I want to make a sled with t tracks in it for rips on my table saw. Ideally 1/2" thick if material permits. Max 3/4".

I want it to never warp or twist. I also want the edge to be durable since it will be sliding along my fence. I live in an area where humidity varies greatly daily.

The only choices I've considered so far are plywood, MDF, and delrin.

I see my plywood warp regularly. My MDF also temporarily warps on humid days, where one side dries back out faster, plus the edges of mdf seem to fray a bit with wear. Delrin is really expensive, $80 USD for a 2' x 1' x 1/2" sheet.

What should I use? What cost effective and easily machinable material can I use for a warp-free, durable sled base?

  • 1
    im 100% sure this has already been covered. Just have to find it. Baltic birch plywood and MDF are the go to's. MDF does fine in humidity but does not like direct contact with water. Duplicates are Ok. We like then as they can guide people to the right resources.
    – Matt
    Nov 14 '15 at 22:07
  • @matt Looks the same to me. But I don't understand my MDF/plywood problems. I'll ask in comments over there. Thanks.
    – Jason C
    Nov 14 '15 at 22:11
  • You could ask your concerns about MDF/Plywood humidity in a separate question if that is what you are really looking for.
    – Matt
    Nov 15 '15 at 1:31
  • In your case plywood is vauge since there are many kinds.... however they are chosen for their dimensional stability so I wonder if you are working during a typhoon. Where is the warp? along the edges? are there gaps in the veneer?
    – Matt
    Nov 15 '15 at 5:12
  • @Matt for plywood its usually a gentle curve across the entire thing. For MDF it varies. I see plywood warping up to 3/4" thickness. MDF thicker than 1/2" seems stable. The range of temperature and humidity here is large and rapidly changing this time of year, a 70F 50% afternoon can be 45F 90% by evening. Either that has something to do with it or I keep buying crappy materials. The cheaper plywood sometimes has voids inside between panels in a layer, the pricier birch stuff never really does. I want something that I can buy/mill straight and that never changes.
    – Jason C
    Nov 19 '15 at 23:31