The first step to Carbon Fibre

[scarfacehugo]

The mould looks good. Are you going to vac bag it when you lay up your carbon? I am sort of trained in composites (including CF) but have only limited experience. If you need any tips or information I might be able to help but no guarantees! We only use glass fibre but the priciples are the same.

Thanks for your offer, mate!

I've been trying to laminate some other parts and the results are not the best ones, specially when the parts are complex in shape.
I'm going to try vacuum bagging, without having to buy the vacuum pump, the fittings, the hose and all that stuff. I'm using the storage vacuum bag with my friend "Henry" and hope for the best. If this system fails, more investment is on the way.

Is there any other cheap vacuum process you might know of?

[japes1275]

The storage bags might work quite well. If not then you will have to use the sort of stuff we use which is a green film that you just cut to size and form the bag with bagging tape. If you want the curing process to speed up you can heat it up, not really possible with the storage bags as they won't take much heat. When you start pulling the vacuum don't just rely on that to form it to the shape, press the bag into the tight corners with your hands as it forms. Good luck!!

[scarfacehugo]

The storage bags might work quite well. If not then you will have to use the sort of stuff we use which is a green film that you just cut to size and form the bag with bagging tape. If you want the curing process to speed up you can heat it up, not really possible with the storage bags as they won't take much heat. When you start pulling the vacuum don't just rely on that to form it to the shape, press the bag into the tight corners with your hands as it forms. Good luck!!

Thank you so much for your input.

I'm ordering this week release film and breather fabric to wrap the part in and the storage bags.

I'll let you know how it goes next weekend.

Cheers

[Snaphappy]

I've been watching similar stuff on youtube
Great job

I think Davsato uses CF at work I'm sure he'll pass on tips

does it not need heat curing in an autoclave though?

[scarfacehugo]

I've been watching similar stuff on youtube
Great job

I think Davsato uses CF at work I'm sure he'll pass on tips

does it not need heat curing in an autoclave though?

Not at all. An autoclave creates vacuum and high temperatures. That means a faster more precise curing process, but I dont think it affects the stucture in any way.
I wont be making structural CF parts, only covers and aesthetical stuff.

[japes1275]

Thats right, some of the bits we work on wouldn't fit in most autoclaves and anyway our taxes can't afford to pay for one!!

Any form of heat will speed up the curing process but it is also true that it might effect the strength of the part if not cured correctly and no vacuum used. When you heat it up the resin becomes less viscous and flows better into all the tight corners. Sometimes we have to do jobs outside and in this sort of weather it would take days to go off. We usually speed up the cure by using a hot air gun on smaller jobs. Even a hair drier would make a difference! Just make sure when you have a go you do it in a warm room not in a cold garage.

I'm no expert though and most of the jobs we do are just repairs to cracked fibreglass panels - I keep meaning to have a go at making some parts for my Hillclimb car but never get round to it! Plus I would have to buy the carbon cloth as we don't use it!

[Lumiya]

Not at all. An autoclave creates vacuum and high temperatures. That means a faster more precise curing process, but I dont think it affects the stucture in any way.
I wont be making structural CF parts, only covers and aesthetical stuff.

Actually an autoclave is just the heat bit and not the vacumn. You tend to vacumn and then cure with heat afterwards. Few autoclaves have built in vacumns but they are specialist at curing resins that need the the vacumn, the pressure though is equal within the autoclave and has no bearing on mold pressure.

We got a high pressure/capacty lab vacumn pump that we're just sorting out for the job, gotta sort out the filters (resin/fibre tends to ruin the internals) and a res tank as well as the taps (no need to keep the pump running once down to the required pressure.

Remember though that without the heat the resin/CF bond isn't gonna be that strong unlike resin/glass (something to do with the surface of the CF) hence the oven can be crucial to stop it from delaminating

[Arf]

Hi,
I'm up for 2 if they come out fine and the price is right .

Regards
Arf

[BobA]

As far as I know, and I stand to be corrected, there are two distinctly different processes of making carbon-fibre products.


Wet Lay, as is being done here is mostly similar to fibre glass and of similar strength. Ideal for cosmetic pieces, but not for structural or load bearing items. No real weight saving over fibre glass, but obviously a much nicer appearance.


Pre-Preg, where the actual material is much thinner, and the sheets are pre-impregnated, laid in a pressure/vacuum mould, and cured in an autoclave. These parts are MUCH lighter and MUCH stronger, and can be used on load bearing assemblies.



Good luck with your project, nice pics of your superclean workshop, and can't wait to see the finished articles.



Bob

[Jenna]

ooo look at you with all the fancy lingo....

commersial CF is a different ball game to to anything you can do on a DIY level... its a different material using a different resin in a different way.

looks good, mucking about with GRP can be addictive so be aware... and when its adictive it gets expensive!!!

you mention vacumm bagging, from my experience the bagging material is key to getting in the corners, these days i use a thin material and not the thicker ones and a thicker mat.. costs more to do but the results are way better if thats any help.