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Old 05-11-2017, 05:44 PM   #11
Hanaldo

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A resin brake is exactly that, an area before your vacuum side with no flow mesh, only a material like peel ply or breather cloth. The idea is that the resin can't flow quickly through these materials like it can through the mesh, and so it hits the brake zone and slows dramatically. This gives the rest of the laminate a chance to catch up to the flow front before you start sucking resin out; or in the case of using MTI hose it gives the laminate a chance to completely wet out before the resin reaches the MTI hose and seals it, stopping any trapped air from escaping.

You have to remember that the resin flow through the laminate is staggered. What you see from the top is slightly delayed on the laminate surface, depending on how thick your laminate is and what materials are in the stack. So the flow front you see on the top is slightly ahead of the resin flow underneath, and if your top flow front reaches your MTI hose before the 'bottom' flow front, then you will be trapping voids in there that are likely to be present on the surface.
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Old 05-12-2017, 04:57 AM   #12
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Quote:
Originally Posted by nickwad View Post

No I did not have a resin break , could someone explain what that is or point me to a thread covering it please.
A resin break is on the far left side of this part. It is just, in this case, about 50mm of peel ply between the part and the vacuum hose. This part is 600mm long and infused perfectly in about 25 minutes.


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Old 05-12-2017, 06:19 AM   #13
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Thank you for the info I will try with a resin break.
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Old 05-14-2017, 08:50 AM   #14
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yes, great explanations of the purpose. Thanks guys
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Old 05-17-2017, 05:20 PM   #15
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Quote:
Originally Posted by nickwad View Post
Thats great to hear ! is there a thread for your build ? i still have a garden full of jet skis ! lol but am working on a motorised surfboard project at the moment.
Nickwad, here is a thread of my latest ski. It's actually the 2nd generation as the 1st generation was just to learn from. Haha http://www.x-h2o.com/index.php?threa...carbon.167702/
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Old 06-05-2017, 04:51 PM   #16
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Nickwad, here is a thread of my latest ski. It's actually the 2nd generation as the 1st generation was just to learn from. Haha http://www.x-h2o.com/index.php?threa...carbon.167702/
Awesome work mate ... blown away !
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Old 11-08-2017, 01:36 PM   #17
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Originally Posted by hojo View Post
I would try ending the mesh short by 25-50mm. This prevents the resin from overflowing and trapping air. Otherwise the resin flows right to the MTI hose and cuts off the vacuum before all the air has been removed from the laminate
Hi,is it the same thing if you don't use MTI?
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Old 11-08-2017, 01:48 PM   #18
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Quote:
Originally Posted by nickwad View Post
I am having a recurring problem of air in the face of the carbon , (please zoom in on pic)
I am infusing on a sheet of glass as a test.
I have 30 IN Hg vac , no leaks, holds vac for duration of cure.
using 4 layers of carbon , peel ply , flow mesh then vac plastic sheet.
I am clamping the resin line just as the resin gets to the vac line , then clamping off vac line about a min later.
Also tried not clamping vac line and leaving the pump on . ( worse)
I am mixing EP 085 resin 100 g to HP 085 hardener 35g mixing for 1 min then de-gassing for 10 mins in the catch pot prior to infusing.
Is your catch pot a home made ??
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Old 11-08-2017, 07:14 PM   #19
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Quote:
Originally Posted by Floflo68 View Post
Hi,is it the same thing if you don't use MTI?
Yes this is a general rule to use for infusing with or without MTI hose. However keep in mind its only general and you may need to make further adjustments. And if you use spiral, typical setup is to use peel ply to connect vacuum source to laminate, spaced 50-100mm. Though again there are variants to this rule.
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Old 11-08-2017, 09:47 PM   #20
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Some great info here.
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