Since the top only needs some adherence to keep the two pieces of mdf
together, I wasn't concerned that the glue was even or that there was
squeeze out. I just drizzled the glue on and did a quick spreading with a
putty knife. I put on the top and found that as soon as the two pieces went
together, it was like I used contact cement. It wouldn't budge. I had a
very small gap at a place or two, but it was negligible as far as the top
went. Also, I applied plastic lam to all sides. If you apply glue, let it
dry, then apply another coat before putting the two pieces together (as
another poster mentioned), it will give you time to apply clamping cauls.
Make one piece the correct size and the other oversize, then trim it flush
later with a router.
For my next router table, I will build a really sturdy frame, sort of like a
torsion box, that is mortise and tenoned with four crosspieces (allow room
for the router). Then I will apply one layer of mdf to this. I believe
this will stay flatter longer than two layers of mdf over time. Of course,
care must be taken to make the frame flat at glue up.
I am in the process of constructing a router table using ¾" MDF for the case
and tabletop. The case was completed with little problem or fanfare. I cut
two sections for the top and spread PVA glue over the surface of one of the
panels. I tried to spread the glue evenly with a spatula and had difficulty
spreading it. To further complicate matters it appeared the MDF was
absorbing the glue. I opted to drizzle glue over the remainder of the piece
(about ¼ of the area) and let gravity help spread the glue. I assumed (big
mistake) that the glue would spread out when weight was applied on top. I
stacked two coolers filled with water on top and placed the cabinet case
atop of that. I then put a couple of boxes of ceramic tile on the case for
good measure. I knew I was in trouble when I saw glue being squeezed out
sporadically around the pieces. After letting it dry 2 days I uncovered the
mess. As I feared there is a gap on one side where the glue did not spread.
I now have a new top for my yet to be built SCM station!
Now I have to do it again. I have thought about using a paint roller to try
to evenly coat the panel. Has anyone tried this method? Any other ideas? I
have considered trying more weight but shy of parking a car on it, I don't
have a clue what I could use. Again, any Ideas?