Enough people have asked, and I was installing a new headliner, so I took some pics making some new pinchwelt.
Supplies:
Vinyl
3M Super 90 (or 77) spray adhesive
Foam rubber welt core OR caulking backer rod
Scissors
First, cut a strip of vinyl about 4" wide and as long as the piece of welt you need. The strip doesn't need to be straight, you can have as small as about a foot radius turn and it will still pinch together fine, vinyl is stretchy. Spray the vinyl liberally with 3M adhesive. The front lawn is a good place to spray the adhesive as any over spray gets mowed away next time around.
Once the spray adhesive has flashed (about two minutes in the sun), lay the welt core in the center.
You can buy bare foam rubber welt core at upholstery supply houses for a buck or two a foot. It is great stuff.
A much cheaper alternative, and one that, in my opinion, works just as well as traditional foam rubber core, is backer rod. Backer rod is used to fill large deep cracks before caulking to save caulk. It is found at any hardware store and costs about $2.50 for 20 feet. One difference that I think is worth mentioning is that backer rod is closed cell foam and will not absorb water, while foam rubber core is, in fact, sponge.
Pinch the vinyl together, taking care to pinch tightly right up next to the welt core. Now you know why it's called "pinchwelt".
When you are done you will have xxx number of feet of pinchwelt. You can buy reproduction pinchwelt from any classic car vendor, but it's about $3.00 a foot. The Falcon wagon uses about 20 feet. I had a lot of left-over vinyl from the seat covers and dash pad, so my main $$$ outlay was backer rod, $5.00 for two bags, and I always have a few cans of 3M adhesive on hand. You should be able to make 25 feet of pinchwelt in less than half an hour, even if it's your first try.
The repro pinchwelt is cloth covered and looks like crap when new, and good luck on color matching. Making your own with matching vinyl looks many, many, times better.
The Falcon needs to have about a 5/8 of an inch of flap to tuck up under the trim strips and clamps. I trimmed by eye, it's not brain surgery.
Clamps squeezed, trim strip installed.
On the '60s era Ford cars that had trim strips, these little twist tabs hold them in place. They fall out, and instantly vanish into thin air if you don't tape them in place.
Another important thing is to measure before you start quaffing the cold beer on the hot day you install the welt. This way you don't end up with an extra four feet of pinchwelt.
