The Easy-lease chemical release agent works well, as advertised, but be aware if using wax (as per the tutorial video) the wax must go on afterwards. I made the mistake of thinking if they could be used together it didn't matter the order, but applying the wax first interferes with the Easy-lease and the whole thing breaks down. Cue one ruined mould where the resin adhered. Second time around I used the easy-lease on it's on and it was absolutely fine, so I would recommend this.

The knitted flow mesh really is an excellent product and for a complicated part is highly recommended. It has all lot more give and stretch the the standard mesh so really gets into tight corners and odd radius bends where the usual mesh may bridge - only thing to be aware is that it is thicker and fills with the resin so is harder to remove - it does get quite stiff. You also need to apply release film (bread wrap) between it and the peel ply which is a bit of a faff.

Cutting and overlapping peel ply for a complicated part is worth considering to help avoid bridging although you do get an edge at the overlap in the final part. I also found that at the edge fibres from the peel ply tended to get stuck in the part.

I found the 210gsm mat quite difficult to work with compared to the heavier weights for a more overly contoured part, particularly in a narrow channel section - it didn't have as much give, or drape as well, and as it is one layer of weave could open up if not careful. I initially chose it to help avoid bridging, but it made it much harder. It would lift in one area as another was pushed down (using the fusionfix) and generally didn't conform. I went through several rounds of having to open the vacuum bag and peel the whole stack up after I found the 210 mat had bridged in tight corners. For the final part I went with the 450 as the top layer and was much easier. Others may not have this issue, however, and I can see for a relatively straightforward part the 210 would be fine.

If the part is small enough consider envelope bagging the whole part rather than just applying the bagging film on one side. 2 reasons - a) it is potentially a bit simpler as it doesn't require pleats and you only have tape at the ends to leak and b) If the mould is a bit ropey (as my first one was) you can get leaks through the mould which are almost impossible to find and fix. I spent weeks searching in vain for tiny leaks, and in the end just bagged the whole thing. The rough surface on the back of the mould could pierce the vacuum bag so I laid down two layers of peel ply on the back and spent some time taping over the pointier areas. Downsides as far as I can see is that resin escapes around the back of the mould, and the vacuum bag can get caught up around the back of the mould, overstretching and tearing.

It is perfectly fine to leave the pump running whilst the epoxy hardens. There seemed to be slightly conflicting info on whether you should or not, and I was a bit confused. Having spoken to EC tech support, their line is that if you have a perfect vacuum (or as near to as makes no difference), i.e. you see no change on the vacuum drop test and the vacuum is going to be maintained for the duration then you just don't need to leave the pump running and can clamp off. However, you can still leave the pump running if you'd prefer, or if there are some minor leaks that you cannot find - as long as your vacuum gauge is reading a good vacuum. They mentioned that on a commercial scale it is normal to leave the pump running - as I understand it for larger projects it's tricky to find and fix all leaks so you need to have that constant vacuum. This is just the state of play currently. They did mention in their experience leaving the vacuum running seemed more likely to leave pinholes and clamping off the vacuum gave a smoother finish (allowing a little extra resin into the stack after clamping off), so bare that in mind. In the end I got fed up of weeks of chasing leaks so I left the pump running, just so I could perform the infusion, and it worked well. I used a 50/50 fast/medium hardener ratio and was able to turn off the pump after about 6 hrs when the resin had gelled. The EC pump is designed for continuous running under vacuum, and whilst it got a little hot there was no issue. The pump won't draw extra resin out of the stack particularly because once the resin feed is clamped off the pressure inside the stack and externally is equalised and it settles down, but it will continue to draw a bit of air out of the stack. A small amount of resin was drawn up the vacuum line but it didn't reach the catch pot.

I found a resin break quite helpful for slightly slowing the infusion process - with my first attempt without a break the resin reached the vacuum line quite quickly and a lot of areas were left with air bubbles, voids etc. It helps degas the resin within the stack and allows a bit more to be drawn in. Controlling the flow of resin into the stack using the line clamps is something to be mindful of, you can slow the resin into the stack, which may hep some areas to fully wet through and prevent the resin reaching the vacuum too quickly, as well as helping draw more air out. There is clearly a bit of art to this and I can't profess to have any real knowledge of how to control this throughout the infusion though. I think on my final run I may have been going too slowly, some areas were a bit lean and I lost a bit of pot time (resin started exotherming) but I don't really know what the result would be had I gone faster, in order to compare. When to exactly clamp off the resin feed is a bit trial and error again, I think it's just a judgement call on the situation -  I ended up with no choice as the resin in my pot was rapidly curing.

To degas or not to degas? I found degassing a bit of a game changer. As EC mention in the tutorials and advice you don't necessarily need to degas (thus avoiding the extra expense of a chamber) as the resin will be degassed during the infusion process anyway; however, for this I think the stack needs to be near enough perfect (absolutely no bridging at all) and relatively large to give time for all the gas to be drawn out. If any bridging is present (and I found it extremely difficult to avoid - despite my best efforts spending a few hours getting the bag into the corners I still had some) these areas will not be under any pressure so air in the resin will find it's way there and get trapped. For the beginner like me with a complicated part, degassing could be the difference between a successful infusion and a ruined part. Degassing just removed that additional risk - as it transpired I can see I have some slightly thicker resin areas (resin is cloudy) where I did have some bridging so if I hadn't degassed I could still be going at it. It was therefore worth the additional expense for me. Some people may disagree, and for a simpler part where you can be assured of no bridging it may be an unnecessary step. 

Be mindful of pot time. Degassing took about 10-12 mins, and then I had completed about 30-45 mins of infusion when the resin in my pot started curing with a 50/50 fast/slow hardener mix. There was about 200-300g left in my pot, but the part had fully infused and resin had reached the vacuum line so it was largely OK. I had been a bit conservative in my resin quantity calculation, but was worried some of the thicker areas hadn't fully infused. In the end a couple of small areas were a bit lean - interestingly near the resin feed line which I had thought had got a bit rich. I had  left the pot for 10 mins to self degas on previous attempts (as in the tutorial vids), but there were probably some vagaries in temperature that caused a faster reaction this time. 

Small lean areas/voids can be filled in with resin after so is not necessarily game over. 

Do not attempt to demould too soon. On my first attempt I tried after 24 hrs which is the recommended time; however this was in sub-optimum temperatures (garage) and with a 100% slow hardener so I was a bit early and the layers of carbon fibre were delaminating, even though it all felt hard. As a rough guide I subsequently used was to bend the feed line full of hardened resin - if it bends easily with no snap, and is a bit elastic  I don't think the resin is cured enough. If on the other hand it simply "snaps" with a clean break I think it is Ok to try. In the end I left my part about 48 hours even with 50/50 fast/slow hardener and a good room temperature just to be on the safe side.

I had an odd issue with my mould where it didn't seem like the gelcoat had fully cured on the flanges - as a precaution and on the advice of Hanaldo on here, I put down flash tape all around the flange. This worked very well and I would be tempted to do the same even without the gelcoat issue as, although a bit time consuming, it gave an excellent release. The tape is easy to peel up and give an edge from which you can get the tools in. Without the tape on my first attempt it was difficult to find an edge to get the tools in to split the mould without damaging it.