Hi all,

At last I have another car - project on the go

And immediately, it's raised an age old problem I have with Carbon.

the part I'm trying to make is 1.7m wide, so there is no choice but to have a join in the visible surface. the part is to be wet-lay.

I can get an 'okayish' join in Carbon but never that pin sharp join you see on professionally made pieces - anyone got any magic tricks to ensuring there are no stray hairs or tatty bits of edge?

ta!

Good question, I also would like to know!

Surely you would need to overlap the joint to maintain strength, so would it be possible to get a bigger sheet. What are the biggest sheet sizes.

You can get bigger sizes but not big enough and they're always special order (which means buying an entire roll) You do have to overlap and that isn't a problem, but the join line is for me!

There are a few tricks, but as little handling as possible is key. You could also use spray starch, to help bind the mat together and hold any loose bits (I usually apply masking tape to the edge before cutting it, but if you need to use the edge, then that wont work.

Roll out the material you need very carfully. and straighten/tighten it. Spray it will starch to set it. Then carefully roll back up. When it is time to use it, unroll it on the job, doing the final alignment. The problem is, with wet lay up, things will move - if you were using a vacuum assisted process, that would tend to hold it all in place...

The alternative is, you wash the surface you are laying up onto, in resin - the resin will hold the material in palce with minimal sag. If you are happy, follow the previous steps above, but use the additonal resin wash, to help wet out, and holding of the materials.

Dont beat yourself up over it - the pin sharp joins you see on the high end sportsd cars etc, are the results of using prepreg, where you can be very accurate with your edge details.

I know little about carbon laying but could you not fold the edge to create a sharper finish.

Maybe try youtubing the carbon lay process and see if you can watch the part where they finish the edges of the sheet.

TWR used to use black gelcoat lines around the edges to hide the joins on the Volvo BTCC cars. Sounds crap, but look ok.

if you try being as neat as you can and if your joins look pants, add a sparyed line over them and clearcoat over the top.

alternatively, stop being a tart, it aint a Zonda