Pleased to report that with helpful advice from your tech team and some forum members I have now successfully made up 6 flat c/f panels in 195 gsm varying from rectangular 400 x 400 mm to triangular 2200 x 450mm by resin infusion. All have eventually come out without voids (yipee), there was some scrap. They only worked well once I heated the layup table to 22c, and heated the resin as it flowed with a hot air gun. I did use a lot more resin than in your tables, but the surplus came off in the peel ply. My panels are 0.35mm thick.

Now can you you help me with sticking these on my grp boat?  I have coarse sanded all the grp, 80 grit. I cannot control the temperature which is ambient in a big steel shed, currently 3c and 65% humididty. I therefore cannot use epoxy the glue them down, because any minor  uneven heating / cooling causes ripples, I have tried. The surface is compound curve, just, but I have formed the panels dry, by heating them till flexible and taping them down to cool. (It works!) I favour using pu 18 adhesive as it is flexible and waterproof, but how on earth do I get an even thicknes of such a thick sticky adhesive over such a big area??? and how do I keep the panels even on top of the adhesive?? Any advice and or clues would be greatly appreciated.

Can you get a photo of the deck ribbing and the gap between them?

The 2mm deflection in 500mm is no problem whatsoever.

Of more concern is the gap between the deck ribs. The way you describe it, it seems like you are laying the carbon sheet over the deckribs meaning it would naturally sag into the gap between sheet and deck material.

Can you take a photo or describe what you mean and  I will endeavour to give some more advice.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hi Warren. Sorry not to be fully clear.  The boat is 30 years old, GRP moulded decks laid in female mould and ribs bonded  in place, then bnoded on to the hull. As it is a racing dinghy/sailboat the decks are very light and we are not supposed to stand on them.  They have softened a bit since new, and the idea of using c/f was twofold. Principally to make awesome decoration, secondly to put back a little of the lost stiffness. I have taken out the very slight sag between the ribs, about 2mm, with epoxy and glass bubble filler, and sanded fair. There is a curve from centre to side, 35mm over 450, and a very slight curve for and aft, not measured but about 10mm in 1800. That causes a slight springiness in my panel which is .35mm thick.  When I try and stick it down it goes on ok, especially when heated with hot air gun. I am working in a large steel workshop, unheated except for my fan heater which I direct under the deck. Surface temp about 15 deg max. I am not allowed to leave the heater on when I go home, fire regs. At that stage everything looks great.  It's only over night that the bubbles/wrinkles appear. That is what leads me to think the epoxy is not grabbing and setting fast enough. Also I was able next morning to lift the edge of my wrinkled panel with a blade and then literally rip it off, so definitely not cured. I have rescued and cleaned all the residue off thank goodness. I can't photograph the boat as is till Monday and my only pics are 14mb which won't upload .Writing to you guys does really  help the thinking by the way, it clarifies the issues a bit.  I guess the real question is in the conditions I am forced to work under will PU 18 combed evenly and then either squegee the panel in place and or then vacced down give me a better chance of success? My squegee is long enough to span two ribs, 10mm thick covered in 5mm hard foam and towelling to prevent scratches. Similar boat pic above, will give you an idea of the curves involved. Welcome by the way, and thanks. Mike.