movement of corian, to be used on bies fence

[cody michael]

from my researche a 42 inch piece of corian moves 1/16 inch over 100 degree temperature differnce. can I screw this to the metal tube of the fence? or do I need to make the holes slightly big etc

[Bill Orbine]

You are going to experience a 100 degree temperature difference in your shop? Let's not forget the expansion rate of the steel fence. I say just screw the on and not worry about it.

[cody michael]

from winter to summer yes, it can get to around 100 degrees in summer -15 or so in winter

[Jamie Buxton]

Why use plastic on your fence? Why not use wood? Would you make a dining table with corian? Why put it on your table saw? Wood is nice to work with. Plastic is well, plastic. Ick.

[Bob Grier]

I think it is best to allow plastic to move because I don't know whether the stress caused by the plastic would strain the fence. However, if the temperature changes slowly enough and the plastic is not too thick, the plastic will stress relieve without causing a problem with the metal fence. If the plastic is even thinner, then the plastic would probably strain (change shape) before causing strain of the metal fence. Number or spacing of attachments would influence reaction. I don't know what thin enough is and I can't help you, however, consequences of having a problem are minor so if a problem develops, then you can make a change to address the problem.

If plastic is thick and fixed to metal and temperature changes fast like if you heat the shop from -15 to 70 for the day, then you will have a problem. If temperature changes slowly and plastic is thin enough, then you probably won't have a problem. If you make it so the plastic can move then you won't have a problem.

[Dick Brown]

Had Corian on my saw fence for several years now. Never saw any indication of distortion from temp changes. Mine is screwed tight to both sides of the steel tube. I agree with Bill on the tube expanding also but maybe not as much as the Corian. I used to have a chart for steel expansion x temp when I worked with steam boilers but that was a long time ago. I am sure you could Google for one. If I were you, I would put it on and if there were a problem, ream out all but the center hole about 1/16 so it would stretch both ways from there. Looks like 1/32 inch each way from center of your 42" fence would be it's attempted movement, worst case scenario, less any steel expansion. If you have a 100 degree temp swing in your shop, screw it on when the temp is about mid-way and cut your movement to half of that. With the steel movement entered in, You are getting down to splitting frog hairs. As far as Bob's point about stressing the tube, any stress will be canceled out by the other side if it you put Corian on both sides.

[Curt Harms]

If there's no down side to making the holes slightly oversized, I'd do that just for peace of mind.

[Tom M King]

Corian machines nicely with woodworking router bits. If you don't want to buy a special stepped bit (don't remember exactly what they are called, but there is one especially for this purpose) you can do the same thing with a couple of different sized router bits. One to cut a small slot for the screw shank, and the larger one to recess the head.

[Phil Thien]

Wow, I had NO idea Corian moved that much.

[Tom M King]

It was a complicated name to remember, but I found the "Screw Slot" bit: http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bit_screw_slot.htm

Go slow and be careful with it. I broke the first one I bought, being so used to high quality Whiteside bits.

[cody michael]

I made the screw a decent amount oversized so hopefully it will work out okay. I mounted the corian to the fence today, it wasn't as flat as I had hoped for, I shaved a little 0ff each end with a card scraper, and put a few folded pieces of tinfoil as shims in and it is close enough for me. With a straight edge on it, I cannot get a piece of thin magazine paper to slide in between straight edge and corian