its a molecular debate

if the pores are small enough to stop the relatively long epoxy molecules from passing through, yet small enough to let the various air molecules through then it might work, however from what i understand, the bigger epoxy molecules will just block up the pores making it impossible for air to get through.

Sure vacuum will pull on any bit of hose where its not wet, but as soon as it is wet, how can a vacuum pull any more? you would have to rely on the bag naturally evening out the vacuum all over (which it will do) once the resin feed is clamped.

but the excess resin around the resin feed isnt going to distribute itself as theres no force pulling it. hence resin rich towards the resin feed of the part and a uneven laminate.

probably fine for more cosmetic and non-critical structural parts though.

I guess with practice you could calculate your theoretical resin uptake for the layup and then clamp the resin feed a little early as some do with normal infusion allowing the excess to flow to the edges. However that only works on normal infusion because in reality you have an excess of resin that will go into the vacuum line/catch pot so in practice you dont have to be too precise, just make sure you havent got too little resin.

Hi, I´m new to this forum but I can tell you something about my experiences with the MTI-hose. I`ve been working on motorcycle parts since 2003 just for private use. These parts are e.g. an airbox seat monocoque, gas tank, fenders etc. and consists of carbon fibre. During that evolution period of nearly 10 years I digged deep into the process of how to produce perfect carbon fibre parts. Starting with open moulds and a wet layup turning to the closed mould process and resin infusion I was never able to produce absolute pinhole free parts. So rework was necessary all the time. Especially the sharp edge design of the new parts I`ve been working on since the beginning of this year forced me to reassess the manufacturing process. I came across the MTI-hose and gave it a try. With amazing success. Since I learned how to make a 100% tight vacuum bag I`m able to produce perfect cosmetic parts. I`m happy with that product since the produced parts are now 100% pinhole free and no rework is necessary. I also use a clear PU inmould coating wich is UV resistant.


Regards

Have you actually tried this product or is this just theory?
I've received a sample a few month ago and have ordered more since.
Never had any problems with pinholes or resin rich areas. It's a truly remarkable product, such a shame easycomposites.com don't sell it (the guy I spoke to actually said that he tried to contact these guys but never got any answers)

Hi Sebgron, 

I don't agree. If you look at that membrane and compare it to the behaviour of a paint filter for example. You can pour water through it easily. (think of the water as the Vacuum) Now pour in a hand full of wet sand.(representing the resin ) You can still pour water through the filter no problem as it will flow through and around the sand) just as the air will.

Fred 

Here are some interesting videos about MTI, its benefits and proper use:http://www.youtube.com/user/GAComposites

Hello,

the MTI hose is our product. I like the discussion here, that shows me people think about things and do not just believe in what is told them.
The thing with the oversaturation can be correct if you let your resin feed line open.
But you will get really fast a feeling for that. You can also place your resin feed about 1-1.5 meter below your part. This height difference will create a presure difference that will prevent a oversaturation. We have a study here wherethey produced pinhole and void free part by MTI hose with a VF between 62 and 67%
The reason why we did not make a hose with slightly bigger poores is that than the physical advantage of the hose will be gone.
Now you have a closed system after infusion where no vacuum is working, but the full ambient pressure will compact the laminate. If the poores will be a little bigger, the vacuum can still pull resin out and so air inside the part can cause micro voids, pinholes or other mistakes.
I added the video of how it works, I hope it helps to understand the advantages.



Dominik

This product will save you time and money,may be easy composite can be a distributer.  

That depends.....

For an experienced laminator, alot of the issues the MTI claims to solve, will very rarely be a problem....

for the less experienced or DIY'er, I can see why it might appeal.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant