I've got some 3/4" aluminum pipe to make spinning handle extensions for some shooter blanks. I haven't done this type of grip in a long while. Anyone know if size 18mm Fuji NPS spinning reel seats will fit snugly over 3/4" pipe? Or, would I need to order 20mm seats?

3/4” equals 19.05 mm, so you would definitely need a size 20 mm seat. When I do an extension I use a piece of blank as either an insert or a sleeve. It’s lighter than an aluminum sleeve plus the bushing.
Norm

Ladd,
Aluminum (Al) butt extensions can work very well; they can certainly be strong, easy to work with but as Norman mentioned, can be a bit heavy = it all depends on the flavor (alloy) of Al. Much of the Al found in stores such as Home Depot is 6063 “architectural “ Al which has good corrosion resistance but is rather weak compared to other alloys. 6061 is the most widely used Al alloy due its good compromise of strength, corrosion resistance, formability, machinability and weldability. However, when the highest strength to weight is paramount, such as a fishing rod, it is hard to beat either 2024 or 7075. While 6061 is adequate for an extension, 2024 or 7075 will be stronger and lighter albeit more expensive. Using a stronger alloy will allow for a much thinner wall = less weight.
Most .75in Al tube found at Home Depot type places are .125in wall = way overkill and overweight. McMaster Carr offers a wide variety of Al alloys, diameters and wall thickness. I have built two 20lb live-bait calico rods, extending the butt 18in with .625 X .049in wall 2024. With your extension probably being much shorter, you could even use .035in wall 2024, but stick with .049in or .065in if using 6061.
I realize that I did not answer your original question, but Norman already did. I just wanted you to know that there may be better options than what you presently have.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Ladd,
Do you have 3/4 Aluminum Pipe or 3/4-inch Aluminum Tubing?
3/4 Aluminum Pipe (3/4 NPS or Nominal Pipe Size) will have a nominal outside diameter of 1.050 inches (26.67 mm).
3/4-inch Aluminum Tubing will have an outside diameter of 3/4 (0.75) inch (19.05 mm per Norman's response.)

This is a lesson most young engineers and designers learn the hard way, NPS does not equal actual diameter.

A minor disagreement with Mark's response; the density difference of readily available aluminum alloys will be small (0.0975 -0.1015 lbs per cubic inch, a 4% range), while the physical properties vary greatly from alloy to alloy the weight difference will be small enough to be considered negligible, at least for most people.
My apologies for some of the excruciating detail.
Morgan Hanscom, P. E. retired

Morgan is exactly correct on all accounts. The weight of different Al alloys is negligible, at least for our purposes. However, the yield strength difference varies vastly; 6063 = 21,000 PSI, 6061 = 40,000 PSI, 2024 = 47,000 PSI and 7075 = 73,000 PSI. Simply put, the stronger the alloy = the less material required = less weight. I tried to explain that in my first post “Using a stronger alloy will allow for a much thinner wall = less weight.” A similar comparison can be made between a CF blank vs a FG blank. Morgan is also correct in the dimensions of Al tubing vs Al pipe. Basically, tubing is measured on the OD whereas pipe is measured on the ID. Tubing dimensions are quite close while pipe dimensions can vary considerably (I hate pipe and only use tubing for fabrication). Although Ladd stated having pipe, I assumed (possibly incorrectly) that he actually had Al tubing which is much more prevalent than Al pipe.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Looking at the McMaster Carr site Mark referenced, they sell graphite tubes! Low modulus (33-36) and high modulus (57-63) options.


I believe the old rodmaker article for extending blanks said to use lower modulus for extending blanks.

What would the ideal wall thickness be?

Seems to me the extension in many cases is just there to hang the components off of, if that is your case than why can't you use your graphite tube grip as a structural member? The buttcap in function is just a plug for the end.

Hello All.

Vol/Issue Article Author Page
13/5 Blanks: Extend-A-Butt. By Bill Colby. 24
6/3 Blanks: Extending Your Rod . By Tom Kirkman. 22

Found these with a quick look.


Tight Wraps * Tighter Lines.

Looking for black cork rings for flyrod grip.....or can natural rings be dyed black after shaping?

Dean,
Yes, McMaster Carr sells CF tubing, both uni-directional bias-ply (0*/90*). They also sell Ti and FG tubing but in limited sizes. Make certain to use the bias ply (for the additional hoop strength) if CF is the desired material. While a lower modulus blank extension than the blank itself may be optimum to not overcome / overstress the blank where they connect, that is not the entire picture. Basically, higher modulus = higher stiffness but at the same time, thicker wall lower modules = higher stiffness as well. Both need to be considered. In the grand scheme of things, the modulus is more important further up the blank (as with a ferrule) where more flexing occurs than at the stronger / thicker butt end. If one were to use a CF tube for an extension, I would think the .035in wall would be a good choice up to about 20lb rods, maybe even 30lb.
Spencer,
Foam core (sandwich) composites can offer an incredible stiffness-to-weight ratio. However, in the composite industry, both (all) sides of the core must be skinned to achieve it. When a bending force is applied, the tension exerted on the outer skin counters the compression exerted on the inner skin; the further the two skins are separated = the stiffer the structure with minimal weight gain. A relatively large 1in diameter foam core rod grip may very well be up to the task you suggest but THE ID OF THE FOAM CORE WOULD HAVE TO BE SKINNED! Not only to complete the sandwich construction but to resist the end of the blank from digging into the foam from the leverage exerted by the length of the blank. While skinning the ID of the foam core could be accomplished, it may prove to be quite a PITA. Additionally, one ply of fabric on the OD and in the ID may be enough for UL to light rods, but I would opt for at least two plies each on any rod heavier.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Don,
I cannot answer your question from experience, only suspicion. Cork is basically a closed-cell material and I would think attempting to dye it would only cover the very outside “skin”. I would also worry about the dye coming off in one’s hand with the constant gripping. Just my thoughts and nothing more but hey, maybe it can be done. Test, test, and test again or wait for a qualified answer.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

cork can be flocked black..better, use urthane core then flock.mudhole has urthane cylinders..



Edited 2 time(s). Last edit at 01/05/2022 08:46PM by ben belote.

How thick does the rings need to be? Rubeized cork gasket material is pretty black.

Or use a burnt type cork. Very dark brown.

...........

Ladd,
Are you still with us?

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

You can get nice and heavy black rubberized cork that will do fine - but be heavy.

Or, you can use very light clean cork and then when completed, just wrap the cork with black plastic electrician's tape and you will have a black appearing cork grip.

Best wishes.

Don,
"Here are some dark cork rings"

[www.hffcustomrods.com]