On Fri, 25 Nov 2011 18:14:14 -0600, Swingman wrote:

On 11/25/2011 5:03 PM, Wilfred Xavier Pickles wrote:

I just made a table saw sled using 1/2" MDF for the base.

MDF is very prone to expansion from moisture. I have some Minwax Polyurethane.
Suitable to seal the MDF? Just around the edges, or all surfaces?

Shellac, right out of the can, works well also. It's what I use, but I
usually have some used tins laying around.

Johnson's Paste Wax will also work and is much slicker than either poly
or shellac, unless you wax them.

Also, tell him to stop washing his sleds in the dishwasher.

--
Progress is the product of human agency. Things get better because
we make them better. Things go wrong when we get too comfortable,
when we fail to take risks or seize opportunities.
-- Susan Rice