When resin reaches the MTI hose the resin inlet will be stopped, but than there is a lot of resin in the part, you will have a VF of about 35%. If you place the resin pot 1m below your part your VF will be about 50%.
You should just infuse so much resin until your part is wetted out, thats a bit experience. If you want to make cosmetic parts you can choose the lower vf for a better optic. Fabrics are not so much compacted so you will get a more “living” laminate.
A further pro is that if you let the resin infuse until it stopps by itself there is no pressure difference between the part and the ambient pressure, so no air wants to travel in your part.
For technical parts you can clamp the resin inlet before the resin reaches the MTI hose, than you can get vf’s of about 60% up to 65%.
Thanks, that is making sense, so in an ideal world I would clamp the inlet hose at say 95% leave vacuum on and the resin already in the mould would then wet out the last 5%, it would wet out 100% but no more, not reach MTI hose and with the vac still on it would simply be removing any trapped air, [FONT=Tahoma]correct.[/FONT]
The resin should reach the MTI hose, but you can clamp the feed line before it reaches the MTI hose. There is always more resin at the inlet point, depending on your feed line diameter and where you placed your resin pot more or less.
You should clamp your feed line so that the amount of resin is too much at the inlet can travel to the non saturated fabrics. Than you will get a perfect homogene part.
If the resin does not reach the MTI hose there is the danger of creating dry spots. The main function of the MTI hose is to stop the resin that you can create a closed system where no gases can expand. This minimizes voids.
That requires a bit of trial. Another option is to apply vacuum on the resin inlet after infusion. (can be done by adding a T-piece and a valve in the inlet, and rig that to the catch pot).
In normal infusion, this creates no problems. Will the MTI hose create a challenge? After all, there is no “spare” resin in the MTI hose to add to the laminate. However, I think there will be no problem. After applying a vacuum to the inlet side, excess resin starts to travel to the catch pot, causing a slight drop in vacuum compared to the MTI side. I do not think a situation is reached where resin wants to travel away from the MTI hose. Perhaps only when gravity is a factor as well.
Something to think about…
Hello to everyone… Rich from sunny San Diego California here. This is my first post here at CC.
I have an MTI question but please bear with me… I am preparing to a build 16-foot standup paddle catamaran (standamaran). The molds for each pontoon will be two-piece with the hull mold 5 meters long x 8 inches wide and 5 inches deep. The deck mold is 5 meters long x 8 inches wide and 3 inches deep.
If I have to wrap MTI around four molds (hull and deck) x 2 pontoons that’s 40 meters of MTI to build a boat… its going to get pricey. Is there a cost effective method? Is it ok to run the spiral resin inflow tube up one side of the mold and the MTI up the other side so it’s drawn across the mold instead of feeding from the center thus eliminating the need to wrap MTI around the entire mold?
Any tips would be appreciated. Thanks!
Yes, that should be no problem.
Just make sure your split moulds are airtight, or envelop-bag them.
Hello,
infusing across will be no problem at your part size. It will be slower, but you can take a resin with a long pot time. I would take a epoxy resin.
Maybe you can post some pictures of the mould so we can help you.
Hello everybody,
my name is Jürgen from western Germany. Im new here to this forum and Id like to share my experiences with the MTI-hose. Since 2003 Ive been spending most of my spare time with the evolution process of my custom motorcycle. One of my ongoing targets is to reduce the weight to the lowest possible point. For that I dug, besides other issues, into the production process of carbon fibre parts. As engineer I always try to raise the bar to achieve the highest possible outcome. But all the parts I´ve produced in the period 2004 until November 2011 were full of defects which required lots of rework. Above all I had problems with pinholes which are not very useful when the parts have to be painted with clear lacquer. Also air bubbles in all kind of sizes often brought me to finish the parts with an additional layer of carbon tissue on top with all the necessary rework. To avoid that, Ive tried various methods, with more or less success. Very frustrating…;-)) Due to the special design of the new parts Ive been working on since December 2010 I decided to delve into the infusion process. I came across the MTI-hose and and carried out experiments with this auxiliary material. At the end I´m very happy with this decision since it didnt take long to achieve the best results Ive ever reached. In spite of the sharp edge design of the parts, no airbubbles, no pinholes which means no rework. What Ive learned during this exercise is, that the outcome gets better, the lower the vaccum is(my pump achieves less than 20 mbar). And a tight vaccum bag is also necessary. Unfortunately I was forced to interrupt the production process for a job-related stay in Brasil for 8 weeks. But I`m confident to finish the parts until July 2012…;-))
Anybody selling this hose in US yet?
Thanks, Ro
I attempted to order online but the web cite wouldn’t allow me to put in United States under country.
In hopes of us in the US getting our hands on some of this. Perhaps a supplier could put together a list to ship everything to a central location here in the states and one of us could re-distribute them to the rest of those who have ordered?
If so, I’ll add my name to the list.
- 2talljohn
I have been ordering mine directly from DDCompound. I would be interested in a large group order as John suggested. Maybe we could get a group rate and save some money?
Rotorage wanted to do that, but he started a new job. So he was not able to do that. We are still looking for a distributor. They don’t believe that there are advanteges by using our product:( So I think I have to make a journey to show them that it is a great product. We had the same problems here in Germany and now the distributors contact us because they want to sell the product.
At the moment it seems that we will send a person from Germany to the US who will be the general importeur to resell the MTI hose. Thats the latest point when you can buy the MTI hose in the US.
At the moment you can order direct at me, we can send 10m pieces as letter so it is not too expensive, and bigger quantities by UPS.
I was talking to a shop about MTI hose and they think it is just spiral tubing wrapped in peel ply. They didnt realize it doesn’t allow resin to flow through it. I explained how well it worked.
DD, will contact you off site. Might have some outlet point for you in the USA.
Yes, it is a big problem that people do not understand the function of the MTI hose. But if they understand it they like it.
Thanks Herman, I will contact you.
And thank you all for talking to your distributors. You need one who starts with the product and who is motivated to sell it.
I"ll talk to an opperations manager at a place called Fiberglass Coatings Inc in South Florida. He’s very interested in catoring to the infusion market so I’ll see what he thinks.
Group buy list.
- 2tlalJohn
- dpaine
Sie werden es mögen? Nein, sie werden es lieben! Alle Tests auf Prepreg mit dem MTI wie Dallas früh in diesem Thread erwähnt worden war getan haben?
Yes, they will love it. Like all the other people who tested it. We have costumer who use the MTI hose in combination with prepregs and they also have a lot of advantages.
I don’t know if anybody here has made tests with prepregs and the MTI hose.
What kind of advantages are supposed to be found using the MTI hose with prepregs?