Made a 24" by 24" Vcarve file for a Vacuum Jig with just one gasket that will handle something flat 24 by 24. My plan is to carve this out this week in some PVC trim board from the local box store. I will glue up 4 pieces of this pvc siding trim to get a 24" wide piece. Then carve it out using the pod file that has all of my vacuum pods in the one file. This includes the toolpaths using layers and sheets.
What are you going to use as an adhesive? Just be aware that certain types of plastic need more specialist adhesives & PVC is quite a general term so, not sure what you are using for this. Where ever you are buying may be able to help with what to use
Did you find out if the PVC you are using is porous at all? Just be aware that if it is then the larger you make the vacuum hold down the lower the vacuum you will be able to maintain. The good news is that with a sheet at 24 x 24 you won't require a large vacuum to hold it down
After a week of testing and working with it. I found out that HDPE is the better choice. It's a bit more expensive but when you add in the glues and the sealers to this project the HDPE at $67.00 for a 3/4" x 24"x 24" is a better value.
The PVC Trim boards have a varying rate of allowing vacuum air measured in inches of mercury between them. After sealing the board very much like one would do with HD MDF it holds 22 to 26" of mercury at the vacuum inlet on the jig board. Here is a youtube video on the learning process. Vcarve processes made machining this board very easy
