Ive been using shd a lot more at work. But the vtc401 in the clave and the press. Hopefully trying out df212 this week on some sports equipment.

Hanaldo, I think it is most want to have a material where the guidelines given work 100%, 100% of the time regardless of what oven they have or how they run the schedule. It does take some work and needs to be done correctly with a controller. Do that and work on the timings and ramp rates a little and it does work perfectly as you and I know.  If I could just say do A, B, C and D then it works that would be great. But you cannot allow for people doing it manually or the small lay up issues people 100% right with your lay up and bagging and then it is all down to the oven and the controller. I think a ramp and dwell controller is as important as any other part of the process.  

Same with EasyPreg. I had some issues making these parts initially, but after working on my cure schedule (with some help from morepower!) and layup technique I can bang them out 100% pinhole free now. Top picture is straight out of the mould with just the outside edges trimmed, bottom picture is trimmed and clear coated (just for the sake of it, a lot of people think clear coating shows up pinholes that otherwise can't be seen. Nothing of the sort here!). It's definitely possible to get genuine free results with good quality OOA pre-preg.

It may not be the most complex shape but it does have compound curves and several changes of direction and tight corners to lay into. This was the first out of the new mould so I expected one or two issues but pinholes is not one of them. The SHD material really is an amazing OOA product..

We have tested a few OOA carbon fiber prepregs some time ago, and generally OOA prepregs works with simple geometry.
Complicated geometry results in pinholes (often small - but to sell products to client you need to works with pinholes - time consuming painting)

Since we bought autoclave we have 0 pinholes problem. 

Carbon fiber sheets and composites .
www.dexcraft.com

SHD have a new material they are developing. Its a higher temperature cure but still classed as a low temp resin system with an 85 degree C cure being needed. The spec sheet recommended cure will be all you need to use (Currently it is 65 degrees for 2 hours with a 1 degree per minute ramp then 16 hours at 85 degrees C with the same ramp rate to get up to temp) and it works perfectly.  I have made two parts this week. One had some pinholes  (60 degree C, dwell 60 minutes, 70 degree C also 60 minute dwell then 85 degrees for 16 hours). The second was perfect with the cure I first mentioned (65 degrees for 2 hours then 85 for the rest of the cure). Speed of ramp is important but I think the dwell and staged cure is the key. If I know the gel time then I could ramp up after that to speed the cure up but then the energy needed to run those higher temps means all I am saving is time not energy. 


The above part has pinholes. Not big ones but I can see them. The clarity of the new resin makes it a pain to get photos of indoors so its like taking photos of a black mirror.

Below the part is flawless and it was a simple cure cycle change. Its hard to believe a small difference can make such a change but it shows how the use of a good controller can possibly improve your parts. 



To avoid cheating and posting images of prepped or finished parts all my photos are out of the mould and untrimmed. This is exactly how they come out of the mould good or bad. 

Thanks for the comprehensive reply morepower, it certainly seems like it's worth trying out with so many potential advantages

Mark

Mark. To be honest ignore the fact you CAN get a 3 hour cure. Too many seem to want to cure hot and fast. It does not allow the resin to flow and get the surface you want. 

They have other backing materials they can suggest to go with the DF212... But there will be another new material which will have various weights, better clarity but will need to be cured at a slightly higher temperature. But I will say even the DF 212 has better clarity than the VTF261 (Easy Preg surface). It would take minimal experimenting  to be honest as the cure cycle on the PDF is very close as I gave them that info. It is more about having an accurate and consistent oven. The breather stack is where you may need to do some fine tuning but that varies from mould to mould.  

Price? I know what price I pay but I will say it is quite a big saving over EC's material. 

Pro's. 
Better clarity

Having had a look at the SHD PDF, it certainly does look like it offers the opportunity for some short cure cycles, down to 3 hours for temperatures within the range of the Unimould tooling system

morepower - Is DF212 just the surface layer fabric and does it need to be backed up with another of their products, or does it come in various weights? Also, how does it stack up in terms of price when compared with EC's OOA fabric?

Realistically, will it also take fair bit of experimentation in order to achieve perfect surface finish results using this, assuming that the user has an oven with stable temperature control and the ability to ramp appropriately

Certainly looks appealing, but would just like to fully understand any 'cons' to trying it, as opposed to EC's material and I'm sure that you're well placed to make a realistic assessment of that

Cheers

Mark