Intimidated newbie....

General Composites Discussions Articles and Tutorials
#1

Hi all,

Firstly, please excuse the level of this thread, but this is going to be my first time making my own parts. I have watched all of the videos and read all of the threads I can on the subject but I still have some questions.

Firstly, I have made moulds of my bonnet and a scoop I want to make as per the video from “Make a Carbon Fiber Car Hood” post.

I want to start practising on the scoop first as its smaller and as such will be easier (I hope??? assume??). So the questions:

  1. Would laying up, as opposed to vacuum infusion, produce acceptable results? I want it look good, but perfect isn’t a necessity (or, as a beginner, possible!)and vacuum pumps are expensive.

  2. I am worried about the width of my bonnet as it 1.7m at its widest point and I have never seen CF for sale in that width, much less the CF/Aramid weave I’d like to use (I just like the look of it) so can I join more than 1 piece of CF in the moulding process without it looking terrible? Will the joins look stupid? The bonnet is just shy of 2m long, so I am up the proverbial creek as far as using a single piece goes, unless anyone knows how do it without it looking rubbish?

  3. To save cost, I was thinking of practising using glass fibre, is there anything worthy of note different in the process? By which I mean is it considerably easier/more difficult/stiffer/more pliable?

Thanks in advance for any replies. My car is nearing completion and I just want the extra weight saving of some CF bits, and I always like to learn a new skill.

Incidentally, I’m an Engineer and live in Shropshire, England. And love things that go very fast. Or that are very loud. My favourite things are both fast and loud. :smiley:

#2

Hello Tom,

I do not have any formal training but have tried to teach myself how to work with composites. It has been a huge and steep learning curve and I still am constantly learning and sometimes getting things wrong but this is how I found things with regards to wet-laying without vacuum.

Carbon as a material to work with is more difficult when compared to fibreglass, the material is stiffer and wants to lift away from tight radii and 90deg corners though if the mould edge is reasonable long it will hold itself in the corner so to speak. What I mean by this is that for example on a body boot panel, you have a 90deg fold and then the material continue for say 15mm. if you do not extend your mould beyond your 15mm flange then the carbon has a tendancy to lift from the corner or tight radii. I make my moulds with a flange of approx 40mm to overcome this lifting and also it allows me to ‘trim back’ to the parts dimensions.

At first I only made small parts to try and practice and learn on and over time as my confidence has grown I have attempted to make more complex parts, often using split-moulds.

I didn’t bother making parts in grp, I just went straight to carbon as the materials are different enough to make any efforts in fibreglass not relevant to the procedure with carbon, in my opinion.

Starting with the scoop, which is small, is probably the way to go. That way if it does go wrong then you have not wasted material and too much time as both are costly in different ways.

I cannot say anything about resin infusion as so far I have not needed to make parts that way, though I understand that parts are more flaw free rather than how I currently have been making parts.

I have attached some images so that you can see some of the parts that I have made, starting with the earliest efforts up to the most recent. I do not use gelcoat and my parts are not lacquered, it is how they come out of the mould with a little light hand polishing.

The last carbon parts are wet-lay and vacuum-bagged, so far the hardest thing that I have made as the parts are two cast sides and they need to be bonded together so that the sides have a mould finished surface.

The green thing is a mould with quite a large flange the edge of the part is a very tight radii and I am still having issues trying to pull clean void free parts from it…a bit more practice needed.

#3

Hey Oronero, thanks very much for the response! Those parts look excellent, that has answered my question about the possible results without infusion! And, if my eyes do not deceive me, they are for a ducati 848, which is awesome. My jealousness grew when I saw you were in Portugal with a Ducati!!! I think I have managed 250 miles in the last two years in the UK on my 916 thanks to the British “summer”.

You have also got me thinking about a set of CF fairings for my bike now…

Thanks for all the info!

#4

Hey Tom, I go between UK and Portugal, I am in the early stages of relocating over there as I have had enough of our glorious UK summer sunshine.

The parts displayed are a combination of 851/888 and 91-98 Superlight…I have started on the bits for the 916/998 type bikes but have only really started on the race parts as such so far, I will get round to the fairings sooner or later.

A lot can be made using wet lay cloth and with patience you can achieve good results…though don’t get too disheartened when and if it goes wrong as those episodes help you to develop your techniques.

I am currently located in West Yorks, whereabouts are you?

#5

Hi Oronero,

Just wondering if you could please provide more info about that part in the middle… looks like a gear shift or rear brake lever? At the moment I’m trying to think of how to make a side stand, I am stumped on how to make a tubular shape like that so I am very interested to know what kind of mold/process you used!

Cheers for any info. :slight_smile:

#6

mugget it is a brake lever, I knew the thickness of the original items and calculated the required material needed to achieve 1/2 the thickness. The part is made of two parts an inner and outer face which are then bonded together.

I read your post about wanting to make side stands, I hope that your bike doesn’t topple over too many times until you get the thickness required sorted! I hope you haven’t got a heavy bike as I have seen the steel BMW K-series units bend and also the alloy 1990’s Ducati ones do the same. :wink:

#7

Cheers for that oronero! Makes sense to bond the parts, I’m going to look into that… will be handy to get that technique in mind for future use as well!

Haha, no my bike is light, and besides it’s a dirt bike anyway. They’re practically meant to fall over, right? :stuck_out_tongue:

I have been looking around and discovered that hobby supply shops sell CF tube in metre lengths at varying thickness and diameter, could be useful in forming part of the job… cheap as well! I know that I could easily enough buy a stand, but where’s the challenge and fun in that! Besides, I have heard that the side stands on this particular bike are very fragile, so I figure that maybe I can improve on it, or at least be able to make my own replacements.

#8

mugget to make life east try to make a split mould of the original, then cast the part in two parts bonding them together.

#9

Ah, there’s the problem. I don’t have an original to work from. Thanks for that info though, gives me an idea of the right direction to look towards!