I am happy to hear that you also got very good results every time. But why is it too expensive? If you get good results and you have less afterwork it will not be expensive. On a fender for a motorcycle you maybe spend 1.5m, if you save 1 hour of grinding and 1 additional layer of clearcoating you will save a lot of money.
But I often hear the argument that peolpe grind and clearcoat semthelf and that the money for the clearcoat and the sandpaper is a few cent less than the MTI hose. But if you want to earn money with the parts time is money, and than the MTI hose is much cheaper in the end.
We have a lot customer in the UK but still no distributor. They all seem to think that the MTI hose is not interesting. I am also sorry that shipping costs to the UK are so expensive, we are working on a solution.
To some people in the UK I offered to ship direct, than we can give you a shipping rate of 5€ for shipping up to 10m. Of course everybody in the UK can order direct until we have a distributor in the UK.
Hi
It is a great product but 10m cost me £62 and 10m of spiral is only £3.50 and i use an in mould clear gel coat so i have little finishing work to do.
Regards Chris
www.carbonfibreworks.co.uk
Right now I am waiting for my sample to do some tests, but there is something I need to ask, If the hose gets blocked once the resin touchs it, how can any bubbles left behind by the resin front get evacuated ?? it seems that with a spiral tube even at the expense of letting some resin end inside the resin trap bubbles could be evacuated, something that does not seem feasible with the MTI hose …
That is where the high vacuum jumps in: The voids that might be left behind, are near-perfect vacuum (if you managed to get a good vacuum). Once the resin hits the MTI hose, the vacuum in the resin drops. This makes the occasional void collapse. Really smart material.
You are right, you can not evacuate any air bubbles in the resin. But you can not do that with a spiral. With a spiral the vacuum is stil working so that the air bubbles expand a ,ot and may be reach the spiral so that they can than be evacuated. BUT also the air in the laminate increases.
With MTI the vacuum will not be there once your resin hits the membrane everywhere. You can see that the airbubbles in the flow front will collaps immediately once the part is filled. And that is the part where your laminate quality will increase and not the voids.
Edit: Herman was faster
Thanks Herman and Dominike, But then when the resin hits the hose everywhere, the pressure diferential would have totally dissapeared and then with it all the desired compaction, IMHO, if a structural piece is desired (as in my case, as Herman knows boat Hulls) then either a double compaction with a double bag or sucking from the bottom resin lines to a trap would become almost a neccessity to avoid a too resin rich piece, particularly in my case where the sides of the boat hull would be 1.8 m high and the gravity should tend to produce “a lake” of resin at the bottom. Only theorizing … an likely wrong but this is how I see it.
Another thing that worries me (no Hose related) would be the decision of at which distance of the moulds top edge, should the resin inlets be clamped off to avoid the aforementioned resin pooling.
I ordered 20 of your miniclamps today togehter with some sample hose, hope they are nice, they certainly do look nice.
Dominike may I ask your permit to insert some pics of our mould in your thread for a better understanding of my worries :)??
Herman, isnt this the same case when the resin hits the vacuum source in all infusions ? I don’t use spiral tube wrapped with peel ply…I use just one layer of peel-ply to slow the resin feed as a field/path to my vac signal tube which is offset to the edge of my mold.
I’m using Compoflex - (combo peelply and mesh). But for the vac signal just basic peelply fabric.
Is the MTI hose predominatly for stopping resin leaching after full infusion ?
Yeah the pressure difference and double bag discussion…
You only need the pressure difference to get the resin in. Also your fibre to volume content (VF)can be influenced by the pressure difference in the end.
Double bag will not help you with resin pooling or VF, just take a look at the double bag thread
http://www.compositescentral.com/showthread.php?t=7075&highlight=double+bag
At a mould with a height difference you will always have a different VF depending at the height because of the gravity. That can be minimized by adjusting the conter pressure in the resin feed.
But even at boats, wind energy blades or other big parts this is not that big problem because you can still get a VF>50%
Your mould ist not that problem, the difference of about 1.8m is not that problem. That is a pressure difference of about 180mbar.
Here the picture of the mould.
If you work with MTI I would place the resin pot deeper on the ground and wait until the resin stops traveling in the mould. so you can be sure that every fabric is saturated and your VF will be good because of the pressure difference you create by placing the resin pot deeper than the lowest point of the mould.
And I am sure you like the clamps, If not you can send them back.
@worldwealth: The MTI hose is not mainly for stopping resin leaching. It creates a closed system in the end of the infusion and allows to create a pressure balanced system. And that makes it possible to get a equal laminate with minimum voids and at least no pinholes.
Mr Worldwealth sorry to ask, but what do you mean with “vac signal” or “vac signal tube” english-american has so many abreviatures and short words that has become almost another language.
Just the vacuum line (spiral) under the bag.
Herman nailed it. I just don’t use spiral tube any longer. I replaced it with any breathable thin material like peelply. As soon as the resin flow front hits it, the resin slows to a near zero travel. My vacuum tube/line just reaches into the bag a few inches and restd atop the peelply strip.
Does the MTI hose do the same thing but just keep the vacuum level higher due to the nonpervious resin flow stopping ?
I guess I’m confused at this > Once resin stops at the MTI membrane or my Peelply the vacuum level is now deadheaded right at the resin with both materials.
Right or wrong?
Found something in the web that suits to this discussion. Abaris “Road Tested” the MTI hose for Infusion.
Ive experienced that the resin blocking effect is not the only thing the MTI hose is good for. Far more important is that you are able to create an absolute closed hydraulic system which makes it easy to control and adjust the vacuum level to a point that let possibly entrapped air bubbles collapse (Herman mentioned that already). This affects the porosity of the laminate. We did a test series with microsections showing that the porosity of a 30mm thick laminate is by 13% better with MTI than with peel ply brake zone processes. You can even hear that. A laminate produced by MTI sounds like ceramic when you knock on it. We also experienced that, especially with a very thin resin, unlike MTI a peel ply brake zone doesnt really stop the resin from being drawn out of the laminate. Particularly with a very long pot-life this eventually leads to a bleeding-out of the laminate. And this in turn results in pinholes on the surface affecting the post treatment effort with cosmetic carbon fiber parts. And even by the application of a clear InMould coating you can`t avoid that the pinholes appear as tiny voids under the coating. Another point, particularly interesting for serial productions such as wind turbine blades, is that the MTI hose helps reducing cycle time.
All good points. I had read that Abaris report when it came out. I am wondering if the MTI hose only really works its best as a full perimeter placement ? Currently I cross infuse ( one side fed, one side vacuum) and only require about a 12" peel ply field to infuse a 5’x4’ in 40 minutes with the resin B-staging at 50 min…So bleed-out of resin isn’t my concern at all.
I use resin feed line fully down the opposite end with it wrapping around each corner and up about 1/3 of the way on each side. Much like this >> [ ’
What I believe to be surface tension when I dont use IMC creates some very minute’ voids against the mold and carbon.
However, when I use an IMC, this does not occur, even under inspection with a maglamp.
Perhaps the MTI hose does create a higher constant draw for entrapped air thus overpowering the surface tension and trapped air.
I had enquired to DDCompound for a trial sample and he encouraged me to contact his Florida distributor, I did so but never heard back from them. I’m in the midst of building re-useable bagging framed sytems and I have to be done with componet testing quickly because I’ll be locked in with whatever channels/consumables my silicone bags are built around for production.
AT this point, I’m not even sure exactly what it even cost per yard? I’d seen elsewhere on another forum they mentioned 27 sterling lbs or nearly $44.00 US. Does anyone know ?
I think German Advanced Composites, the US distributor has answered but sometimes those emails get classified as spam. You can place an order there via online shop. GAC`s warehouse and distribution center is located in Florida so an order should reach any location in the USA within a week.
Are you affiliated with their Florida branch ?
Its my company! By the way, the MTI hose would also work well with your infusion setup (one side feed line, one side vac line). Theres no need to place it around the entire perimeter.
I looked in my junk mail, just in case I missed an email…but nothing there from you. Did you receive it? I’m trying to nail down the consumables that fit inside re-useable silicon vacuum bags. As you know, once they are made your stuck with the internal channel dims.
-Vince
Hi Vince,
Yes I received it and answered the same day, Dec. 6th. Please check also your CCF account. I`ve sent a private message today.
Juergen
Just got my 30’ in the mail…I will be giving my newly arrived MTI hose a try in the next few days…hopefully it all works like it should. If it doesn’t, I’m 100% sure it’ll be something I did, not my consumables…