Caulking tub surround

Hi, I was wondering if it is possible to add more caulking to new caulking that has dried? We had to recaulk our surround (ceraminc tile) as the silicone caulking had separated from the tub. It's been 4 days and the caulking is too thin in a few areas. Is it possible to just add more or do I need to remove it and start over again? we are using DAP Tub & Tile adhesive caulking.
thanks!

I wouldn't use any latex Chaulking. They tend to promote mould growth. Use a true silicone product (smells like vinigear)

You really should remove the dry silicone and start from scratch. Clean and dry all surfaces before siliconing.
Keep in mind , silicone has a maximum life expectency of 2 years

I was afraid of that, oh well better to do it right.
thanks!

Krow cop is exactly correct. Hello, for what it is worth here is my take. I do allot of recaulking and the first thing I do is to make sure what I am caulking is completely prepped clean and free of any old caulk or foreign matter. I like to use denatured alcohol to break the old caulk down and for ease of removal. When I open my caulk I keep the opening as small as possible, it makes it allot easier to control where the caulk goes. You should do all of your narrow work and if you have any large gaps do them last and open the caulk tube tip accordingly. Finally when cleaning caulk be sure not to break the bond between the caulk and tile. The edge of the caulk is thin and the adhesion is easily compromised with excessive pressure or abrasion. If this happens the caulk will trap and hold moisture that will initiate mold and mildew growth. You can see some of my handy work at Precision Grout & Caulk if you have a question email me and I will do my best to answer it.

Groutman and krow are right. You have to get that old caulk off, and clean the area down. The cleaner the surface, the longer it will last.