"Was the grout between the tile and the tub?"

Yes, where the base of tile meets the tub. I wondered about that. I have limited experience, but can't recall ever seeing that before.

Many thanks for the advice, Brickeyee. This is going to take more time than I anticipated.

Take care -- Cathy

Any grout between the tile and tub should be removed so pull it out with the old sealant and re seal the joint with the most expensive 100% silicone sealant you can find, not just tile and tub caulk.

It is necessary to thoroughly remove all of the original silicone in order for the new silicone to stick. Unfortunately that is extremely difficult.

Here are some suggestions from GE:

"It is VERY difficult to remove silicone from a surface. However, if you must remove it, follow the suggestions below.
To remove silicone sealant from surfaces, first remove as much as possible by cutting/peeling/scraping excess sealant from surface.

* For ceramic tile, marble, Formica, fiberglass, etc., use 100% mineral spirits (turpentine) and a non-abrasive scouring pad. Test solvent on a hidden area of the surface to ensure that discoloration will not occur. If discoloration does occur, contact the manufacturer of the surface for further assistance.
* For glass surfaces, use a razor blade to remove as much as possible, then apply mineral spirits. Remove excess as much as possible, then apply mineral spirits. Remove excess with a towel or other suitable cleaning utensil that will not mar the surface (such as a non-abrasive pad).

NOTE: For surfaces such as hard plastics or painted surfaces, including cars, use rubbing alcohol and a soft cloth. Do not use mineral spirits. Only use these solvents in a well-ventilated area and follow all safety precautions and instructions listed on the product label. Material Safety Data Sheets for GE Sealants & Adhesives products are available upon request. Similar information for solvents and other chemicals you choose to use with GE products should be obtained from your suppliers. When solvents are used, proper safety precautions must be observed.
On Rough, Porous Surfaces:
To remove sealant from a porous/rough surface, (concrete, brick, wallpaper) remove as much of the sealant as possible (same as smooth surface). If necessary, use a wire brush in conjunction with mineral spirits. NOTE: We do not recommend use of a wire brush to remove sealant from wood surfaces, as doing so could damage the wood. Also, mineral spirits should not be used if the wood has any type of finish on it. Test solvent on a hidden area before applying. Mineral spirits are flammable and should be used away from sparks, flames and other sources of ignition. Only use these solvents in a well-ventilated area and follow all safety precautions and instructions listed on the product label. Material Safety Data Sheets for GE Sealants & Adhesives products are available upon request. Similar information for solvents and other chemicals you choose to use with GE products should be obtained from your suppliers. When solvents are used, proper safety precautions must be observed.
NOTE: There is nothing that will dissolve silicone.
NOTE: If reapplying silicone to the area, remove the old sealant. Then clean the area with a disinfectant if mold or mildew is present, apply rubbing alcohol. Let the area dry before re-applying silicone. Do not use soap to clean surfaces to be sealed because silicone will not adhere to surfaces covered with any soap scum."

I suspect this is a far more difficult job than you yet realize.

Many thanks for the additional information, macv! In particular, instructions for what to use for each circumstance -- great!

I was wondering about mineral spirits, except this bathroom has no ventilation except for a rinky-dink fan (add a teenager, hence the mold/mildew.)

I ended up googling caulk solvents and found a 3M product that seemed to get good reviews and was recommended by Popular Mechanics in its How to Remove Caulk - 6 Easy Steps. I think I just used DAP kwik seal. I would really like to just remove the caulk as a first step and then check the grout.

"I suspect this is a far more difficult job than you yet realize." Yep. While I thought I was mid-way on the caulk learning curve, I am at the high end knowing when to stop due to past screw-ups. Because it took me 15 minutes to remove about 3", I walked away and came here. Now, I'm at least committed to fixing. Whatever I do, is going to take more time than anticipated.

Thanks again for the great additional information. I'll report back if I have any success.

Take care - Cathy

If it is DAP Kwikseal, it is not silicone sealant but an acrylic latex caulk with some silicone added to make it a bit more flexible and last longer. If it could originally be cleaned up with water and be painted, it doesn't contain much silicone and shouldn't be difficult to remove.

If the product only lasted a few years I don't recommend using it again. The most flexible and longest lasting sealant is 100% GE silicone but it requires some skill and experience to install neatly.

"100% mineral spirits (turpentine)"

Someone should tell DOW that mineral spirits and turpentine are NOT the same thing.

Mineral spirits comes from distilling crude oil.
Turpentine from boiling trees for extraction.

Most flooring outfits have silicone caulks in a wide variety of colors where you can match up your existing grout with that of the colored silicone. Remove it all, clean it out and rid of any loose debris, find a matching colored silicone to go with your existing grout, no worries. I know easier said than doen, but persistence pays off. Never grout up to the tub, ever again. Hear me? Never again! The same applies to baseboard if your tile butts up against it, dont grout the joint between the tile and base, but rather use matching colored silicone.

i would like to know why the caulk that you put around the tub turns "dirty" looking in a matter of weeks after you put it on. it is regular tub tile but it is just awful looking. a oerson could do every couple of months. any suggestions on how clean it or a different product to use? thanks in advance.