A thread belongs to the OP (original poster). Trying to take over someone elses thread is called hijacking, which is not allowed at All About Circuits. I have therefore given you a thread of your very own.
Electrolytic capacitors are usually not used with triacs because triacs are usually used with rather high voltages and they don't need a lot of capacitance in their snubber circuit. Cheaper and safer to use film caps or ceramics.
ps, triacs are used with AC current. A non-polar electrolytic is rather expensive.