Although coming from the composite industry, I just recently fabricated my first foam-core, CF-skinned grip. Observations of the pre, actual, and post process has prompted me to offer my experience of the process and end results. Admittedly, they do not fall in-line with what I have learned to be the accepted properties/attributes/qualities of foam-core grips; specifically weight (objective) and sensitivity (subjective) and durability (a combination of both).
Weight: Many claim foam-core grips are lighter than cork; my findings suggest otherwise. The foam I used is a commercially available, rod building foam of 18lb/cf density (granted, quite dense), 1.25in OD X .315in ID X 14in long which weighed 5.6g. An equal length of 1.25in OD with a smaller .25in ID cork rings weighed 3.7g = 1.9g lighter. Factoring in possible lighter foams, say 6lb/cf, its weight would be 1.9g or 1.8g lighter than the cork. It is obvious the foam I used was considerably heavier than cork but lower density foam could be slightly lighter; but we have not skinned it yet!
The longest section of the grip I made was 10in. A 10in length of 1.25in dia. woven CF sleeve weighs 5.5g. Add to that 4g of epoxy = 9.5g required for the skin over the foam. Without even including the weight of the foam core itself, the weight of a foam-core / CF skinned grip is 5.8g /64% heavier than cork by itself! If you want that perfectly smooth, shiny surface coating on the CF weave, the weight can easily double that of its cork counterpart!
Sensitivity: Foam, whether rigid or soft, is comprised of random cells. Uninterrupted sound waves travel in a straight path. Due to its inherent structure, foam is used as a sound-deadening material to interrupt and diffuse sound waves. While possibly better than cork, I consider the claims of foam-core grips enhancing sensitivity/feel/vibrations of the blank to be exaggeration at best; the CF skin = yes but the foam-core = no.
Durability: No one can argue that a CF skinned, foam-core grip will ultimately withstand more abuse than a cork grip, but to what extent/parameter? While the CF grip may survive greater blunt force trauma, minor scratches may be more visible on the shiny surface of the CF grip while undetectable on the cork. When all is said and done, it is safe to say the foam-core/CF grip is ultimately more durable.
So those are my observations, opinions and offering here. While I realize it may ruffle-some-feathers, I am certainly not implying other views are wrong but possibly worth a second look. Afterall, we are ALL here to learn.

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

If you had used the foam density recommended by the inventors, you would have found the grips to be lighter than the same size and shape grip in cork. You can't disregard the "recipe" and then state that the weight claims between these grips and cork is in error.

The original claims made on behalf of foam-core, carbon-skinned grips remain true - they are lighter than the same grip made from regular cork.

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The density of the foam cores you used are denser than the foam cores used by CFX and NFC. I believe most foam cores used for CF grips vary from about 4 lbs/cf to 8 lbs/cf, I think 18 lbs/cf would be very strong but on the heavy side.
Norm

Tom & Norman,
You are both correct until factoring-in the weight of the actual foam itself which WAS NOT INCLUDED in the final weight of the piece. A 10in long length of CF sleeve (5.5g) added to 4g of epoxy alone = 9.5g which is considerably more than a longer, 14in length of similar cork rings (3.7g). Maybe I have extremely light cork rings!?!? Even with the weight of the foam-core excluded, the combined weight of the CF sleeve and epoxy alone exceeded the weight of a cork substitute.

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

Mark, did you only weigh the cork rings without gluing them up?

Phil,
Thank you for your interest. The cork rings were weighed separately, without glue, but good point/observation. I cannot imagine the weight of the epoxy to bond the rings together exceeding 2g, probably less than 1g.

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

It take me maybe a good 20 CF Grip to have the processus right (with test of different process and product).
I can now make grip as I like (to be told to have at the end thé exact diameter I wanted).
Multiple test told me I can now only gain weight on the core (for the finish I want).
For fly Grip, in the size and shape I use weight in Cork is 14/16 grammes, my CF are in the same range, so for le no gain in weight.
For the record the final core after shaping/turning before adding sleeve, epoxy.... is in the 7 grammes range.
So it is, at least for me.

I wait too long to test CF Grip, I now build all my personnal Fly rod (mainly line 4 and 5) and UL to ML lure rod with homelmad CF Grips.
After one or two year of use one good washing and like as new, no slippery at all, on the river dirt or slime come off easy and I really like handling them (I like my grip smooth, not textured).

________________________________________
@+
Eric
[www.emfishing.fr]



Edited 1 time(s). Last edit at 04/18/2021 02:41AM by Eric MONTACLAIR.

Mark,

Something is wrong. I was the co-inventor of these grips and we made dozens before publishing the article. All were measurably lighter than the same grip size and shape in natural cork, most in fact, were 40% lighter than the same grip in cork.

Measure the final weight of the completed grips, not the component parts used prior to assembly. If your foam core skinned grips are heavier than cork, you're doing something wrong. What weight carbon skin did you use? It's only there to protect the core so you can get by easily with the lightest weight material.

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On the bright side, the weight of the rod grips is almost all un-leveraged weight. The effect of a coat of paint on a rod blank because of leverage would probably exceed the addition of a couple fractions of an ounce saved in the grip. In reality it all goes back to ounces, inches, and multiplication, not personal opinions.

Phil,

Mark's point seemed to rest solely on the idea that the CF skinned grips were actually heavier than the same grip in cork. Depending on the lb density of the foam and skin thickness, they're not. If we parlay grip weight into how it affects rod performance, then I certainly agree with all your points.

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Tom,
You are correct; something was wrong and it was my measuring; I stand corrected. I decided to check my weight measurements with my "clean" scale rather than the scale I use to measure epoxy which has been used extensively and thus been spilled on and the lens over the numeric display a little difficult to read through. Excuses, excuses; I should have realized I was adding a decimal point. The foam (18lb/cf) weighs 56g, not 5.6g and the cork 37g, not 3.7g. We all agree 18lb/cf is denser than required = computing the same size piece of 6lb/cf foam would be 18.6g which is half the weight of cork at 37g. BUT, when adding a same length CF sleeve and required epoxy, 9g + 6g = 15g, the finished weight would be 33.6g. While the foam core / CF is admittedly lighter, only by a small margin, 3.4g or 9%. But those desiring a smooth, shiny surface may be adding enough weight in epoxy and PG to make the final grip the same weight or slightly heavier.
I have been purchasing not only woven sleeving but rolls of CF, Kevlar and FG fabric from Soller Composites for more than 20 years, much longer than I have been building rods. Jon Soller is a very nice, knowledgeable and helpful guy, runs a great business and carries very high quality composite fabrics; definately an A+ supplier! While there are some working properties of his epoxy I may not care for, it is probable the clearest, most non-yellowing laminating epoxy available.
I used Alps foam from Batson due to being available in 1.25in OD and 14in long. While denser than required, it machines, sands and shapes beautifully, better than any other foam I have used. Divinycell H45 foam (3lb/cf) has been my go-to flat core material for composite structures and actually employed it in my very first rod build 6 years ago, before learning you had already invented it.
The cork rings used for weighing were purchased at the 2018 or 19 ICRBE. They are very high quality, better than any others I seen yet half the cost of other premium rings; I use them sparingly.
The reason I decided to finally build a foam-core / CF grip is that I have been wanting to fabricate a rear-grip / hidden reel seat / fore-grip UNIT which appears to be 1-piece, completely covering the reel feet with only the stem of the reel seemingly protruding out of the shaped grip. Although I produced a similar effect with machined olive wood, the feet of the reel were exposed. The only feasible way to entirely cover the feet was to employ fabric, in this case CF. Although possibly not the first to produce such, it is finished, rather unique, it works and may be the most comfortable spin grip possible short of additionally employing CAD CAM contouring.
We will have to wait until after fishing it to see if it converts me from being a cork advocate.

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

Andy Dear always preferred the 6lb foam while I liked the 8lb stuff. If you make any from either weigh those and see what you get.

Interestingly, it is the bad cork - the stuff with all the pits and holes that is the lightest cork, for obvious reasons. I'm betting you bought some CG1 cork at the Expo from Mickel's Custom Rods.

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Tom,
I attest 3lb/cf foam would supply the required crush resistance for a rod grip unless heavily abused or used to bludgen people. I used .375in thick 3lb/cf Divinicelll foam as the core for my 8ft Kevlar/CF micro boat and the only dent in the hull after all these years came from quite a substantual impact. But, as stated above, it does not machine or shape anywhere near as well as the heavier, micro-cell Alps foam.
You are correct; I purchased both some CG-1 and CG-2 cork. Actually, Norman Miller was the person who purchased the cork for me at the Expo and he mentioned showing it to you for your opinion; you were impressed as well. I am uncertain who the vendor was but you are probably correct on that account as well. Is Mickel's Custom Rods still around?

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

It was Mickel's Custom Rods. He got the cork from me a few years earlier. Very good stuff indeed.

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Tom,
Then a thanks to you is appropriate as well. I would have purchased more, but I think Norman purchased the last of his stock at the time. While I suppose anything is possible, I cannot imagine finding any better cork without paying $10.00 a piece.

Believe it or not, but Sammy carried that cork to at least 3 or 4 Expos before somebody bought it.

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It was Mickel’s. I bought everything he had, and If I had known he had it at previous expos, I would have bought it all a lot sooner, and Mark would not have gotten any. Since Mark asked me before the expo to buy some good cork for him, he basically got it all. I did buy several vintage Fenwick fiberglass blanks from him the year previous, but did not notice the cork at the time. You don’t know how lucky you were Mark!

Weighed a CFX CF full Wells grip vs a cork Full Well grip of approximately the same size, and the CFX grip was a few grams lighter. I also had an NFC grip, it was also lighter, but it was also a little shorter. The CFX was lighter than the NFC grip even though it was larger. Obviously different density foams were used.

Norm

Norman,
While extremely pleased with the cork you purchased for me back then, I supposed you are correct in not knowing how lucky I was (and still am). Now you're starting to make me feel guilty lol.
Thank you for taking the time to weigh a few different grips and offer your findings here. With my initial (incorrect) weighing, I was surprised to discover the foam core was heavier than cork (which proved to be wrong). After re-weighing and combined with your findings, it is safe to say the foam grips may be lighter but possibly not to a large extent. To be honest, my 7ft + UL trout rods could benefit from a little extra weight behind the reel to help balance the rod to my ultimate liking.

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

Measuring only Flor grade cork, I have measured significant variance in cork ring weight - about 1/3, meaning it takes 3 rings of the lightest stuff to equal the weight of two of the heavier rings. And I would say that the rings I measure are genuine flor grade. So depending on the weight of your cork, I wonder if some cork may still be lighter than CF.

Not sure what flor grade is as there is no listed nor photographic standard behind it, but I'll assume you mean it is very clear and free of pits and holes. The stuff that Mark bought is CG1 grade which is the highest verified cork grade available. Although being a natural material I'm sure Mo is correct that not all cork rings are going to weigh the same. Still, I think you'd have to look long and hard to find enough super lightweight rings to best a properly made foam core, carbon skinned grip. Even then, the foam-carbon grip will have a higher stiffness to weight ratio which provides more benefits than simple weight savings, and which are really the point of such grips in the first place. There are, however, many instances where cork is still an idea grip material.

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