I am looking to make my own foam cores for carbon fiber grips.

I make ice fishing rods and I want to make the cores so that they are tight to the rod, butt diameter .125-.1875 is common.

Is it possible to use pvc 1' id x 5-8 inches long, with caps on each end and running .0625" hardened rod for the mandrel?

Plan on using foam from Riley Rods.

Will the expansion split the pvc?

Will one weight foam be more prone to splitting?

Will it blow the ends off.

I have ideas for clamping the caps.

Thanks for any input.

I will be trying and will let you know how it goes.

Thanks, Doug

See you on the water, Doug
Captain Paddlefoot

You will first need to make a mold out of rtv silicone of a cylinder inside the PVC. Then you can cast your foam inside the rtv which rests inside the PVC which has been split.

Look at the Riley website at their molds.

If you read the original articles, you may note that you can pour the stuff in rectangular pie pans and then just pop it out and cut long turning squares. The mandrels can be poured inside the pieces so they're ready to chuck once cut into individual turning squares.

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

I think you will have trouble turning the foam to shape on a mandrel that small.....too flexible!

What I've been doing is using Riley's preformed cores which are 3/8" i.d. I then a put a Forecast shim on the lathe and carefully sand it down to 3/8" o.d. Then after I've shaped the Riley core I epoxy the Forecast shim into the center of the core. That gets me very close to the o.d. of most ice rod blanks. From there just use a little masking tape to build up the blank and you've got a pretty good fit.

Thanks,
Chad Huderle

Huderle Custom Rods
Prior Lake, MN

Why not use his 1/4" cores than?

Thanks, Doug

See you on the water, Doug
Captain Paddlefoot

Tom Kirkman Wrote:
-------------------------------------------------------
> If you read the original articles, you may note
> that you can pour the stuff in rectangular pie
> pans and then just pop it out and cut long turning
> squares. The mandrels can be poured inside the
> pieces so they're ready to chuck once cut into
> individual turning squares.
>
> .............

Before I had the mold from Riley Rods, I did it the way you described. I poured it in to a cake pan and would use the radial arm saw to cut my squares. Then I would use a drill press to make my hole for the mandrel. The problem I had was that it seemed I had more voids with the pan.

Doug -

I have never done what you are trying to do, but I think there are some good points raised. First is the one made by Phil - I don't think even a hardened steel mandrel at that small of a diameter would work...even if kept short. Even a 1/4" hardened, oiled drill rod flexes noticeably. So you are probably going to need a larger mandrel.

Then you need to figure out how to shim it to fit that tiny blank. If you were going to use thread or fiberglass drywall tape or masking tape as your shim, then a 1/4" Riley Rods core would work. If you are going to try to use an arbor, you don't have much room to work with on that 1/4" opening. So, Chad's method of using 3/8" - while it sounds strange - is actually more workable since it keeps you from turning down to paper thin dimensions.

I am surprised to hear Jeremy having voids in the pan style pour. My experience with them is that they turn out very well...maybe the best of the methods. The only downside is that you have to bore them and then since you are starting with a square you get more waste than with a round core like Mike's from Riley Rods. You get waste from the kerf of your saw cutting them into squares and then you get a lot of waste turning a square to a round shape. But you can make as many as you want out of one mold (baking pan). The silicone molds - no matter how good - will eventually fail, either because of use or age. But you can get as many as 100 cores out of a Riley Rods mold and that makes them a ridiculous value all things considered. So pick your poison - waste foam turning or waste the molds once a year or every 100 cores.

Remember that you can also skin a cork or EVA grip if what you want is already available. Not saying that is perfect but don't forget the option of taking an already formed grip and skinning it.

If you are bent on making a core with no shim, I'd use 2# or 4# foam in the cake pan, bore it to diameter, and turn it very carefully with sharp tools at moderate speed on a short (5" - 6" if I could get away with it) mandrel of the desired dimension. I think you can manage it if you are CAREFUL. But if it were me I'd just go with Chad's method...I bet you can't tell his grips are 3/8" diameter once the rod is built.

Hope this helps.