I have a gorgeous shower unit that looks awful because the sealant has turned black. I will have to remove this and reapply some more. Hopefully this won't happen again.
I live in a hard water area and the water is full of lime. Any tips on how to remove the sealant without scratching the interior and also what sealant will not go black?

Many thanks for any replies.

Tell us more about this "gorgeous shower unit that looks awful".
I'm assuming that this is a manufactured base and enclosure and not a custom tile shower. Correct?: What type of "sealant" and what does it seal?
How long has the unit been in? Well or city water?: Is it black in places or all over? To answer you we need all the details you can give us. I'll wait on your reply. Regards, n tom

Lots to tell us. If you are planning on a silcione caulk I'd recommend Daps Kwik Seal Plus. This stuff has a mildewcide built into it. DAP Products - Caulks and Sealants - DAP® KWIK SEAL PLUS® Premium Kitchen & Bath Adhesive Caulk w/MICROBAN®

After you clean everything real good with TSP, you might be able to soften the old caulk with mineral spirits. Whatever you use, get some good ventilation! All the stuff has fumes that used is a small area can keel you over.

Good luck

Celiner actually needs to answer Tom's question before we can do much more. If this is a fiberglass stll Dap is the way to go. If however it's a combination fiberglass pan and ceramic wall she'll need stainproof grout for the walls.

It depends if you have silicon based or latex based caulk. Silicone sometimes just peels off. Find a loose end and pull on it. Latex based caulk hardens and has to be carefully scraped off.

Chances are that the black "stuff" on your caulk is fungus or accumulated residue from soap and shampoo. Today, you can purchase caulks that prevents growth of fungus.

Latex caulks are easier to apply for homeowner since they can be cleaned with water. Silicon requires some practice before you get nice bead.

To re-apply caulk: first make sure the surface is clean, and dry. Best is not to use that particular shower for couple of days.

With silicone, we always apply denaturated alcohol from spray bottle first to fine-clean the surface. (Home Depot: Paint section ). Wipe it off with paper towel. Cut off 1/8" section of tip form your tube of caulk. Than carefully and at slow pace, follow the area to be caulked. When finished, I spray the newly applied bead with alcohol again and gently go over it with my finger creating coving along side of the edge. Remember, with silicone, you can try to smooth it only once, maybe twice. Third time you go over it, caulk will wrinkle or you will strip it. Then it takes lots of effort to clean it and reapply. But whatever you do, stay as far as possible from water as you can.

With latex based caulk you can go over newly applied bead with wet fingertip. You have few minutes before it sets and starts developing wrinkles under you finger.

Some installers tape along side the caulked area blue masking tape to prevent caulk from spreading too wide. When smooth and still wet, they peal it off.

In both applications, it is important that you allow for proper cure time. With silicone it is about 72 hours. If it cures properly - it will last for very long time.

Practice someplace else first before you do it in your beautiful shower... and... Good luck !

Hi all. Thank you all so much for quick replies. Have not had access to internet for some time but am now back in action. You are correct, I did not give enough info in my question. Not up on the plumbing terms so I will do my best. My remodeled bathroom is approx 4-5 years old. The sealant is between the base and the door of the showerunit. It is a manufactured unit. I think the frame is made from pvc and glass. I don't think it is fibreglass (maybe the base is made from fibreglass?). The doors are very heavy to close. They are sliding doors. The glass doors have a special coating on them to prevent soap scum and boy does it work. It was an expensive unit. I had to import it direct form the UK. Sorry I can't be any clearer on that. The sealant is white silicon. All of the sealant has turned black except for a couple of cms here and there. The problem is worse in the corners. The water supply is city water. The water has a lot of lime in it. Only one wall has tiling. The tile grouting is perfect after 4 years. I don't know what caulk is. I live in Ireland so I will have to find out the ingredients of the products you recommend and get equivalent brand here.

Once again thank you for the replies. Very much appreciated.

I am not 100% sure but I think DAP Products - Caulks and Sealants - DAP® KWIK SEAL PLUS® Premium Kitchen & Bath Adhesive Caulk w/MICROBAN® is available in your country.

I think I would try a little clorine bleach first, sounds like mold and mildew..