Name: 如何做一個碳纖維汽車引擎蓋/引擎蓋--第1/3部分。 (How to Make a Carbon Fiber Car Bonnet/Hood - Part 1/3)
Uploaded: 2021-01-14T06:47:39.000Z
Duration: 21 min 24 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

關係子句

Hello and welcome to this Easy Composites video tutorial. In this series which is probably

the most ambitious we'll ever take on we're going to be answering the question that we

get asked more often than any other, which is how to make you're own carbon fibre vehicle

panels like this car bonnet that you see here. In the tutorial we're going to be showing

you every single step along the way including making the mould, making the parts, bonding

the parts together, trimming and finishing to enable you to make your own incredibly

light, incredibly strong perfectly finished carbon fibre panels. We really hope you enjoy

it. The first step in our process is to take this original steel bonnet which we're using

as our pattern. We're going to add barriers all the way around the outside of it so that

when we make our mould we actually created a mould with a flange on, and that flange

will add stiffness to the mould and it will also give us plenty of opportunity to position

the bagging consumables and things for the resin process. Before we actually apply any

barriers to this part we're just going to take the opportunity to put down a full background

layer of release agent. We're using Easy Lease which is a chemical release agent and of cause

this is what's going to stop the gel coat from sticking to the part but while we've

got the bonnet in this state it's much easier to ensure that we've got everywhere covered

and then we'll probably do another application later on. Making barriers can be tricky. The

technique that we've developed is to use corrugated signboard for the barriers themselves and

the bond those to the underside of the part using hot melt glue. So the first thing to

do is to use masking tape to actually make a template around the edge of the part and

then we'll transfer that onto the signboard and cut the barriers themselves. So with the

masking tape all the way around the edge of the part it's a case of just marking up where

we're actually going to make the barrier pieces in separate sections and we also at the same

time just draw on the angle that we're going to cut the barrier sections at and finally

number them so we can identify them. So we're going to have a cut line here and a cut line

coming off at this angle here. Then this will all be one piece and we'll have cut lines

on the barrier about there. The masking tape comes off the part extremely easily. So we're

just going to start it off and then cut it into the parts that we've identified, being

careful not to rip the tape. So we're transferring this line here onto the board. We know the

angles that we want to make the barriers at. Once we've marked out all these templates

we're just going to cut them out with a sharp knife and then position them around the outside

of  the part. we're working on the underside of the bonnet now where we're going to be positioning

this barrier. Now the way we're going to do that is we're going to apply masking tape

to the edge on the underside of the bonnet here and then we're going to be using hot

melt glue on the masking tape and then on the barrier. the reason for the masking tape

is so that this barrier is quite easy to remove when we're done with the process. So we can

get started with that with the masking tape. We've got masking tape all the way along this

top edge so now it's time to use hot melt glue gun we're going to just put a bead of

glue all the way along the top edge and then stick the barrier to it. We've now flipped

this bonnet over just before we do the wax we're actually going to use a release tape

to actually just seal these joins, or a breaker tape and that's just going to prevent again

any of the gel coat from running down into the gap. So we just take the tape and tape

the seam and because it's a release tape the resin and the gel coat won't stick to it.

So the next step is to us a yellow filleting wax to actually create a bead all the way

around the edge between the bonnet onto the flange and what that will do is stops the

gel coat from running under and locking in and also gives us a nice smooth transition

so that when we've got the mould the parts themselves are going to release nicely and

they're not going to get caught up or mechanically locked on this edge. So we've put the filleting

wax all the way around the outside now and you can see from this close up what we want

to do is always be sure that when you put the wax down you've got what's called a draft

angle and that's going to mean that when we remove the part of separate the part and the

mould that there's not going to be a mechanically lock. We're now ready to put the proper coat

of release agent onto the bonnet and we're going to apply two coats of the Easy Lease

all the way over the surface of the panel. Now the filleting wax doesn't requite a release

agent and in fact will actually get dragged off by the release agent if we're not careful

so we're not going to apply any release agent to the wax. We are going to apply the release

agent onto the barrier itself just in case there's any contamination. It is made from

polypropylene so it shouldn't stick but just in case it does we're going to give it a coat

over as well. We've now left this a good half an hour to fully dry off and we're actually

going to apply two coats of wax all the way over the top of this the steel bonnet part.

Now usually we wouldn't use a wax on top of a release agent. A chemical release agent

generally works on its own however in the case of going from a pattern to the mould

itself we want to be absolutely sure that we're not going to have any problems with

the release and so having the chemical release agent and the wax although it's a slightly

unusual combination is going to ensure that we do have no release problems. We're now

buffing off the wax having left it about five or ten minutes and you just really want the

lightest possible pressure when you're doing this just using a micro fibre cloth here and

just skimming over the surface and you can see the shine start to emerge. Right so we've

now left the wax to fully harden off which is roundabout half an hour or something like

that and so it's actually time to make the mould itself. So we're going to be using a

very versatile tooling system called Uni-Mould and the Uni-Mould system comprises a tooling

gel coat which is a vinylester tooling coat. Now the reason we're using vinylester is that

that's actually compatible with polyester resin, vinylester resin but most importantly

for us epoxy resin and it will guarantee an excellent release of the parts out of the

mould which you wouldn't get with a normal polyester gel coat. The Uni-Mould system then

uses a coupling coat which is reinforced coupling coat we actually add a lightweight chopped

strand mat in with that which forms the connection between the tooling gel and then the tooling

resin itself. Applying the gel coat now we can do this in either two thin coats or one

thicker coat. We'd be targeting in a single thick coat of a roundabout 0.8 mm. Now for

a bonnet this size we're looking at mixing up a roundabout 700 grams of gel coat if you

mix up too little and you come up short you can always mix up some more. We're using normal

MEKP catalyst and a ratio of about 1.5 to 2 percent. So for 700 grams of the gel coat

that would obviously be 14 grams at 2 percent of the catalyst. Applying the gel coat is

totally straightforward covering it and we're going for that approximately 1 mm which is

a reasonably thick application. We've now allowed this gel coat to cure to the right

point. It's certainly very much firmed up but it's still got a very slight level of

tack which is the right point for a gel coat. So in the Un-Mould system it's now time to

add the coupling coat. As we say we've got a light chopped strand mat, we're using a

225 gram here. This is really as heavy as you would want to go at the coupling coat

stage, you could go lighter and we're going to be wetting this through with the coupling

coat. Again this is catalysed at a ratio of about 1.5 to 2 percent we're going to be catalysing

it about 2 percent and we're going to use a full kilo on this layer. When the coupling

coat has been fully catalysed it does actually change to a darker colour so you can tell

it's ready to go. Now when you're working with he coupling coat it's just like any chopped

strand laminating so you apply the resin to the part first and then drop the glass mat

down onto the resin and then wet it through from above. The light chopped strand provides

reinforcement at this early stage but because its a light mat it's very easy to get it down

into the contours of a mould which ensures that you're not going to have any voids between

the gel coat and the main tooling reinforcement and the coupling coat itself chemically is

designed to act as an interface between this vinylester tooling gel coat and the tooling