MDO for a miter sled?

[Alex Zeller]

I'm going to make my own version of the Incra Miter express sled for my table saw. My plan was to go with something like Baltic birch but I've found a cement supply store that carries MDO (also called sign board) for about the same price. Is there a downside to using over regular plywood? I would think the MDF faces would resist chipping and impacts better than birch. Also being very water resistant if something bad was to happen it could get wet without being damaged. It's been decades since I used the stuff but I remember it being very flat.

[Paul F Franklin]

I use MDO for all my jigs and fixtures and sleds and recently built three shooting boards using it for the base that the plane rides on. Uniform surface, flat, smooth and somewhat slippery. Very slippery if you wax it. That could be a disadvantage in the cases where you want a little bite to the surface to prevent slipping; BB would be better in that case. The other advantage is that it's readily available in 4x8 sheets. If you are buying the concrete forming type I think it's available in 4 x 10 or even 5 x 10. I know BB is available in 4x8 sheets but the 5x5 are a lot more common near me.

I think of it as kind of halfway between BB and phenolic plywood.

[Dick Mahany]

I've used MDO plywood for jigs and sleds. It is excellent. The sled below was built from 3/4" double sided MDO ply but it was heavy due to all of the accessories and the 3/4" material, so it got used less than I had planned. The material was stable and I wouldn't hesitate to use it again for a sled in 1/2" material. Very flat and durable . I never waxed mine as it glided easily with factory faces.

MDO sled.jpg

[Steve Eure]

Wow Dick. That's one impressive sled you have there. Did you design that yourself?

[Dick Mahany]

Wow Dick. That's one impressive sled you have there. Did you design that yourself?

Steve, I saw a picture of that sled somewhere in cyberspace and fashioned mine after that. I believe the designer called it a "super sled" or similar. It did do just about everything, however for simple crosscuts and accurate miters, I made smaller, much lighter dedicated sleds which got used more frequently due to simplicity and ease of handling. I always used MDO because it worked so well.

EDIT: Found the link for the sled at Eagle Lake Woodworking (from about 10 years ago) : http://www.eaglelakewoodworking.com/...iter-Sled.aspx

[Alex Zeller]

Thanks for the replies. I'm going to use it for accurate cutting of small wedges so I'm going to incorporate my Incra 1000HD miter into it by adding a miter slot. I haven't decided if I'll just add slots for a hold down or put an aluminum T-slot track in it. But it sounds like 3/4" MDO should work well.

[Tom Bender]

Mine is 3/16" luan plywood and is one sided. The runner is Oak and the fence is Basswood. The light weight and grippy surface are big advantages. I can put it on and off while holding a cold beverage in the other hand.

[Peter Kuhlman]

Where is the darn LIKE button???????