MTI hose

I used 824, the flow media did stop short of the laminate, I’m using 3k 2x2 carbon followed by a layer of glass with another of carbon, I clamp both the pump line and resin line once the laminate is fully saturated, I degas my resin with heat so the exotherm usually trashes the resin pot within 20 min. The Mti hose is never fully saturated with resin so that’s why I clamp my pump line because it isn’t sealed. I just made another part which came out well with no voids or bubbles but still had the dry compact look. What can I do to get a more wet optic look? I go back to work in a week so I may be able to make 1-2 more before then

Also I have been using the envelope method to make sure my bag is air tight and when I infuse the resin travels to the backside of the mold which is annoying and I think a waste of resin. Any suggestions?

You shouldnt clamp off the pump side once youre done with infusion. Are you using green mesh 75? I would recommend trying the red flow mesh instead. The laminate will have higher resin content, but surface will look better

Any thoughts on whether infusion (with or without MTI hose) would be possible to use to infuse resin into the fiber reinforcement of a bonded tube join?

Pictures to hopefully help illustrate:

Hello,

that should be possible. Make the same layup with fabrics, peelply, perf and flow media and than bag it.
But make sure the frame is tight, not tha you will fill the frame with resin or pull air through the frame into your laminate.
But this is a classic situation for a perfect wet layup or prepreg.

Hi DDCompound, what precautions should i take in order to ensure a resin rich part when using MTI hose or the fact that no resin is allowed to exit guarantees a resin rich part?

To prevent resin pooling and a resin rich part place the resin pot about 3-4ft below the part. So the gravity prevents that to much resin is sucked in the part.

Hmmm, i thought if too much resin is sucked into the laminate i will end up with a resin rich part :(. lastly i just watched the following video https://www.youtube.com/watch?v=V7_h34vJ3oQ and i noticed that you added perforated release film, any idea why? i never use it when infusing my parts, could this also contribute to the reason why i don’t get resin rich parts?

Using perforated release film makes it easier to remove the infusion mesh after it is infused. Peel ply goes very stiff, so can be quite difficult to remove.

If you want a resin rich part, you simply let more resin in before clamping it off? Even once the MTI hose has been blocked by the resin, more resin will continue to flow into the part. If you want it to be resin rich, just leave the resin feed line unclamped for 15-30 seconds after the part is fully infused, then clamp it off.

Oh, I thought you don’t want a resin rich part. If you want a visiual
part that should be resin rich to prevent the flattened look just place the Resin potat the same hight than the part and let it open until no resin is sucked in.
There a two reasons why I use perf release. First like hanaldo said it is easier to remove the flow media, and second it helps to degas at the flow front while infusion.

so if i need the flat look i need to place the resin pot lower than the part

Yes, than deeper it is placed than higher the VF and that makes the fabric look flattened like most prepreg parts.

Due to my production cycling, I’d like to be able to remove vacuum draw from my bagged components relatively quickly. To try and accommodate this, I’ve started with a new approach: I lay my MTI hose on a slip of peel ply that is taped to the mold, and then once my bag is drawn down my brake area of my laminate’s peel ply ends up falling on top of my MTI hose. In effect, the hose is fully enveloped within a peel ply sheath. So once my resin front hits it, the hose’s membrane should wet out and seal fairly rapidly, correct?? Meaning that in effect, the bag becomes sealed from the vaccum draw, and I’ll be able to clamp and remove it fairly quickly?

Also, once the hose becomes fully sealed, what’s a good amount of time to wait before clamping off the resin feed line? I know the ideal method is to not clamp it at all, but again, because of production cycling I’d like to be able to do so. Essentially once the hose is fully sealed off the correct pressure of resin is drawn in, correct? I keep my feed pot about .5 meters down from my mold.
Thanks

How thick are you parts? If they are not thicker than lets say 5mm you can clamp off all lines when the resin hits the MTI hose everywhere. If your system is tight that is no problem.

Yes, they are much thinner than that, so that’s good to hear.

I’ve been noticing a surprising number of hose failures (maybe 1 in every 5) recently. I’ve pinned it down to having too much membrane hose at the far end of the set up, without any spiral tube support within. If there is more than 1cm of unsupported membrane then the likelihood of a failure (full flooding of the evacuation line) increases significantly. I go overkill for sealing so I doubt that that’s a problem

I posted here in the thread somewhere how to seal the ends. You can find these information also on the german advanced composites homepage.
In nearly all cases it has been a handling failure if resin got in the MTI hose.

is there a website (US) where i can buy it , i would like to try this product

Take a look at our homepage www.dd-compound.com
You will find there a list of distributors.

Please follow this linkto MTI hose - Episode 5 - Prepairing the membrane hose, to learn the simpliest and most reliable sealing method. If you are accurate with this it`ll never fail.

In the USA you can place an order through German Advanced Composites`online shop. They have a warehouse and distribution center in Florida.