I want to experiment with a 5' medium power fast action rod for skipping in tight places under docks. I have a 5'6" blank on hand that I'm thinking about cutting down but I am not sure what impact cutting the blank will have on its power and action. I think if I take all 6" off the tip I'll have a much faster action but much slower action if I take all 6" off the butt. If I take 3" off each end will I leave the action unchanged? How will cutting the blank change its power? I've looked through the library and done a search through the forum but haven't found anything on this topic. Anyone have any experience or advice? Thanks for your help!

Phil,
I cut blanks down all the time and sometimes just a couple of inches makes a pretty big difference. I build quite a few saltwater boat rods and usually shorten them from 2-6 inches. Depending on the type of action you desire, try cutting just a little bit at a time. If you like the action of the tip just cut the butt or vice versa. I would first try just a couple of inches say from the butt then see how the blank responds. You can always cut more off if it isn't exactly what you want but be careful about cutting too much. Taking 6 inches off a short blank like that wll make a substantial difference. Randy.

"Table of Effects of TRIMMING or EXTENDING a ROD BLANK"
[www.rodbuilding.org]

First of all, slow down - taking 6 inches off the TIP-end of that rod will almost certainly destroy its usefulness as a casting instrument. Chances are that taking anything more than 2 inches off the tip will make a big change in the action-taper of that rod, and greatly raise its lower lure-rating. READ the "Table" carefully, and THINK before you do anything more drastic.

Phil , your e-ddress is HIDDEN, so I can' t make this easier for you, because I am in a rush. You will have to use the RBO Search Feature and get your own hyperlinks. Copy into the Text box and Select "Subject" or "Author" as appropriate.

Here are 3 more references for your education, before you fall into the School of Hard Knocks:

Re: newbie question Tom Doyle Aug. 14, 2005 01:24PM
Robert Crabtree suggested taking 3" off both ends. Think long and hard before doing it this way. Taking any appreciable length off the tip drastically alters power and action (increases power, decreases action), because that is where most of the rod's flex is. That said, I have rebuilt rods that had a piece of the tip broken off (such as by the "car door trick"). The rods are often fine, they are just very different from the original rod. Taking length off the butt end has a less drastic effect. So if you want to approximate "the same rod, only shorter", take it off the butt. …

Cut my butt or clip my tip! Scott Lewis Nov. 8, 2005 19:13
Let's say that I want to get a GSB-132-1M for fishing MTK [Montauk] etc throwing plugs to 3.5oz. But I have to take off 6 inches because the one-piece doesn't fit in my truck. Would you either cut off 6" from the top, 6" in from the butt or 3" from both. I understand that taking from the tip will stiffen the action and that removing part of the but section can soften the action to a degree. I just want to know what you would do in this situation. Thanks! Scott

Re: Cut my butt or clip my tip! Tom Kirkman (Moderator)
11-08-05 19:56 ... Not quite. Cutting from either end is going to make the action slower. ... Pay special attention to Kirkman's method for pre-testing the effects of trimming by tying the lure to a cut-point.

rod blank questions..... Vincent Koon June 24, 2005 12:44PM

Gotta go, man. Good luck, -Cliff Hall+++

Action - Shortening the blank from either end will slow the action.

Power - Cutting from the tip increases the upper casting weight limit, the power remains mostly the same. Cutting from the butt reduces the power, casting weight range remains mostly unchanged.


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Tom,
I agree with almost everything you said except I have to disagree about the affect on power of trimming from the tip. If we use the CC System to measure power cutting off part of the tip will increase the blanks power. If it is a fast action blank just cutting a small amount off of the tip can significantly increase the power.

You will come into the available power more quickly. But overall at the deadlifting limit, the power will not increase. I have to think you'll agree with that.

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Great information, thanks to all. It seemed like a simple idea, but I see it's a lot more technical than I thought. I think I'll find a factory blank that fits the bill!

Phil - If you can't find a 5 foot blank that seems right, and if your 5-1/2 foot blank is not too expensive, you should consider this:

Trimming ALL 6 inches from the BUTT will have relatively little effect on the lure rating and line rating, and preserve most of the rods casting function. It is just like using the same rod blank and holding it a little more forward. It will feel like a little of the backbone has been taken out the rod blank. And your handle section should be more compact, and your reel seat may be a couple more inches forward (closer to the rod tip).

Phil, regarding the rod blank from the reel seat forward, you can build this 5-foot version of that rod almost exactly as if it were the 5-1/2 foot blank. Just work on a proportional reduction of the rear & fore grip lengths. Also, consider if trimming the barrel length of the reel seat will help. Think of overall balance on the finished rod in your hand, because your casting accuracy in tight quarters is still very important.

You could probably trim 1 inch from the rod tip and not change its casting character that much. On this rod, 2 inches from the tip would probably be pushing it, and really feel like a stiffer casting tool. You can still trim the other 3-5 inches from the butt end, to give yourself the shorter overall length and great casting performance you are looking for. ...

If you are really in need of reducing the length of the rod blank between the reel and the rod-tip, then your strategy should be to move the reel seat forward AND trim from the butt end. I am not clear on why you need a 5-footer rather than a 5-1/2 footer. Is the Rear Handle too long? Or is the length of the rod blank forward of the reel seat too long for this casting situation? Or a little of both? A proportional reduction in your overall butt-to-tip layout should cover the latter case and reposition your reel seat accordingly ... [Are you using a "bow-shot" cast to side-arm skip these baits under those docks ...?]

Don't give up too soon, Phil Schwarz. You are on the threshold of success here, IMO. -Cliff Hall+++, Gainesville, FL cmkmhall@ufl.edu

Tom,
Your post has caused me to think more about the effect on power of trimming a blank from the tip. Here are my thoughts, see if you do not agree.
When we trim a blank from the tip the resulting blank will require more weight to deflect it a given distance. Mechanical engineers would call this the spring constant and say that the spring constant has increased. But the Common Sense System, that we have been using as our measure of power, uses a deflection of 1/3 of the blanks length as the point that we measure the weight and we call this the blanks power. Clearly if we trim something off of the tip of a blank it will require more weight to deflect the blank the same distance. However, when we trim something off of the tip of the blank the blank is now shorter and deflecting it 1/3 of its length is a shorter distance. But if we look at the stiffness profile of any blank that I have ever seen it gets stiffer rapidly from tip to butt, even slow action blanks. Therefore as we trim off of the tip of the blank the weight that is required to deflect the blank 1/3 of its length is also going to increase rapidly. The weight required is going to increase more rapidly than the length is shortened and the 1/3 of the length decreases. If the blank were of uniform taper and the action were just an arc that was uniform, or section of a circle, than as we trimmed from the tip the power would stay about the same, but no blank that I have ever seen has an action that is this slow.
So the power does increase as we trim from the tip.
I agree with you that the dead lifting capability of the blank, how much weight it can lift before it will break will not change significantly when we trim off of the tip. But this is not what we have been calling a blanks power. This is the blanks dead lifting limit which is something entirely different than than the power.