Making Your Own Plywood

[Tapper]

Nice job, John as always. You have a couple shots of the final product? I may have to break down and finally get a vacuum bag setup.


Doug

[jteneyck]

Nice job, John as always. You have a couple shots of the final product? I may have to break down and finally get a vacuum bag setup.


Doug

Not of these panels yet, but here's one of some 8 mm walnut plywood I made for the wall clock I made last year.  Again, 5 plies, all walnut in this case.  



If you look closely, you can see the plies on some of the parts in this photo:



The vacuum bag is home made.  I used 30 mil vinyl and glued the seams with PVC pipe cement.  You can make any size you need and for a lot less money than buying a bag.  That bag is now almost 30 years old and I've made hundreds of pressings with it.  I made another bag more recently and used 20 mil vinyl for increased flexibility.  Polyurethane has the best flexibility but the price of commercial bags is more than I care to spend.  

You don't need to spend a lot on a vacuum pump or pump control system either, though some do.  I use a Gast vacuum pump with about a 2 cfm capacity that I got used for less than $100.  The "control" system is nothing more than an on/off timer that cycles the pump often enough to maintain the vacuum above about (really less than) 18" Hg.  If you use Titebond type glue you don't need any control system.  The pumps are made for continuous duty, and you only leave it in the bag for a couple of hours until the glue sets.  With Unibond 800 or epoxy which take longer to set, however, I use it to reduce the wear on the pump.  

A vacuum bag system opens up a host of new opportunities, from easily making bent laminations, to veneering, whether using commercial veneer or shop sawn.  

John

[mound]

The vacuum bag is home made.  I used 30 mil vinyl and glued the seams with PVC pipe cement.  

Where did you source the vinyl?

[jteneyck]

Where did you source the vinyl?

The first time from McMaster Carr.  The second time from my local boat canvas maker, who was substantially cheaper.  If you decide to make a bag, regular PVC pipe cement works as well as the special stuff sold by Joe Woodworker.  Do not use the cleaner first.  Just wipe the seam with DNA to clean it, let it dry, and then smear on the cement with the dauber.  I don't know why it doesn't work as well with the cleaner first, but that's what I found.  

John

[jteneyck]

Bonus photos Doug.  Here are the cherry/ash plywood panels.  3/8 and 1/2" with 5 layers:



3 mm and 1/4" with 3 layers:



John