I am going to build a couple of spinning rods for my children. I am thinking of using Batson E-glass blanks, cut down from 6' to 4'.
What is the best way to cut a fiberglass blank?
Is 4' a good length for 4 and 5 year olds?
What's the formula for estimating rod diameter at different points along the blank?
Any advice?
Thank you.

Cut them from the butt - i.e., cut 2' off the butt. This will preserve the action of the rod. Actually, I'd have started with a 5' blank and left it at that length - perfect panfish rod, if you get the lightest-line and lure spec you can find. You want a little "wand" for them so they can feel the bluegill and bream @#$%& on their worms, or so they can feel the fish fight after they hook them under a bobber. 5' is a better length, I think. I built several for my daughter at that age and they enabled her to get the tip well out of the boat or well over the shore. Shorter rods also limit casting (well, throwing, anyway).

We use a mini-chop saw with a carbide cutting wheel. One chop, no splintering, perfectly square cut.

I have no idea what you mean by "estimating rod diameter at different points along the blank. What are you trying to do ? You don't need to estimate anything - just take a caliper to the blank at any given point. Or, were you tring to figure out the size for a blank you haven't ordered yet - in which case, you need to go back to what I said above - just get them the lightest stick you can find.

Uncle Russ
Calico Creek Rods

Yeah, I wasn't very clear. I haven't ordered the blanks yet. I was trying to figure out what diameters I would be working with, if I cut some of the butt off, but, I think I'll take another look at my choice of blank length. Thanks, Russ!

I agree 100% with Russ. I build a lot for small children. 5 ft is the perfect length for any child to learn casting and fighting fish. Remember they are going to grow up and anything less will become too small real soon. If you make them 5 ft or even 5' 6" they will have a rod that can be used for years to come. Take a look at Mud Hole's Custom Builder series rods. They come in 5 different colors that will appeal to both girls and boys. Swampland for that matter has the same thing from a different manufacturer. They're really nice blanks for the price. I'd couple those spinning rods with underslung spincast type reels.

Bill in WV

If you cut 2 feet off the blanks from the butt, you'll greatly alter the action. It will become, much, much slower. You're talking about taking off roughly 30% of the total length. I'd rather have a beginner working with a medium to medium fast action rod than a slow action rod, which is what's going to happen if you lop off that much from the butt.

I'd take a hard look at the various offerings and try to find something is closer to what you want in length right up front. The less you trim, the less you'll change the action and power.

Remember that with the CCS, you can effectively determine the action and power for any length before making the cut.

Thanks, Tom and Bill. I had decided on a underspin reel the first time I saw one. It looks like it would be easier to "trigger" than the standard Zebco that I learned with, plus it will get them accustomed to reeling with the left and holding the rod with the right hand. I like the Mudhole offerings, because of the colors, but they are graphite. I will go with the Batson E-glass, because of the extra durability. I conviced my son that black was "cooler" than green. His younger sister wants everything that her older brother has. So, I have her buy-in as well. We've started to pick out components. Now, if I can just get them to accept the look of a split grip...

I did three Mudhole blanks for my granddaughters. I left them 5 1/2' since kids grow fast. These little blanks are very light and a pleasure to fish with. I would not shy away from them because they are graphite. They are lighter and more responsive. I don't think a child could break it if he tried.

[www.rodbuilding.org]

I too recently built four rods for neices and nephews, using the mudhole custom blanks. 6 to 10 lb ,cut 6" off the butt with a chop saw, making them 5' 6''. Set them up as spinning rod's using the spincast reels with the trigger also. I used pac bays Illusion guides with the holographic rings to add some bling, that kids really seem to like. Good luck on your rods and enjoy taking the kids fishing.