MTI hose

General Composites Discussions Products Talk
#381

Been using this hose for about a year now.

Love how easy it is and I wouldn’t be doing infusions without it.

#382

I agree with sduffas above. I’ve been using this hose for a year or two. I see people talk about the price. If I’m working with an expensive material such as carbon fiber and epoxy why would I scimp on ancillaries. It saves me a lot of time and money and makes a perfect part as Juergen and Dominic say. I just pulled a BMW hood today and it came out without a single defect or dry spot. There’s other things that need to be done to insure such a part but you gotta stick with it and use top quality materials.

#383

Having my first issue really that I can’t figure out and I’m not sure if it’s related to the hose or not.

I’m getting dry spots in my infusion but have no bag leaks, it’s strange because the only time I’ve ever had dry spots is when I’ve sucked in air or when the epoxy’s geled to early so there wasn’t enough in the part.

Well I pulled a part up the other night and it had air voids. These voids were both on the front and back of the part. Sometimes I’ve seen slight pockets on the back but they never effected the front of the part, rarely though.

I just did another part, and paid close attention to maybe any bridging I had with relief cuts in areas that will be cut out later, and also made sure everything was 100%. I infused like normal degassing the epoxy and infused.

Things I noticed that I never thought may be a concern or not

  1. When you suck in epoxy at first you get an air void in the the hose when you unclamp it. This usually transfers into air in the part and you can see little bubbles of air going through the media flow.

  2. There’s no bridging in my part, I’ve done this part like 10 times and never had an issue before the other day

  3. There’s little micro bubbles on the same end of the part on the backside that I see, extremely small.

  4. I know it’s not my resin not degassing because I do 2x parts with the same pot.

  5. I do the part that’s giving me problems first, then the 2nd part last.

  6. The parts are hooked up to the same vacuum source and it’s T’d off but don’t think that has any effect on it.

  7. The resin pot is below half the part “since the part’s angled”, and the other half it’s not. The part where I’m getting air is above the resin pot.

Am I shutting off my resin inlet to early? I have media flow only in the part and about a 1 inch gap before the mti hose. I usually clamp the epoxy inlet shut when it’s infused the media flow but not to the mti hose since I figured there’s enough epoxy in the part.

Any tips would be appreciated.

#384

Hello, I can not direct see a failure. Please post pictures of the part and the mistake. Dryspots only appear when air gets into the system, so we have to look where it comes from. And when you have tiny micro bubbles there is air. Sometimes things are different from part to part.
We will fix your problem :slight_smile:

#385

Could it be I’m clamping the resin inlet off to soon?

#386

That will not end in classic dry spots. If you clamp to early you may get pinholes or underimpregnated fabrics but ni really dry fabrics. To tell you what it is I need to see the failure and the part so that I can see where it happened.

#387

That makes sense. I interchanged the terms. I had pin holes rather in between weaves. I did another part and shut off the inlet when all the resin hit the hose and also extended my media flow slightly closer to the hose itself and put the hose hose slightly more away from the part so if air was being sucked in it would give the bubbles more time to get out.

#388

Called, didnt get an answer so I figured I’d take a detour on the way to the shop and buy some in person. Wasted half my morning driving through the ass end of downtown Miami to find out that their on vacation… Or not? They couldn’t tell me for sure so I didn’t know if the guy went to an early lunch chance and I can wait or if he’s in Bora Bora for 2 weeks… At least parking wasn’t too expensive… F*** it…

#389

Hey there, Im Juergen Schildgen the CEO of German Advanced Composites. Sorry that we couldnt meet in person today. My secretary called me when you were in the office but unfortunately I couldnt answer since I had another phone call at this time. Im traveling a lot to clients and sometimes its easier to reach me by email. If you tried that first Id have had the chance to inform you about a few things.

1: German Advanced Composites is the general importer of the MTI hose. Our office is located in Downtown Miami but we do not sell any products there.
2: Our warehouse and distribution center is located in Vero Beach, Florida but also there we do not have a shop counter were you can buy the product.
3: We are working on a nationwide distribution network which means that we`re seeking partnerships with composite suppliers. We made some progress but until today the only way to buy the product in the USA and Canada is by placing an order via online shop. Any incoming order is processed the same day if it comes in before noon, otherwise the day after. Also we reach any location within the the USA and Canada within 2 to 7 days. Hope these information helps you to get your hands on the material and give it a try.

#390

J just got off the phone with Juergen and I must say I couldn’t be happier to have spoken to him. he answer all my questions, and 4 me about the best places to order. I will surely be placing an order and I look forward to getting in late this week. Once I get it and make a few parts I will post my personal results.

#391

Found and confirmed my issue. I was cutting off the resin inlet to early. Now I just let the epoxy hit the hose then clamp.

#392

Hi guys for those of you who are well experienced with MTI hose i want to know if there’s need to surround the laminate with the hose, i was thinking i can apply the hose on one side of the mold (half of it on the vaccum outlet side) then on the inlet use the normal spiral or no spiral @ all. i was thinking this could save me some material and at the same time reap the benefits of using MTI hose. any comments/suggestions will be greatly appreciated.

thanks

#393

If you have a simple part where you can infuse across you can put MTI on the one side and normal spiral as resin feed on the other side. That is no problem.
On more complex or bigger parts we reccomend to place it around the perimetre for a higher process stability, even if you don’t know how the resin will travel.

#394

An article in the composite world about semipermeable membranes. It is also about other membrane systems and gives a nice overwiev.
http://www.compositesworld.com/articles/semipermeables-next-trend-in-infusion

#395

Great article in Composite Technology I read yesterday. It’s called “Next Trend In Infusion”. Talks about MTI infusion hose. I felt ahead having met Juergan and Dominic and using their products because of this site. Thanks to all you guys.

#396

Couldn’t agree more! Both are very knowledgeable and friendly.

The magazine was just delivered to work the other day.

#397

Hello to all, I have a few questions about infusion with the MTI hose. First some background on me, I do this simply as a side hobby not really making much money on it so I would like to avoid spending a fortune on tools and materials. I have done a few wet lay ups and a few vacc bags with limited success. I always have multiple voids, pinholes, etc. I would like to finally produce a good piece with a quality finish and am hoping to do so using infusion and the MTI hose. I have recently purchased some MTI hose (15 ft). Also a RobinAir pump 15600 which is supposed to be capable of 29hg (2 stage 6cfm) Viot vacuum switch controller to replace my current set up of a fridge compressor and a car vacuum switch rigged with springs. I also have a pvc pipe catch can and vac gauge. I hope this isn’t off topic but I know a lot here have had good luck with the MTI hose and have a lot of experience so basically my questions are:

  1. Where can I find good consumables and tools cheap? Flow mesh (what kind should I use), infusion resin, connectors/ports, mold release (what kind should I use and why? There seems to be a million opinions!), vac line cut off/valve, vac gauge, tacky tape, bagging materials, catch can, etc. Preferably in the U.S. and at decent prices, I can’t really afford to pay $300 for a digital vac gauge or $200 for a catch can as this is just a side hobby.

  2. What’s the actual process of infusion? I get the concept but not sure of the steps taken.

  3. What resin to use? I usually buy my resin from Ebay, its called Max CLR, they also sell a infusion resin http://www.ebay.com/itm/VACUUM-INFUSION-EPOXY-RESIN-VERY-THIN-CRYSTAL-CLEAR-FAST-INFUSION-HEAT-RESISTANT-/221037444081?pt=LH_DefaultDomain_0&hash=item3376dbbbf1  Is this any good? Most of my parts are automotive and will be outside in the sun so they need to react well to heat and sunlight.

  4. When using pva I notice that the surface is never perfect. How can I get a perfect surface on my parts but still have my parts release from the mold?

  5. How should I set up my infusion vacuum system? Are there any more things I need to buy?

  6. Resin flow, how to an effect it to make a cosmetic part or a more “dry” part. I’ve read in the thread that changing the viscosity of the resin or lowering the resin pot effects this but how and in which way? What should I do for a cosmetic part, or vice versa? And also does VF stand for volume fiber content? Can anyone break this down for me “barney style” like me say in the military!

Any help would be appreciated. I’ve read through this thread at least twice and some of the stuff seems like another language to me! Any I apologize if my response has been misplaced. Ive attached some pics of my old project and set up.

#398
  1. Also forgot to ask about the spray adhesive, sometimes i see it is used or mentioned, does it have to be used? also how do you avoid it showing on your finished part? Also what kind to use.
#399

The attached PDF document may answer question 2 for you. It talkes about the basics of vacuum infusion, the driving force, how to measure it, extraction performance, vacuum integrity and the significance of leaks, vapour pressure, degassing, the self-regulating MTI process and handling of the MTI hose. Also, the MTI Instruction Manual gives you some hints in regards to a proper setup and the simplicity of the system.

[ame=“http://www.youtube.com/watch?v=V7_h34vJ3oQ&list=PLnpGU4-6KuyY1hfx0hBSUftLDdPoxUabh”]MTI hose - Instruction Manual[/ame]

#400

Thanks, im definitely going to look over the pdf.