I have just started building a 3pc 10ft blank and having a bit of trouble figuring out where the spine on this particular rod is.I don't have a spine finder or anything so I have been simply using the hand/flat surface method.

I've spined numerous other blanks and never had a problem but this one seems to not want to cooperate.When I roll it,it has 2 destictive ridges or spots where the blank wants to "jump" from the surface.These 2 spots are almost exactly opposite each other.

Also,the sections in between these 2 marks(where the blank jumps) are the sides that the blank wants to seek out and bend more naturally.The problem is,they both seem to bend the same amount,or similar enough that I can't seem to determine the dominant one(the one that the blank most wants to bend into).So what I have is a blank with 2 sides that feel the same opposite from each other and that goes for both the amount the blank wants to jump and the position of least resistance.

On top of that,I believe these blanks are supposed to be spined from the factory and they are marked with a pen at each end of each section is.The marks though are directly ON one of the areas of the blank that "jumps" and not on the outer side of the blank when in the most desired curved position,so I don't know if the marks are actually on the spine or not.

I know that in some books the spine is described as being where the blank "jumps",while others,like here on the FAQ section describe it as the outer side of the curve "where the blank wants to stay put",so I'm not sure if the blank maker marks the spine the way I normally do(like the FAQ section describes) or not.I always spince the blank to make sure anyways,but this one is causing me a few problems.

Does anyone have any suggestions?

The blank is a Dan Craft SIG V 3pc 10ft 7wt and I have 2 of these.I also have a 8ft9 4wt SIG V and 9ft 5wt SIG V and all 4 blanks are marked where the blank "jumps" rather than being marked on the outside of the curve where the rod wants to come to rest.Any input would be appreciated as I don't have a spine finder and I'm a bit paranoid of putting too much pressure on these blanks to spine them by hand as they are described as be fairly thin walled.

Thanks.

Sounds as if your blank has a double spine. The mark on the blank is just a reference point for a rodbuilder to use, not necessarily a guide for guide placement. I'm reading into your post that you just have reservations about putting the guides 90 degrees (or so) from the mark on the blank. No need to worry about that. I would disregard the mark and put the guides where your instinct tells you to. Hope this helps.

The effective spine will be where, under pressure, the blank rolls and comes to rest. Not where it jumps or kicks. Find that spot where it wants to stay put - where it doesn't jump or kick, and you've found the spine. The outside of that curve is where we place a reference mark. If you locate more than one area, look for the one where the blank locks in the best - where it seems the very most stable.

I suspect you're having the most difficulty on the short, stiff, butt section. Check the FAQs page on info on how to handle that one.

Many blank manufacturers mark the straightest axis, not necessarily the spine. You may wish to ask the maker where they normally mark their's.

...........

Have you asked Dan? He is always helpful and often responds on this board. If you tag your question "Question for Dan Craft" I'm sure he'll respond. I think this is better than calling him direct, because this way we can all benefit from his knowledge!

Thanks everyone.I've emailed Dan and hopefully will get some insight as to what the marks represent.If he doesn't post the info here,I will.

Thanks again Tom for clarifying what I was trying to say and for bringing up the "straightest axis" comment.That could very well be what the marks are.Usually when I've rolled a blank I've always noticed a definite path it wants to take into a bend and it is usually pretty easy to find,but this blank is definitely a bit tougher(for me).

The blank does want to jump in 2 spots and they are almost exactly opposite each other.The blank also wants to bend 90 degrees opposite these marks into it's natural curve and I know that the outside of one of them is the spine.I just need to figure out which is the more dominant one of the two because they seem very similar(at least to my touch).Usually one curve is more obviously dominant than the other but this one has 2 sides that are very similar.

Tom,you mentioned "If you locate more than one area,look for the one where the blank locks in the best- where it seems the very most stable".

This definitely makes sense and is what I have been trying to do.The blank seems to be comfortable rolling into both sides but I'm obviously not "feeling" things right.Will try again.The butt section is definitely proving to be a bit of a challenge,especially since I forgot to check the spine on that section before gluing on the fighting butt.LOL.

I guess if both sides are almost exactly opposite each other,and I place the guides on one of them,I am either going to be on or opposite the spine right?LOL.At least I've narrowed it down a bit.LOL.

Thanks everyone.