I just did my handrails and caprail with Semco teak sealer. Removed failing varnish with heat gun and scraper, sanded with 60 grit, and applied 2 coats of Semco. There are various shades available, I used a 50:50 mixture of Cleartone and Natural. Semco will never peel, wash and add a coat every year. I will report back on how it goes. I think it looks nice, not like 8 coats of varnish, but I can spend the next two weeks boating instead of varnishing! Just another option, paint will eventually peel like varnish, also hard to go back to varnish, Semco could be removed by using two part teak cleaner/brightener and ready for varnish if so desired.
Best of luck,
Scott