I have a.mould that has a few corners in it and the age old problem I am having a real problem getting carbon to stick around the mould corners. I have used fusion fix to stick the first layer in place apply the resin but as soon as I put on the second layer, it all goes wrong.
I have tried letting the first coat cure, I have tried using a powder based chopped strand for the second and third layer's just so I can see if the mould is correct. better obviously because the reenforcement strands can be moved around. However if I want to use carbon, I am going to struggle. It's all down to experience I know but I just can't seem to get the right technic.

Any ideas, no matter how silly would be welcome.

One I thought about was can I use spray tack on all the layers of carbon,then resin the whole lot?

Can I use a lighter grade of carbon 100g or something and just keep on putting on layers?

I want to make a part around 1.5 -2mm thick so perhaps 1 thin layer, a I.5mm mat but only on the flat areas, then another thin layer of carbon over that.?

Thanks in advance.

If you go for resin infusion, you can use a spray tack on each layer of fibre.

Have you got any photos of the mould?  Might help us to give more specific advice.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Make sure you use a twill rather than a plain weave cloth, as this has better drape characteristics.

Thanks for your comments, I am trying to upload a photo of the mould but struggling a little...

In the meantime, I have thought about using the origianl item I moulded from to help 'press' the carbon into place.

A bit of peel ply on top of the carbon layers and a good weight.

I thought if I used peel ply then I could also put another layer or two on after the first has cured.

Silly idea or worth a go?

Regards

Some parts just aren't suited to wet-lay. Is there a reason you dont want to use vacuum? For wet-lay all you need is one of those vacuum bags used for vacuum packing clothes and a household vacuum cleaner will give you more than enough vacuum.

I am saving up for a vacuum pump but I had thought of the cloths vacuum bag. So do you wet lay all the layers , cover with peel ply on, put it in the bag, draw out the air and leave to cure?
Or do it in stages?

Nah that's pretty much it. Obviously you wet it out layer by layer, dont try to put all the layers in and try to wet it out all at once. But you can do many layers in one hit, no need to do stages.

If you want to get rid of some excess resin, you'd go peel ply then a perforated release film and then finally breather cloth. Then as you pull vacuum, the excess resin will squeeze out into the breather so you can peel it off layer. This isn't necessary, you can just use the vacuum to hold things in place.

I have a couple of thoes bags, so I shall give that a whirl in the next few days and let you know how I get on.

Thanks for you help

Is it a cosmetic carbon part?

If not then you can add a small amount of a thixotropic filler to the resin which will make it a little more sticky. This helps it stay in place much better but the additive may change the colour a little??