vac top, my next project...

[Shawn (EIP)]

Found this, looks pretty easy to me... (click on all the bold lettering for pics) or here
http://www.flickr.com/photos/48428440@N04/sets/72157623645144972/

http://www.gigposters.com/forums/screenprinting/150205-diy-exposure-unit-vacuum-top-under-20-bucks.html

[tpitman]

I think I've posted this before. Wood frame with pond liner from Home Depot . . . butyl rubber as far as I know. Looks and smells like an innertube. Funny thing is, the woman in garden read off the wrong ticket and charged me for weedblock instead of pond liner. A sheet big enough to do 3 units cost me about $5. I used aluminum strips, drilled and screwed over the liner and frame edge, and used self-adhesive round weatherstripping for the seal against the glass. The red circle shows the hole where the barbed hose fitting screwed in.

[Gilligan]

That's the right way to do it.

BUT... the Gilligan way to do it is with a space saving vacuum bag.

http://www.t-shirtforums.com/screen-printing-equipment/t159932.html

Working very well so far, I've heard with aluminum frames that very tiny barbs can cause micro pin holes in the bag.  You can just run the vacuum constantly if this happens... which is the same way you have to run a vacuum top on a exposure unit anyway.

[Shawn (EIP)]

That's the right way to do it.

BUT... the Gilligan way to do it is with a space saving vacuum bag.

http://www.t-shirtforums.com/screen-printing-equipment/t159932.html

Working very well so far, I've heard with aluminum frames that very tiny barbs can cause micro pin holes in the bag.  You can just run the vacuum constantly if this happens... which is the same way you have to run a vacuum top on a exposure unit anyway.

Your idea is witty and crafty but if you have 12 or so screens to burn a day that's gotta be costly time wise not to mention keeping the bag free of screen frame crud.

[Gilligan]

True... granted my bag is pretty spacious on the 20x24 frames and I found bags that were larger.

But you are right... in a full production shop it is unreasonable.  I did have plans for a real vac top unit to build... but it was just one more hurdle sitting in my way.  At this point I'm "up and running" but not certainly not in a real stride of a full production shop.  I can now attack this hurdle when that time comes a lot more comfortably than I was handling it.

[Shawn (EIP)]

heres a pic of my unfinished unit, the vac top has been put off for 2 or 3 years now

The glass and glass frame came off a plate maker that a printer was throwing out , the unit was too heavy so I built a new frame then picked up a metal halide lamp off craigs list for 50 bucks.

[jsheridan]

Ive got a Lawson exposure and the vacuum motor is nothing more than just that.. a vacuum motor and the top is neoprene. It draws down perfectly.
The problem with the pool or shower liner is its not flexible enough and won't wrap around the frame completely.

[tpitman]

The pond liner won't pull into the tight corners of the frame, but with slack built in it will pull most of the open area inside the screen where the art is tight against the glass. Repairs are also easy and the stuff isn't prone to tears anyway. Not to say that a neoprene blanket isn't best. I know in my store-bought unit I protect the neoprene from the corners of the frame with thick pieces of dense foam rubber. Not interested in buying a new blanket before I have to.