I've mulled this one over and here are my random thoughts.....

Most epoxies are a product of epichlorohydrin and a bisphenol to generate a polymer chain of a certain molecular weight.  The chain length is related to viscosity so I dont see why different resins wouldn't be compatible.  The hardener is a polyamine or polysulphide used to cross-link the chains.  Both are simple nucleophilic reactants so should react with any chain thats around.  I suspect that if properly mixed you'd end up with a resin with properties that are inbetween those of the starting resins.  If they aren't mixed then I'd choose the lesser properties as the benchmark as there will be areas of this in the laminate.  Not really a game stopper.

Obviously thsi is just my ramblings so I stand to be corrected.

I do this all the time and I have never had a material not cure or fail in any way.




Fill voids with epoxy glue or filler and laminate straight over with an epoxy laminate.

Or I also mix pre preg materials, different brands with different resin systems. Always works.




I am sure some may debate it but hey I'm not building aeroplanes!

Best thing to do is to test it. 

To specify the problem more, i do not want to cure a layer on top of another layer.

I'm not exactly sure what you are trying to do but I have used two different resins in a project before.  I needed a moulding with a flexible lip but a rigid main body.  I layed up EF80 with a peel ply on top and let it cure.  I removed the peel ply and layed up in some normal laminating resin on the main body only and again layed on peel ply and let it cure.  I then layed up with EF80 again over the whole area and let that cure.  The standard resin made the main part rigid but the flexible resin meant the lip part remained flexible.  I dont believe you can mix resins in the liquid state.

Hello,