I too had a vacuum pump kicking around so I used the vacuum veneering to re-veneer my dash and it worked out great.
I had a local wood shop run the dash through their 36" drum sander to remove old veneer which left me with a perfectly flat and smooth finish. Unfortunately, he took a little too much off and I had to rebuild the thickness with some pine veneer before the final veneer layer.
I made my own vacuum setup with a length of the thickest PVC sheeting available at JoAnn Fabric. I forget the width but I had it cut about 18" longer than the dash. I used Vinyl pool repair adhesive to place 4" square piece of vinyl on the sheet to double the thickness to mount a bulkhead fitting through. I picked up some fittings at the local hardware store to create a bulkhead fitting for the vacuum hose. The next step is to fold the vinyl sheet in half and use the vinyl adhesive to glue two of the three edges together to make a bag.
For the veneering box, I used 2 pieces of 3/4 particle board to create a box. All exterior corners should be rounded with a router to prevent the box from damaging the bag. I think using the particle board plattens to exert pressure on the dash rather than just relying on the bag provides a better lamination. Make sure you tape wax paper to each piece of particle board to prevent the dash from sticking to it.
The veneering was done with Titebond III waterproof wood glue spread with a printer's brayer. You need to work fast since it sets quickly. Put an even layer on the veneer, position the veneer on the dash, place the dash in the veneering box and put the top platten (lid) on. Slide the whole sandwich into the bag. Fold over the end and clamp with a couple boards and some clamps. Pull the vacuum and let it sit for the glue to dry.
After lamination is complete, use an Exacto knife to rough cut the openings. Finish trimming the veneer to the opening with a dremel-mounted sanding drum. I used a small file to get the corners.
Finish with spar varnish since the spar varnish has UV inhibitors for durability.
Well, looking at the above, it is way too wordy. Rather than continue to bore everyone with the details, attached are some images of the setup. In hindsight, I probably should have taken more.
I hope this helps!
Ron W
71TR6