Hi Folks

 

I hope you can help. I am considering making two side frames as shown in the attached sketch from carbon fibre using resin infusion.

 

The overall size of each is 62cm x 54 and 3cm thick, each made as a two items and glued together.

 

The idea is that I make the item in plywood,  split it and take a fibre glass moulding which will be used to form the CF frame.

 

As I say I am considering resin infusion and the plan is to pull the vacuum as shown in red and feed the resin through the three green arrows. Either that or pull the vacuum from the four extremities and feed into the widest vertical part.

 

Any thoughts?

 

Chris Hillman

Hi,

I have a simmilar project as yours, please check on this:

http://www.talkcomposites.com/1694/Wet-Lay-Up-or-Resin-Infusion?Keywords=Infusion%20Mirror%20Rearview%20%20Project

All the best

Leon

Hi Chris,

Thanks for the post; this looks like an interesting project.

Making 'solid' parts like this frame (or like the rear wing that Leon linked to) always requires a bit of extra thinking about because there are more options of how to go about it. Your suggested method of resin infusing both sides using two different moulds and then bonding them together is probably the most conventional but it's worth (if you haven't already) considering other methods such as making the frame from a core material such as Closed Cell PVC Foam or Low Density Polyurethane Foam (which can be easily shaped and would weigh very little). You could then wrap carbon cloth and epoxy resin around the core and then consoldate the reinforcement using a Composites Shrink Tape. This method certainly wouldn't give you the perfect surface finish straight off that using a mould would but it would be quick and easy, requiring no mould at all. Another option is a 'hybrid' between this first suggestion and your method which would be to make a foam core, wrap carbon and epoxy around it and then press that frame into the bottom half of the split mould before adding the top half of the mould and then clamping them together to consoldate the reinforcement. This would give you a better surface finish that the shrink wrapping process although not as good as infusing the two halves separately.

These are just ideas worth a mention though, infusing two halves is also a good way to go although it leaves you with the tricky task of bonding the shells together and maintaining adequate strength.

the plan is to pull the vacuum as shown in red and feed the resin through the three green arrows. Either that or pull the vacuum from the four extremities and feed into the widest vertical part.

The vac point (red arrow) looks to be fine. Regarding the resin inputs, remember that the infusion spiral will really spread out the resin input very well and it's not often necessary to have more than one resin input. I think I would run a sprial from just about the bottom left green arrow to around by the bottom right green arrow and then sit the infusion connector on the spiral in the centre of the bottom edge. This will give you adequate resin feed. I wouldn't worry about the higher right green arrow, I'm sure the resin will get to there before it gets to the top red arrow.

I hope this helps and look forward to seeing how you get on with the project.

Best regards, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Thanks Matt

I had thought about making a core and pressing it into the fibreglass shells, but I lliked the idea of using vacuum infusion!

Thanks for the advise regarding placement of the feed lines, I shall take photos as I proceed.

Chris