Trouble with crush grind pepper mill mechanism

[Chuck Jones]

What kind of glue should I use to hold the PKCrushgrind insert in the cap? I used epoxy only to find out it will not adhere to the plastic.

I just finished the best looking pepper mill I've ever built and intended to donate it to a Relay for Life auction tomorrow night. It worked fine until I had the bright idea of putting peppercorns in it. Forget it! The first slightly hard peppercorn caused the cap to spin on the mechanism. This is the first time I've used the crush grind mechanism and unless I find out I did something stupid, it will be the last.

Any suggestions will be appreciated.

[robert hainstock]

I'm working on one of those now. I'll skip the epoxy thanks for the warning. I may try gorilla. That is some slippery stuff.
Bob

[Tim A. Mitchell]

I have not used one, but would have thought that epoxy woul have held well. Robert, just be carefull of the expansion on the Gorilla glue.

What is the top of the mechanism made of?

[Chuck Jones]

I have not used one, but would have thought that epoxy woul have held well. Robert, just be carefull of the expansion on the Gorilla glue.

What is the top of the mechanism made of?

"Plastic" I don't know what kind, but apparently one that epoxy doesn't work on. I haven't used much epoxy. I just followed the instructions. It list several types of plastic that it will not work on.

[Brian Brown]

When I used a crush grind mech., I assumed that I would have the same problem, and because I was short of time, I used a file to scratch up the top of the aluminum shaft where it would sit inside the cap. I then inserted the shaft into the plastic cap, and used it like a file or sandpaper to rough up the interior of the plastic cap. Then some 60 minute epoxy, and it seems to have held well. Maybe someone else has a better idea. I will keep watching this thread.

[Chuck Jones]

Brian,
The shaft is not turning inside the plastic insert; the insert is turning inside the wood (black walnut) cap. The epoxy held to the wood, but peeled right off the plastic insert. I may not be understanding what you meant... and my terminology is not very specific because I don't know for sure what they call these darned parts.

I'm thinking maybe I should have crammed a lot more epoxy in the gaps on the plastic cap and maybe let it set more than the couple hours that I let this one set. In any case I'm going to try that tonight while I'm making another mill with the old fashioned deluxe mechanism.

[M Toupin]

Rough the plastic up with 100 grit or so. Epoxy, like most glues, are a mechanical bond and need something to bite into.

I'd not recommend gluing the aluminum shaft to the cap unless you fill it with pepper corns first and you intend for it to be a single use mill...

Mike

[Lonnie Cook]

Since I've only made one Crushgrind grinder (salt), I'm no expert ...

I used the model without a shaft. The outer shell had vertical ribs. The inner part had three fingers. I drilled the body that held the mechanism the same diam as the outer shell, then filed valleys for the ribs. I carved dents in the other part for the fingers to pop into. Epoxy held the Crushgrind secure, but the mechanical connection of the ribs and fingers kept it from turning in the body, or popping out.

- Lonnie

[Rasmus Petersen]

Im looking forward to the solution, but i think that you should have let it cure longer.. i would say 24 hours before straining the bond. there are from i can se on the page at the danish makers several kinds of mecanisme, for insertion into wood plastic and metal.

[Cary Swoveland]

Chuck, here are some installation instructions prepared by Woodcraft:

http://www2.woodcraft.com/PDF/77c14.pdf

Hope this might help.

Cary

[Ken George]

I have made several of these and use CA on top and bottom. Never had a problem. Every one who has received one of these loves them. Don't give up!

[Charlie Schultz]

I've also made several and used epoxy (the 60 minute and 5 minute stuff) with no problems.

[Greg Savage]

I'd not recommend gluing the aluminum shaft to the cap unless you fill it with pepper corns first and you intend for it to be a single use mill...

Mike

If need be, CrushGrind mechanisms can be filled from the bottom.

Use epoxy after roughing up your plastic. It will work quite well. Don't use CA if it can be avoided....It can be very brittle and fail when grinding coarse sea salts.....Certain salts can place some incredible torque on the mechanism.

Gorilla glue will expand to a point where problems will arise due to the glue filling in around the top of the upper insert. This makes it difficult to insert the shaft.

[Chuck Jones]

I think the suggestions to rough up the plastic make sense. Unfortunately I didn't see that or think about it until I had already gobbed a bunch more glue onto the top insert for another try. I'm letting it set longer this time before I try to grind pepper with it.

Cary: My crush grind mechanism came from Packard. I believe it's different from the one referenced to in the Woodcraft instructions. I think I saw a brand name of "PKCrushGrind" on it.

In the meantime I made another mill last night for the auction using the older type mechanism.

Right after I started trying woodturning I turned 10-12 pepper mills for Christmas presents and it went like a breeze. My wife asked me to make a couple things for the Relay For Life auction and I thought a pepper mill will be quick and easy for one of the things.

First one I turned out of willow oak and after I finished it I looked at it and the shape was coyote ugly.

Turned the second one using walnut and it turned out quite nice. Couple days later it had a crack in it.

The third one was from sycamore and the wood was just plain blah.

For the forth one I used black walnut and decided to experiment with the crush grind mechanism. Everyone absolutely loves the look of this one. We also thought we liked the mechanism until I tried to grind some pepper.

For the fifth try I used black walnut and the older type mechanism. It turned out pretty decent and maybe someone we don't know will buy it before anything happens. I hope the glue holds on number four. If not I have a decent backup.

What I lack in skill I make up for in tenacity.

Thanks for all the suggestions and help.

[Chuck Jones]

As stated earlier, I reglued the mechanism into the cap with a "gob" of epoxy and let it cure for about 24 hours. It appears to be holding, but I was not confident enough to donate that mill to the RFL auction. It all turned out for the better; my wife likes it and wants to keep it anyway.

Not sure what I've learned from all this. Had lots of people try to help including here and at Packard Woodworks. I like the ceramic grinder and I like not having to put the shaft through the cap, but it all seems a little too imprecise to draw much conclusion. If I try another one I'll try a combination of the suggestions you folks made:

1. Ignore the instructions and don't remove the little vertical ribs.

2. If the mechanism is too tight with the ribs, file some groves inside the cap (and in the base if necessary).

3. Rough up the plastic and use a lot of epoxy on both the top and bottom mechanisms

4. Let the glue cure at least overnight.

5. Give it to someone who isn't likely to actually use it... just kidding!



(Black Walnut - 11" x 2 1/4")