we're going to be actually making the carbon fibre bonnet itself and we're going to be

showing you the latest techniques for making a medium sized carbon fibre panel like this

and obviously we're using the mould that we made earlier in the series. The first thing

that we've done is prepare the surface of this mould using several application of Easy

Lease chemical release agent which we've done as per the instructions for that product and

now the next thing that we're going to do is an optional step but we're actually going

to spray the surface of this mould using a very special epoxy compatible polyester gel

coat. Now it's very important at this point that we make it very clear that the GC50 epoxy

compatible polyester gel that we're spraying here is not the same as a normal polyester

gel coat. Please don't try and use a normal polyester gel with epoxy because it just simply

will not bond and will immediately delaminate. However one thing it does have in common with

a normal polyester gel is the fact that we catalyse it with a regular MEKP catalyst.

We've mixed the gel up in one of the paper cups that's designed for the cup gun so it's

a case of just putting that cup into the holder and then pressing the lid firmly on and then

we load this into the gun by pulling the spring to hold the cup in place. Our gel coat spraying

cup gun is equipped with a 6ml nozzle which when you're spray a material a viscous as

a gel coat is the ideal choice. And we're just going to try and gel a smooth even coat

over the surface starting and finishing off the edge of the part to avoid getting any

drips on the mould. We've now allowed this gel coat to cure fully overnight. Now unlike

a conventional polyester gel coat when this cures it cures with a hard finish and no tack

at all and that leaves the perfect bonding finish for the epoxy resin. The first thing

that we're going to do is just wipe around that perimeter of the mould, clearing any

overspray off this flange and that's so we've got a nice clean surface to stick the bagging

tape onto. We're going to apply the bagging tape all the way around the perimeter of the

mould at this point for convenience really before we put down the bagging consumables

itself. The only other thing that we're going to do before we start is we're just going

to look for any high spots like this on the mould surface which have been caused by a

drip off the gel coat gun and we're just going to flatten those off and that will stop any

of those printing through onto the surface of the reinforcement. We're going for a laminate

of 200 gram carbon, 2mm Lantor Soric and then 2000 gram carbon. Visually of course the first

layer is the most important so we're just being careful to gently drape this 2.2 twill

into the mould. Often what you want to do is get the carbon to just stick slightly in

position and so what we do is just sprintz a very small amount of acetone onto the carbon

and what that does it just slightly activates the gel coat surface and it means that you

can stick the carbon down onto it. And once we've done that we just use a pair of shears

to cut off the excess material we've only got to be just inside of the tape line. And

now this is the Lantor Soric which is an infusion core material and we've cut this just which

a pair of scissors about 25mm short of the edge of the bonnet all the way around and

that's just because we don't want the core material exposed at the edge of the panel.

In this close up you can really see and get a good idea of how the Soric core material

feels and behaves. it's very easy to cut and lay into the mould and then we've got this

fine honeycomb structure around which the resin can flow as an internal core media.

Next we're using some special infusion grade spray tack and just spraying that lightly

over the surface of the reinforcement and then using that to help us position the Soric

squarely and evenly in the middle of the mould which is quite important for us because we

want to maintain an even gap all the way around the edge where the core material ends because

into that we're going to be layering some 200 gram carbon tape. We're using a 50mm tape

here again the infusion spray tack is particularly helpful to allow us to fix that in place and

position it very accurately up against the edge of the soric we certainly don't want

a gap at this point. We're going to build up 6 layers of the carbon tape so that we've

got a match for the thickness of the Soric. So you can see we've got this tape nice and

neatly butted up against the Soric so we're just going to add our next layer, final layer

of 200 gram carbon cloth all the way over the surface and then we're just going to trim

this just like we did before. So over the top of this second layer of reinforcement

we're just positioning a layer of peel ply and we're just going hold this in place with

a few pieces of the release breaker tape. The next thing that we want to be thinking

about is the infusion mesh in the spiral. So we're going to position infusion mesh along

the front here because we're going to be running the resin the shortest distance which is from

the back of the bonnet to the front of the bonnet and then we'll also be positioning

another strip of the infusion mesh just at this front edge and that's going to help spread

the vacuum. We're positioning this infusion spiral all the way around this back edge and

just holding it in place with some of the release breaker. So the final thing to do

before we bag this up is to position the resin infusion silicone connectors. We've got one

at the back here which is the resin feed line so that sits on top of the spiral. And then

we've got one opposite on the front end of the bonnet which sits on this mesh and this

is the vacuum line so we're just going to tape that in place to stop it moving down

and just pierce through. We've added some gum tape pleats around the outside of the

mould and so we're just sealing this bag down to the tape. Now we've got an alternative

video dedicated to the vacuum bagging process so we're not going to go cover it in much

detail here but if I just go over what we've got. We've got the vacuum bag completely sealed

to the tool all the way around we've got our pleats in place ensuring that we've got plenty

of bag, plenty of slack on the bag. At the top of the bonnet here we've got the vacuum

line connected to the catch pot and the catch pot connected to the composites vacuum pump.

And then where we've got the resin feed line at the back of the bonnet this is just clamped

off so what we're going to do is just switch the vacuum pump on and pull a vacuum on this.

Finally before we an infuse we're just going to clamp off this bag and do a vacuum drop

test which is absolutely essential before we can do the infusion. We've come back to

this part now a couple of hours later and we've performed the vacuum drop test and that's

shown us that there has been absolutely no pressure drop in this bag whatsoever and so

that's the point where we can continue. When you're calculating the amount of resin that

an infusion project is going to use of course you do need to make sure that you allow for

the Soric and also the vacuum bagging consumables we've actually got a handy calculator on the

Easy Composites website that will allow you to do this. Now you'll see us do this again

later but what we're doing here is just mixing a 50/50 blend of the fast and the slow hardener

which are available for the IN2 infusion resin. And the reason we do that is this gives us

a medium speed hardener which is perfect for an infusion of this size. it's very important

to thoroughly mix the resin with its hardener trying to do so without aerating the resin

while we do it but any unmixed resin will fail cure in the part. So we've allowed the

resin just to degas just for a few minutes to get any large air bubbles out so what we're

going to do is release the clamp from the vacuum line from when we did the drop test.

We're going to turn on the vacuum pump open the vacuum pump supply and then we're just

going to draw the first amount of resin up to this clamp just to remove any air that

it's at this point. We're just using on of the spare clamps to hold the line on the side

of the resin container and then we just gently unclamp the resin line into the part. You

can see how quickly the resin follows the line of the feed spiral giving it a very even

advance across the part. So you can see how effective the soric is as internal flow media

because this line here of the resin advancing through the part is not being hindered by

the fact that the infusion mesh it actually stopped at this point and this is still, progressing

through the laminate nicely. As you can see the resin has now reached the silicone connector

on the other side of the part and the resin is actually starting to be drawn down the

vacuum line so what we're going to do is just let this carry on being drawn just for a couple

of minutes and that's actually extracting some of this aerated resin and then we're

going to clamp off the resin line. With both of these lines clamped of now we're okay to

turn off the vacuum pump and we're going to leave this part to fully cure. Now the hardener

speed that we've chosen and the ambient temperature that's going to take about 24 hours. With

this part now completely cured off you can here the resin is absolutely solid it's now

time to remove all of the bagging consumables from the mould so we're now going to start

with the bag itself. Just removing the peel ply from the back of this laminate has actually

started to pre release it from the mould already so we know we're not going to have any trouble

releasing it and that really is the sign of a good chemical release agent. So we're just

going to get in and tease it up and it's out of the mould already. With this part out of

the mould you can really see all of this hard work has paid off. We've got a fantastic mirror

gloss over the surface of the bonnet from that clear gel coat we've used. There's no

pinholes whatsoever, there's no bubbles, there's no air inclusions so you've got to be pretty

pleased with that at this stage. Moving on now to the inner skin moulding we're actually

going to be using just two layers of reinforcement on this which is going to be a 200 gram and

a 600 gram because we want this to be as light as possible, although we're going to have

additional reinforcement in the critical areas, which is where the hinges are and also the

catch mechanism at the top. This mould has been prepared with several application of

Easy-Lease chemical release agent just like we've done in previous sections and so we'll

just be laying the reinforcement directly onto that. So the 200 gram cloth is the first

one down onto the mould because obviously this has the flatter finish. We're going to

use some spray tack just on the surface of the mould and this will help us to position

the carbon now it will leave slight imperfections on the surface of the part but that doesn't

matter for the underside moulding that we're working on here. The next step is to put our

second layer of reinforcement down. So in this case we're using the 660 gram cloth.

Now the reason for doing that is that this will actually give us about 0.6 nearly 0.7

mm thickness of reinforcement but we can do it in a single layer which is not only quicker

to put down but it's also considerably cheaper than three or more layers of a 200 gram cloth.

Another light application of the spray tack will just help to position this heavier 660

gram cloth. With both layers of reinforcement down now we're just going to trim away the

excess reinforcement. With all of our reinforcement in place we'll just now go on with a standard

infusion vacuum bagging stack which will be peel ply, then the mesh and then the bag itself.

We're just going to cut the mesh approximately to the right size and then we're just going

to hold it loosely in place and we're just going to take some of the vacuum bagging tape

all the way around the edge of the flange. As before we're just going to add a few pleats

made out of the bagging tape and position these around the edges. The next thing we've

done is position the infusion spiral around the edge and we've also gone down the sides

as well in exactly the same pattern that we did for the top skin. So we're just going

to position the infusion silicone connector on top of the spiral here and then we've got

the other infusion connector ready to go at the front and so on now with the bagging film

itself which we're going to tape down onto these pleats. So we're going to switch on

the vacuum pump start to pull the bag down and position the bag as it goes down. Now

clearly we've sped up time quite a bit in this shot but this really is a very important

part of the resin infusion process and for that reason if you want to learn more about

how to get the bag down properly then please check our resin infusion video and our video

dedicated to vacuum bagging. We've completed the drop test now on this bag so we're 100

percent confident now that there's no leak whatsoever so it's now time to do the infusion

itself. So as before we're going to be using an epoxy infusion resin and for this infusion

because it's going to be taking place relatively quickly a combination of the fast and the

slow hardener together. With the resin thoroughly mixed now and settled it's time to start the

infusion. Start the vacuum. As you can see the resin has now reached the other side of

the infusion project so it's time to clamp off the feed line and we can now clamp off