A few days ago I scraped out all of the old caulk around our bath, cleaned and dried the area then applied an anti-mould bathroom sealant (neutral silicone). I don't think I applied a thick enough layer. There are no gaps but if you look closely you can see a few cracks in the sealant. Would I be able to apply another layer over the top or do I need to scrape it out and start again?
Unfortunately, silicone doesn't stick to silicone. So unless you can somehow bridge the entire bead of original caulk, you're stuck with the hard work of taking it all out again.