Vacuum Frames---Minimum size in relation to screens.

[Frog]

How much clearance? What's the closest to the vacuum frame one can go? In other words, how much smaller than the vacuum frame does a screen have to be? Or, can you still get decent contact in the center of a large screen that barely fits.

[killergraphics]

Over the years the ones I have used seems to be something like 4".
But like you would tell me try it and see what happens or you can always use the foam.
Works almost as good.

[Preston]

How much clearance? What's the closest to the vacuum frame one can go? In other words, how much smaller than the vacuum frame does a screen have to be? Or, can you still get decent contact in the center of a large screen that barely fits.

Depends on the material used for the blanket and how tight it is. If it is EPDM then I would make the frame about 8" bigger than the largest screen and that will give you about 4" all the way around. If it is soft neoprene you can get away with it being closer.

[Frog]

That's good info, and about what I figured, but I'm still curious as to what happens when one has, say a mere 1 or 2 inches., not enough for the rubber to seal against the glass?

I'm wondering if it would merely take longer to pull a vacuum because the space will be larger, but still suck down in the center? Does the blanket absolutely have to seal around the frame on the glass?

[killergraphics]

Man its ruff being right all the time

But its like my X when you ask it to do something it was not designed for...
there will be repercussions.

In this case just a tar in the blanket.

[Preston]

Does the blanket absolutely have to seal around the frame on the glass?

No. As long as the blanket is sealed across the area of the screen where the film is then you should be fine.

[3Deep]

Andy my unit has a 24x26 lid which I can fit a 20 x 24 screen in and I have about 1" on each end and it sucks down great (neoprene blanket) its a Prolight 1 unit. My advice if your buying or building a new unit get it large enough for atlease one 23 x 31 frame or two. I will be getting a new unit myself of that size in the near future burning two screens at a time would be great plus I could burn the larger 20 x 28 frames.
Darryl