So anyway , my point is that if you are checking a factory rod to see if its buildright relative to the spine , give it a good bend and see where it settles . It may be different than if you just slightly flex it. Al Goldberg talked about it and I think he used terms like true spine and effective spine or apparent spine?

Actually, in many cases you DONT get what you pay for. Most factory rods, even from Loomis, St Croix, and other high end manufacturers are not properly splined. Its not a case of being slightly off, many are 90 degrees or more off spline. The Ben Doerr Elite rods, for example are typically not splined and have cheap Pacific Bay components. They cost as much if not more than custom rods from most shops with better hardware.

What exactly is splining? from the posts it sounds like finding the natural bend in the
the blank.

If you look inside the blank , you will see its nice and even walled around the circumference except at a spot which has a little bump. That bump runs all the way down the length like a spine. I think its where the fiber wraps start and end. Anyway , the blank is stiffer along this spine. If you you put the rod on rollers at the butt and tip end and press down in the middle , the blank will turn till the spine is on the outside of the bend or directly down if you flexed the rod directly down. You have to line up the guides and reel seat exactly along this spine or at 180 degrees to it (depending on what you are trying to optimize) or the blank will want to twist in your hand when it is loaded while you are fighting a fish. A blank that has the guides aligned at 90 degrees to the spine will twist a lot when loaded.This makes it uncomfortable to hang onto and tires your hands out.

The spline is not always visible though and other factors come into play when determining the fishability of a rod. Things like curves in the blank(often called a crook, as in shepard's) and different places where the compound taper will impact the balance of a rod - just like Saltheart says... If you've ever had a big fish loading up your rod and you feel the rod jumpy and you're reel trying to twist on you, good chance it's spined wrong...

this might explain why with some of my two peice rods go out of alignment when bringing in a fish.

I had a two piece Loomis surf rod that would constantly come out of alignment. A Loomis rep told me they would replace it under warranty. Before getting around to replacing it, I sold it and informed the guy of the defect and that he could have it replaced. Loomis sent him another top half for the rod. Brilliant