Hi,
I tried to create an heavy duty hinge with the carbon starter kit but I came across the same mistake every time apparently.
I "paint" a glass surface with the PVA release agent and let it dry for 20 minutes then I applied a layer of epoxy resin mixed with the epoxy hardener ( ratio 2/3 epoxy and 1/3 hardener) and let it dry for 2 hours.
I weight the number of CF sheet I will use and the following relationship to decide which amount of resin I should:
Epoxy Hardener weight = CF weight
Epoxy Resin weight = 2 * CF weight   

I lay each layer of carbon one after another "paint" the resin on it and remove the excess resin from time. Leave it alone for the night.

First: no way I can separate the CF from the glass surface. Should I leave the resin solidify for precisely 8 hours or "at least" 8 hours that may explain why the two are "glued" permanently together.
 
Second: once I had a strange reaction in the pot where I mixed the epoxy & the hardener. It started to get really hot with fumes and it solidified almost instantly. What did happen? how can avoid that?

I'm aware that for an hinge resin infusion is more likely the best course of action but my lack of success with this technique  and the entry cost prevent me to use it.

Thanks in advance.
Benji

Hi Benji,

I have looked through your order history and you have had a laminating kit from us which uses our EL2 laminating epoxy resin. This has a mixing ratio of 100:30 by weight. Ie you need 100 parts of resin to 30 parts of hardener.  It is critical that you get the mixing ratio as accurate as possible other wise you will have curing problems.  a part cured resin or undercured resin will grip the mould quite well making it hard to remove which might partly explain your demould problems.

However, Hanaldo is spot on with the release agents.  Glass can be tricky so unless you were 100% sure you had a good even layer of PVA then I suspect the part has stuck as a result of the PVA layer not being even.  Epoxy sticks to glass VERY VERY well which is unfortunate in this case. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant