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Jay-J Newbie
Joined: 19 Jun 2011 Posts: 17 Location: US
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Posted: Sat May 25, 2013 4:54 pm Post subject: Negative mold metal tubing |
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Does anyone know where to get the very small tubing that is placed into negative molds that allows the air to be evacuated? I've only seen it in pictures but it looks just like the tubing used in a syringe, only much longer and cut to the needed lengths. I don't even know what the stuff is called, maybe if I can find out what it's called I will have better luck finding it. Thanks! |
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jdougn Guru
Joined: 18 Mar 2009 Posts: 714 Location: Louisville KY area
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Posted: Wed Jun 12, 2013 8:18 pm Post subject: |
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Where did you see the tubing? There are probably other ways to get that done without tubing. _________________ DougN - Just in case you're wondering, I got my "rating" legitimately... by posting aimless drivel, useless advice, and pointless questions. |
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Jay-J Newbie
Joined: 19 Jun 2011 Posts: 17 Location: US
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Posted: Thu Jun 13, 2013 3:09 pm Post subject: |
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I saw it in some pictures on smooth-on's website. They were showing the process of making a negative vacuum mold using one of their products. I ended up finding the tubing on McMaster, it's called hypodermic tubing in case anyone else needs to get some. |
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jdougn Guru
Joined: 18 Mar 2009 Posts: 714 Location: Louisville KY area
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Posted: Thu Jun 13, 2013 3:46 pm Post subject: |
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Jay-J wrote: | I saw it in some pictures on smooth-on's website. They were showing the process of making a negative vacuum mold using one of their products. I ended up finding the tubing on McMaster, it's called hypodermic tubing in case anyone else needs to get some. |
I'd be real interested in seeing the negative mold you're building! _________________ DougN - Just in case you're wondering, I got my "rating" legitimately... by posting aimless drivel, useless advice, and pointless questions. |
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Fredo Master
Joined: 21 Mar 2007 Posts: 251 Location: Kingdom of Nye Area 51
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Posted: Thu Jun 13, 2013 5:28 pm Post subject: |
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What you saw on Smooth on was vacuum infusion. The bag is over a layup of fiberglass or maybe carbon fiber cloth.. The bag is sealed to the sides of the mold and is pulled into it... Those tubes are between the fiber cloth and the bag.. The air is evacuated out through the small tubes and a resin is drawn in by the vacuum on the opposite side. The evacuation tubes are pulled back so they aren't trapped between the bag and fiber.. It's a far cry from vacuum forming..... More like vacuum pressing.. Here's a site for vacuum pressing, bagging and clamping. I've bought a bunch of stuff from there over the years.. http://www.veneersupplies.com/categories/Vacuum__Press__Items/Vacuum__Bags/ Lets see some pictures.. _________________ If someone has a gun and is trying to kill you,
it would be reasonable to shoot back with your own gun...The Dalai Lama..Seattle 2001 |
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Jay-J Newbie
Joined: 19 Jun 2011 Posts: 17 Location: US
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Posted: Thu Jun 13, 2013 5:55 pm Post subject: |
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Hi Fredo, I know what you're talking about but that's not what I was referring to on smooth on's website. Here is a link to the article where the tubing I'm talking about was used...
http://www.smooth-on.com/gallery.php?galleryid=190
The mold that I'm making isn't a negative mold exactly. It's a positive mold that has a valley between the high point and the low point. The valley creates a pocket of air which can't be evacuated unless there are little holes going down through the mold where the valley is. I'm experimenting with making molds out of concrete and there is no practical way of drilling little 1/16" holes through concrete so inserting the tubing is the best option in my opinion. I haven't made the mold yet so I don't have any pictures. Does that make sense? |
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gellfex
Joined: 02 Nov 2010 Posts: 4
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Posted: Tue Jun 18, 2013 10:13 am Post subject: |
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I don't think they're tubing, more likely rods or music wire that have been released, they're pulled out after the resin sets. |
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jdougn Guru
Joined: 18 Mar 2009 Posts: 714 Location: Louisville KY area
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Posted: Tue Jun 18, 2013 10:19 am Post subject: |
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Have you tried experimenting with something like weed whacker line or similar? I wonder if it were coated with car wax if it would pull right out of concrete. Holding it in place might be a challenge.
dn _________________ DougN - Just in case you're wondering, I got my "rating" legitimately... by posting aimless drivel, useless advice, and pointless questions. |
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Fredo Master
Joined: 21 Mar 2007 Posts: 251 Location: Kingdom of Nye Area 51
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Posted: Tue Jun 18, 2013 2:25 pm Post subject: |
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Spektr once posted about using mono filiment line in gravel filled face molds for air ways... I think there's a good chance the mono will stretch and become smalled in dia. helping it release. Oil is a good release for concrete.. A thick grease might even be better on the small dia. line.. _________________ If someone has a gun and is trying to kill you,
it would be reasonable to shoot back with your own gun...The Dalai Lama..Seattle 2001 |
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