i have a Sheet of 18x18" aluminum sheeting that i will have
to drill hundreds of tiny holes into to allow the air to pull though!
also i will the contructing the Vacuum box this week, using
2x4" timber. i have come up with a different idea for the moulding
frame and will share more on this once i have built it.* **
Um, ya know perfboard has lots of tiny holes already drilled for you, comes in varying thickness and with different hole sizes and hole pitch.
If you are not looking for really fine detail you can even use pegboard, which is how I pull canopies and swoopy parts for my planes… and what the guy did in his video, heh.
I think you will find that unless you are attempting to do very complex parts that the time spent doing finish work on your plugs will far far and very far have a much greater impact on your results than lots and lots of holes that you have to plug most them of up anyway. I would simply suggest, based on my experience, that you make a simple fixture and try pulling a few shapes before sinking lots of time into trying to make a professional grade vf machine. I have found the peg board vs. perf board (0.042" holes on 0.156" pitch grid, my vf box can drop in different surfaces) to make very little difference unless I am doing small parts where the number of ports is restricted, or where I have many changes in direction along the edges. Spending hours finishing a cannopy or cowling plug, wet sanding the 7th or 8th coat of poly with 1600 grit paper, is what really defines how nice it is going to look when finished. Also having a hot air gun like the type used to heat shrink covering on r/c planes is a big help on big parts where the plastic cools before it has had time to fully form around the bottom of the plug.
GL.