I think the term "foam arbors" causes a misunderstanding. They are made from polyurethane foam but once cured they are no longer foam like Tom says. Probably better to just call them "polyurethane arbors".

roger wilson Wrote:
-------------------------------------------------------
> Mo,
> Won't one of these work?
>
> [flexcoat.com]
> at-arbor
>
> If you need the od to be smaller, just slip a
> bolt up the inside of the arbor and put on a nut
> to make it tight.
>
> Then, chuck the arbor into a drill and hold the
> arbor against a spinning belt sander or even a
> piece of sandpaper that is stuck to a bench.
> Then, bore the inside to match the od of the rod
> blank and you will be set.
>
> Simple, readily available and inexpensive.

Roger that is exactly what I use and would recommend it for this builder

Terry Kirk Wrote:
-------------------------------------------------------
> I make most of my arbors from wood.
> ...
> Using more rigid material allows you too use less area ...

Terry, I was wondering what kind of wood you using and what thickness are the arbors.
I'm interested because of the three materials: masking tape, polyurethane and wood...wood is hands down the better material for transmitting a vibration.
(And that may not hold up once you smother the arbor in resin.)
That sensitivity may not be measurable with a human hand...but it is measurable.

No, the rigid foam is much better at transmitting vibrations than the wood. Wood, is rather heavy for the stiffness and will damp vibrations. This is why wood is chosen for tool handles such as hammers - it tends to damp vibrations better than lighter, stiffer materials.

Keep in mind that fishing rods made of wood, even ash, hickory or cedar, do not transmit vibrations nearly as well as glass or carbon rods. Arbors or bushings made of wood are no better.

........



Edited 1 time(s). Last edit at 12/23/2021 12:21PM by Tom Kirkman.

Mo,

Have you actually used any of the rigid foam arbors? The stiffness to weight ratio that they offer is vastly superior to anything else mentioned in this thread. If you want the maximum vibration transmission possible, you're going to be hard pressed to do better.

............

I work at a place that builds large air handling units. Mostly for universities, hospitals, and pharmaceutical companies. The panels we use for the walls and roofs are made in house, and are filled with polyurethane foam. I am not sure what density the foam is, but I can assure you they are very strong panels. The panel's inner and outer skins are sheet aluminum. Either .040" or .063" in thickness, and we have to walk on top of the units to foam voids that are created between the panel frames, and the extrusions we use to join them. We use polyurethane foam to fill those voids.

Our foam is a two part system. Our main foam machine uses 600 lb tanks that are pressurized via nitrogen tanks. Hoses run from the tanks to a valve system that meters the amount of each part, which is then sent through hoses to the foaming gun. The mixing of the two parts takes place in a replaceable tip on the foaming gun. We then shoot the liquid foam into the voids and hollow extrusions and the foam expands to fill those voids. In our case, the foam is used as insulation. It's a pretty simple process, but it does have some tricks to it. I've also went out in the field and built our units on site. When building on site we do what we call "cup foaming". Where we pour equal parts in cups and then pour them into one cup, mix them together with a paint stir stick, and then pour the solution into voids to fill them. Again, pretty simple process.

What I am getting at is this .... it would be very simple, using similar product, to make your own round stock, and then bore a hole of an appropriate ID, through its' center. You could make it as long as you want, and simply cut it to length. A piece of PVC tubing or steel conduit with an ID that would give you the OD stock you require. Spray the inside of it with mold release, and fill it with foam. Once cured just push the piece out, and do what you need to do. The foam we use is very strong, and very light weight. I have ran pieces of it over with a scissors lift, and while it will compress it. it won't completely flatten it.

I looked on Amazon and they sell kits in 5 and 6 lb densities. That would be the route I would go. It would be easier than the disk making procedure I outlined earlier.



Edited 3 time(s). Last edit at 12/23/2021 11:55AM by David Baylor.

Tom Kirkman Wrote:
-------------------------------------------------------
> No, the rigid foam is much better at transmitting
> vibrations than the wood.

I stand corrected.
In testing the black polyurethane arbor against basswood...the polyurethane transmits vibration better.
Not only better....but WAY better.

6lb density is ideal. 8lb is not out of the question if you want even more rigidity and hardness, but it will weigh just a very slight tad more in the sizes normally associated with seat arbors.

........

Chris Catignani Wrote:
-------------------------------------------------------
> Tom Kirkman Wrote:
> --------------------------------------------------
> -----
> > No, the rigid foam is much better at
> transmitting
> > vibrations than the wood.
>
> I stand corrected.
> In testing the black polyurethane arbor against
> basswood...the polyurethane transmits vibration
> better.
> Not only better....but WAY better.


Basswood is a soft wood. Do a search and you will learn what woods are hardest then get some and retest.

No wood is going to be anywhere near as good at transmitting vibrations as the foam polyurethane material. And the harder and heavier the wood, the worse it is in that regard as the stiffness to weight ratio falls that much lower. Wood, in fact, is praised for its ability to damp vibrations and remains the #1 choice for woodworking benches and assembly tables for just that reason.

..........

Mo,
Can you do us all a favor.
Take a foam arbor with its 1/8th center hole and sand it down to size for your reel seat.
Then, weigh the foam arbor , with the reel seat and the rod blank.

Then, take a roll of masking tape and place rows of masking tape on your rod blank, leaving 1/8th inch gaps between the rows.

Then, Then, weigh the rod blank with the masking tape on it, with the reel seat and see what you have.

The weight of any adhesive to glue the arbor, and the reel seat to the arbor - will be pretty similar to the weight of the epoxy to coat the masking tape to secure the reel seat in place.

Then, let us know -- down to the gram - what the weight difference is - after doing these tasks.

I really believe that you may be surprised at the total weight required to secure your reel seat to your blank - using either method.

I also think that you may be surprised at how little different the type of arbor, or reel support - of many different method you might use - that is weight specific and causes or results in a loss of sensitivity of the blank.

But, do the tests please and let us know what you find.

Best wishes

The polyurethane will be significantly lighter than the same size arbor in masking tape (which is already coated with adhesive - that's why it will stick). The larger the arbor, the greater the difference will be. We did this test in a past issue of RodMaker.

...............

Roger why don't you do test it so that you're not giving people inaccurate information? The only person who will be surprised is yourself, everyone who has tested already knows there is a significant weight difference between the 2.

Billy :-) Good point.

If Mo could find arbors with an 1/8" bore he wouldn't have started this thread. If you know of a source please tell us Roger.

Otherwise it is get some PCV pipe, a piece of drill rod stock, and pour your own as David suggests. I'd keep the drill rod in and turn it on a lathe to make sure it is centered. Make the PVC large enough for your biggest handle as it is easy to turn them down' as needed (1/2"Sch 40 is roughly 15.7 mm ID IIRC).

Next best is settle for the Flexcoat ones with 1/4" bore and add thread arbor(s) as needed.

Russ in Hollywood, FL.

Everyone agrees that a foam arbor is nice and light.

If the only problem is a 1/16th difference in the diameter of the rod blank and the id of the foam, put two or three wraps of masking tape on the rod blank, glue everything up and get on with your build.

Any gram weight difference is not worth the talking about.

But, so what works for you the best.

Just as a double check, take a fit the foam arbor to the id of the reel seat.

Then, slip the arbor inside the reel seat and place the reel seat on the rod blank and weigh the assembly.

---------------------
Then, take the assembly apart, put in the few wraps of masking tape necessary to fill the void and weigh the assembly again.

Let me know what the weight difference is please.

p.s.
There are 28 grams in one oz.

------------------------
Please weigh the assemblies to verify the difference of the assemblies to see if it is worth any effort at all to persue the matter any further.

===================================
Lets also put this in perspective.

I would doubt that much more than 2 out of 10 people could pick up a fishing rod that is 4 grams less than another similar rod and be able to reliably tell anyone the difference.

I am not talking about a gram scale, I am talking about your hand.

Now to be fair, because that is what this is all about, before you do the weighing, install the reel that you are planning on using with the rod.

Then, transfer the same reel to each rod and determine exactly which is heavier.

If you have a 2 oz rod and put on a 7 oz reel and want to feel the difference between 2 or even 4 grams - I believe that it is out of reach to have any one accurately determine the difference.

Simply put, be worried about weight - but don't become obsessed with it to the point of not being able to tell the difference by holding the rod in your hand.

Best wishes.

Hmm, he needs a bore of 4 mm. The flexcoat arbor has a bore of 1/4" or 6.35 mm. Standard 3M masking tape is 5.5 mills thick.

If my math is correct he would need 8 wraps of masking tape. Call it 10.25" of tape for two arbors. Don't happen to have a scale handy.

Russ in Hollywood, FL.

Before I'd use tape to shim that amount, I'd close spiral wrap some D thread where the arbors will sit.

...........

Mo,

What you feel in the rod is rotational impulse, or change in angular momentum, rather than a wave. The inertia of the rod is the biggest enemy you have to fight in the sensitivity department. Light rigid foam is your best bet, and as Tom mentioned, only a couple relatively short and well placed pieces are required, particularly for your UL applications. If you want want that rigid direct connection, you should be able to source some carbon fiber discs, make your own using graphite fabric and resin, or use some poker chips. Split the foam arbors in half and epoxy the discs in between.

Personally, assuming spinning rods are the application, I would use a sleeved foam core grip with the grip section at the reel only long enough to fill the hand and the reel wrapped on with thread and epoxy. It's how I do my bass rods, and I think you will be hard pressed to find a lighter option. Discs can be embedded to sit under the reel feet if desired before sleeving. At that point, with the UL applications, a butt grip could become optional, although I like to have a grip that reasonably fills the hand for two-handed casting. In your applications that may not be necessary.

Been super busy so just got back on again.

THANKS to all who replied. Am genuinely grateful. Responding below from memory to the questions or comments.

1. Tom. Thanks for the observations and Q. I have not actually used the foam arbors before. I have one from many many years ago when the first articles about carbon sheathed over foam arbors came out on Rodmaker. I never used it because whatever I got was crumbly to the touch. I could rub my fingers on it and crumbles would come off easily. So I just wrote that off.

2. Given all the comments here, I'll try Foam arbors again. Probably 8 lbs. For sure the overall 'voting' is for the foam arbors.

3. Thanks to those who suggest that I just pour my own. I supposed I could but for now, am not sure if I am up for the effort as I don't need a lot and just need to test.

4. Often, when I float weight questions, there are responses from a few that say a few grams doesn't really matter and/or can't be detected etc. Just to clarify:
a. I enjoy simply pushing the envelope on what is possible.
b. For UL, 4 grams difference (mentioned by Roger) is huge. I have 6' 7" rods at sub 28 grams and am in the process of trying to bring it down to 25+ grams. These have the most comfortable grips I have ever encountered (Tennesse style from cork and shaped to my hand). Adding 4 grams to that rod would definitely be noticeable. I have a 6' blank right now that is about .37 ounce which I will get around to building eventually . That one will be 'crazy light' once I am done....:) Maybe 21 grams. Spinning reel is a hair under 5 oz so the whole rod/reel is sub 6 oz.



Edited 3 time(s). Last edit at 12/25/2021 03:46AM by Mo Yang.