I've begun building a new rod (a Sage VT2 3 weight 7' 9" blank). I built a rod about 14 years ago, so I remember a lot of the basics, but forgot some things. I've been able to refresh my memory on most things from the web, and it seems I've lost my books I relied on building the first rod. I'm about to mount the reel seat, and forgot (and can't find any clear info on the web so far) if I need to mount it with the butt cap tight against the butt of the blank, or if I can leave a bit of room in between the two.
Thanks for any tips.
Andy

Andy,
You can mount the reel seat how ever you want to mount the reel seat.
If you want to install a butt cap on your rod, the only requirement is that you have a way to install and get the butt cap to stay on the rod.

If this means having the end of the handle flush with the blank, do it like that. If it means having some space between the end of the blank and butt cap, do it like that.

Often when building a rod, it sometimes works better to let the handle extend past the end of the blank. Then, use a disk sander to sand the end of the handle flush with the blank to apply the butt cap. This often gives a nicer overall finished look to the handle.

If you happen to have a butt cap that needs a tenon (undercut)http://en.wikipedia.org/wiki/Mortise_and_tenon)) (( at the end of the handle, and if you have a preshaped handle with the tenon already cut into the handle, then the logical way to install the handle is to do it with the handle flush to the end of the blank. When you do, be sure to clean up any excess glue to avoid a later problem in applying the butt cap.

Many things about rod building are simply common sense and can often be done in a multitude of different ways that all get the job done. Then, it is up to you as the rod builder to use the particular system or method that makes sense to you, and the system that works well for your particular skill, and tool set.

Rod building should be an enjoyable and interesting job. When any type gluing and or other assembly work is involved - carefully thing through the entire process, do dry fits of all parts, and do any tweaks, alignments, or trimming, before applying the glue.

You can dry fit parts many many different times, and in different ways as long as y ou don't apply glue. Get it right before any glue is applied. Then, when the time for assembly comes, all of the parts will fit together like a glove and you will have the final finished appearance that you really want for your particular job.

Take care
Roger

Dry fit the reel seat - as many fly rod seat butts set inside the tube of the reel seat slightly (1/8 of an inch or so).

Either method will work. I mount them flush. Do what you feel is best for you. The glue bond is what matters most.