How do I create a vacuum seal around silicone hosing?

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How do I create a vacuum seal around silicone hosing?

How do I create a vacuum seal around silicone hosing?

Author	Message
Jess8bit	Jess8bit posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 133, Visits: 566	Hi Matthieu Watching your helmet tutorial, I've noticed you use a special composite glue spray. Could you please write down the reference ? thank you a lot
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Chris B	Chris B posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 5, Visits: 25	matthieutje65 (13/06/2013) you could also just drill them out, if resin hardened in the metal part Genius. I never thought of that. Thank you.
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Matthieu Libeert	Matthieu Libeert posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	you could also just drill them out, if resin hardened in the metal part Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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Chris B	Chris B posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 5, Visits: 25	carboncactus (13/06/2013) The problem is the resin which cures at a high temperature. Standard resin infusion is out the window since you can't use pvc tubing and vacuum connectors. At those temperatures, you have to use a silicone hose. Interesting. I never realized how much of a pain working at 350 F is (I mean, I can bake a cake at that temperature). The barbed fittings are a good idea. I may try that. I could probably get some mold release agent inside of it so that I can reuse them (assuming that the metal can withstand the chemical reaction).
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carboncactus	carboncactus posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	The problem is the resin which cures at a high temperature. Standard resin infusion is out the window since you can't use pvc tubing and vacuum connectors. At those temperatures, you have to use a silicone hose. You could try a couple of these: ^ ^ ^ ^ ^ tape tape hose tape tape Don't push the hose all the way in so there's space for the tape. I will ask this: Are you sure that it cures at those temperatures or is that a post-cure cycle? The other option is to wet lay then vac bag it as if it were a prepreg layup (using steel valves and connectors and silicone hose), but that defeats the point of VARTM. Edited 11 Years Ago by carboncactus
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Chris B	Chris B posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 5, Visits: 25	carboncactus: I thought of using a zip tie to wrap around the tubing and then adhering that to the gum tape, but I wasn't sure if the mechanical contact between the zip tie and the tube would hold a vacuum. The tubing is only 1/4" (6.35 mm) in diameter. Same idea goes for a jubilee clip; I'm not entirely convinced it would hold a vacuum. I'll see what I have lying around the lab and try it out. Matt: I did see that video from easycomposites, and I liked that vacuum connector. It seems a lot cleaner than what I'm doing. The only issue is that you still have gum tape wrapped around the seal between the silicone connector and the tubing, which leads back to the original problem of that I can't get the gum tape to adhere to the silicone tubing. Maybe if there was a way to connect the resin hose, do the infusion, then take the resin hose out without breaking the vacuum before throwing the part into the furnace.
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Matthieu Libeert	Matthieu Libeert posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	Thats how I do it for vacuum infusion skip to 5:54 min Easycomposites does it the same way (small difference is I pull vacuum all around the part instead of one part to the other Hope this helps you a bit more Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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carboncactus	carboncactus posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	Silicone releases naturally, so you'll have trouble sticking anything to it, even though it makes a good seal under pressure. Have you tried a jubilee clip or a thick cable tie to make full contact between the hose and the tape? The other option is a steel airline fitting with 1/4 bsp thread going into a nut, with another airline fitting on the other side of the nut. Sealant tape on either sides of the nut as a double barrier, PTFE in the thread. I can't see how that wouldn't seal. The only problem I see is the yellow tape going cheesy at 170C, although it should be good for 250.
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Chris B	Chris B posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 5, Visits: 25	I could do that, but I would still need to run the hose through the vacuum seal in order to get the resin in. Or are you suggesting switching to vacuum bagging? The epoxy system is made for VARTM and I'd prefer to use resin infusion to work with this. Also, the hosing doesn't have to be silicone rubber. If there's another material that will work, I'd be fine with working with that as well.
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Matthieu Libeert	Matthieu Libeert posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	I think the answer is simple... use a vacuumbag-connector and all your problems should be solved :p Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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