Author Topic: Vacuum Blanket  (Read 106762 times)

Offline mooseman

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Re: Vacuum Blanket
« Reply #30 on: December 23, 2011, 08:22:23 PM »
Try these guys, i worked for this company some years ago they make quality sealing products  you can buy small amounts through a distributors all around the country.
www.garlock.com
they also have an e-store
https://istore.garlock.com/OA_HTML/ibeCAcdLogin.jsp?a=b

here is a link to some interseting products

Premium Rubber
Premium grade elastomer (rubber) sheet products for applications where the low load requirements of rubber are necessary.

 http://www.garlock.com/ViewCategory?category=3#27

neoprene sheet   
https://istore.garlock.com/OA_HTML/ibeCAcdLogin.jsp?a=b

nitrile (buna) rubber
http://www.garlock.com/ViewProduct?product=185&region=1

epdm rubber
http://www.garlock.com/ViewProduct?product=575&region=1
mooseman
« Last Edit: December 23, 2011, 08:43:19 PM by mooseman »
DUE TO CIRCUMSTANCES COMPLETELY WITHIN MY CONTROL YOU SHOULD GET YOUR OWN TEE SHIRT AND A SHARPIE MARKER BY NOON TOMORROW OR SIMPLY CALL SOMEONE WHO GIVES A SHIRT.


Offline ZooCity

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Re: Vacuum Blanket
« Reply #31 on: June 12, 2012, 07:15:38 PM »
Wanted to post on this sticky thread that I agree with those who say 'get the right blanket and forget about it' but I was quoted at $1395 from Millington and Douthit is at about the same.  Holy geez.  It's a rubber blanket...right?  Or am I missing something here?

We do have a larger unit at 66x54 and pricing is by the square inch.

The bummer is I need to find a roll that wide if I want to try neoprene. 

Is patching not an option on the rubber?  Because I'm ready to explore it. 

Offline Prosperi-Tees

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Re: Vacuum Blanket
« Reply #32 on: June 12, 2012, 07:17:42 PM »
Was that a typo? Holy cow!

Offline JBLUE

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Re: Vacuum Blanket
« Reply #33 on: June 12, 2012, 07:32:53 PM »
Wanted to post on this sticky thread that I agree with those who say 'get the right blanket and forget about it' but I was quoted at $1395 from Millington and Douthit is at about the same.  Holy geez.  It's a rubber blanket...right?  Or am I missing something here?

We do have a larger unit at 66x54 and pricing is by the square inch.

The bummer is I need to find a roll that wide if I want to try neoprene. 

Is patching not an option on the rubber?  Because I'm ready to explore it.

I patched ours with weather strip cement and a piece of inner tube. Worked pretty good until it started failing in other spots.  A new blanket for our NuArc is 5 bills and for a little more I can buy the whole assembly and get a new frame and seal. That rubber is expensive.
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Offline ZooCity

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Re: Vacuum Blanket
« Reply #34 on: June 12, 2012, 07:36:28 PM »
Was that a typo? Holy cow!

Nope.  I had to have the guy repeat it a couple times on the phone.  Douthit's rate at this size is about 33 cents per sq inch, similar price.

I'm okay with paying for the right stuff but sweet lord I payed anywhere from $0-400 for this thing depending on how you look at it.  Figured I'd have a few hundo in glass, maybe some parts and a few hundo in the blanket to recondition it.

Offline screenxpress

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Re: Vacuum Blanket
« Reply #35 on: June 13, 2012, 12:07:14 AM »
I was just surfing around and found this. 

http://www.gpiparts.com/prod51.htm

No idea of pricing, etc.....
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Offline ebscreen

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Re: Vacuum Blanket
« Reply #36 on: June 13, 2012, 01:44:38 AM »
Go for the rubber Zoo. I used to use pond liner on a huge Douthitt from like 1942. No problems, worked great, lasted a hell of a lot longer than neoprene. 30  inches of mercury is 30 inches of mercury, no?  Not to mention I've heard talk of less vacuum actually being better for film contact....


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Offline ZooCity

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Re: Vacuum Blanket
« Reply #37 on: June 13, 2012, 11:56:12 AM »
What type of rubber exactly though?

I found silicone vacuum blankets though they all appear to be milky white and not dark and may hold too much heat perhaps?.  I'm sure there's a variant though with cloth or something, it looks like other industries need and use elastic, durable vacuum blankets for tasks far more demanding than contacting film positives to screens.  I think I might just call a couple rubber suppliers, tell 'em what I'm trying to do here and get a product recommendation that comes on the right width of roll. 

For those who buy oem blankets, what value is added to the blankets you get from the frame mfg's to justify that cost?

Offline alan802

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Re: Vacuum Blanket
« Reply #38 on: June 13, 2012, 12:06:07 PM »
I got priced around 900 for a blanket and I went to foamorder.com and got it for 1/10th of the price that a screen printing supplier was wanting.  It might not be as good of blanket as the one that came on our unit, but it's lasted 2 years without any sign of wear and tear, I would advise nobody to pay a supplier for a blanket when they can get a neoprene replacement for pennies.
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Offline JBLUE

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Re: Vacuum Blanket
« Reply #39 on: June 13, 2012, 12:14:10 PM »
Mine finally let go and the manufacturer was 2-3 weeks out to replace the whole frame. I had to get some neoprene from a supplier out of San Francisco. It does not put the kind of pressure down the factory blanket did so I just threw in a 3 in thick foam block with black fabric and I have not had any issues yet. I have ran a couple of dozen sim jobs through it with no loss of dots on the screen so until the seal goes I think I am going to stick with it.
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Offline ebscreen

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Re: Vacuum Blanket
« Reply #40 on: June 13, 2012, 12:22:05 PM »
Pond liner. I believe it's EDPM. Probably $10 for your frame.


I would assume the benefits of Neoprene to be that it has more squish (technical term)
to it and would conform to any irregularities better. Even microscopic ones. I could
be entirely wrong on this though.

The benefit of purchasing the exact blanket from a supplier is that it is cut to size and likely
ready to plug and play with your exposure unit. No trimming or anything. I personally
am at the point in my career that "buy the damned thing and be done" is my mantra.


A thought just came to mind. My Douthitt contact frame came out of an offset shop (Dharma Publishing)
and I had to modify it to work with screens as opposed to plates as there wasn't enough clearance
to get a screen in. (common problem when trying to convert these units)

The original "blanket" was a super heavy stiff canvas. Kind of like Army tent material but even stiffer, no flex.
Granted, plates are paper thin and flat, so they wouldn't need the blanket to conform around any contours,
but, they certainly do need good contact, a darn sight better than us any way.

So, ten bucks says neoprene is used as it can get around and in the screen profile tight. But, unless you
are exposing images that come within an inch of the frame (you shouldn't be) you don't need that.

Two cents over.

Offline Frog

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Re: Vacuum Blanket
« Reply #41 on: June 13, 2012, 12:42:21 PM »
Also, the stretchier the rubber, the closer to the edge of the frame your screens can go (so, bigger screens or more screens)

That rug really tied the room together, did it not?

Offline ebscreen

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Re: Vacuum Blanket
« Reply #42 on: June 13, 2012, 12:50:51 PM »
I was able to do two 25x36 Newmans on the Douthitt.

But like many others, I found that we were rarely shooting the same mesh/EOM
etc. And stopping mid exposure to pull one screen and continue with the other
invites far more variables than blanket material.


Offline ZooCity

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Re: Vacuum Blanket
« Reply #43 on: June 13, 2012, 01:18:01 PM »
Yeah, I'm not sure we'll gain any efficiency with the large frame over our homebrew unit, it will likely slow us down for the 25x30 screens.  We will gain the ability to shoot the big flatstock frames though.  It may well turn out that I only use the frame for these big ones, wheeling it out as needed and shoot our textile screens on the current setup.  We have two complete Olec 5k units and it shouldn't be impossible to set one on a shelf to shoot the big glass and simply plug in whichever one is needed. 

I'll check out pond liner after I call some sheet rubber suppliers today, good to hear it works.  I feel like some patches might work fine too if it's not totally fubared.

Thanks all for input, will post up when complete.

Offline Chadwick

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Re: Vacuum Blanket
« Reply #44 on: July 07, 2012, 04:51:25 PM »
I use a nuarc at work.
We use the 'stock' replacement blankets, very expensive stuff, unfortunately.
I've replaced a few blankets over the years, some due to normal wear, more due to operator negligence.

You want to have about 4-5" of sag in the center when installing it.
You want the rubber down, cloth up. They are designed this way for a reason.

What they don't tell you, is that after you fubar your first blanket,
( and it works best if you use actual vac blanket material for this, rubber side down )
you should cut strips out of it, about 4" wide ( depending on frames used ) and overlay the frame of your screen with them while exposing.

In my defense, I used to use some scrap polyester material for this, but it wasn't as effective.

So, in my case I have two long strips, and two short strips, about 6 inches of overhang past the frame edges.
Latest blanket doesn't have the slightest sign of wear on it, and it's been through the mill already. Works like a dream.

Only issue, is that you have to find the sweet spot for placement, because, it can cause a bad seal if not laid properly...
I know that probably doesn't help much, but if you're doing it, you'll see what works and doesn't very quickly.
The beauty of using vac blanket material though, is that it is very flexible, provides a good seal,
and allows your actual blanket to suck down as tight as it would be by itself, if you place everything proper.

Wish someone would have told me this years ago, so, there you go.

Throwin' copper.
Hope it helps some of you.
Cheers.