  R Coronae Borealis (RCB) stars are rare hydrogen-deficient carbon-rich
variable supergiants thought to be the result of dynamically unstable white
dwarf mergers. We attempt to model RCBs through all the relevant timescales by
simulating a merger event in Octo-tiger, a 3D adaptive mesh refinement (AMR)
hydrodynamics code and mapping the post-merger object into MESA, a 1D stellar
evolution code. We then post-process the nucleosynthesis on a much larger
nuclear reaction network to study the enhancement of s-process elements. We
present models that match observations or previous studies in most surface
abundances, isotopic ratios, early evolution and lifetimes. We also observe
similar mixing behavior as previous modeling attempts which result in the
partial He-burning products visible on the surface in observations. However, we
do note that our sub-solar models lack any enhancement in s-process elements,
which we attribute to a lack of hydrogen in the envelope. We also find that the
Oxygen-16/Oxygen-18 isotopic ratio is very sensitive to initial hydrogen
abundance and increases outside of the acceptable range with a hydrogen mass
fraction greater than $10^{-4}$.
