I'm looking to cast a table top - the top will be 50% a plank of waney wood, 50% epoxy (or similar).

I plan to make a decorative frame, place the plank within it set to one side, and lay them both on a polypropylene base sheet, then pour in a resin to fill the 2nd half of the frame. The surface of the wood + frame and composite will all be the same height, i.e. the wood won't be submerged in the composite. Total volume of composite will be about 12 litres. I have a few questions though:

- Which composite would be best for this application? (needs to air cure as clear as possible, I have no access to vacuum systems etc).
- Should it be poured in layers? Or is one go ok? It will be quite a large area, but only 1" deep.
- Would any releasing agent be needed on the polypropylene sheet?
- How strong is a butt joint between a composite and wood? Should the wood be "keyed" or similar to improve the bond?

Thanks very much!