For extreme 3D we suggest 40 degrees on both surfaces. With casual flying all that is needed is 40 degrees on one surface and 10 on the other and it doesn’t matter which surface gets the different angles. All of the surfaces are top hinged with Blenderm tape, cut your bevels with a new blade, slide the two halves together and tape Next, fold the surfaces back onto each other and tape the exposed beveled edges on the bottom, this will give you the strongest hinge. Blenderm tape, manufactured by 3M, is the preferred tape for all Depron foamies, it sticks well and holds up to quite a bit of abuse. Our foamies are cut with a high speed router and are sold without beveling. Over the years many customers have requested an option to have the surfaces pre-beveled, making hinging easier. We now offer beveling and taping as an option.
Remember, it is best to bevel before you paint.