I had a bathroom remodel last year. The contractor put in a Kohler Acrylic tub and Meganite walls which are also acrylic. The contractor sealed the walls and the walls to the tub with a silicone caulk. Within a couple of months the seams leaked and water seeped onto the tile floor. I removed all of the silicone caulk and used a regular bathroom "white" caulk. It apparently did not adhere to the wall/tub joint and I just removed all of it because mildew started to form. There must be a caulk that joins acrylic and acrylic to make a water tight seal. I would love to know what to use. Thanks!!

You should be able to use a water resistant silicone caulk.(for bathrooms and such). The important part is to make sure all areas to be caulked are clean and extremely dry. Then you need to let it set for AT LEAST 24 hours before using shower. IF the silicone you buy says it is usable on shower or tub fixtures, then all you need to do is clean and dry the surface that requires caulking.

MGD77 is giving you excellent advice... I will probably repeat some of his points in my response...

It takes some time to learn how to work with silicone caulk. As MGD77 says, it is imperative that surface you dealing with is CLEAN and DRY. Also, no moisture in the bathroom ( don't use shower couple of days before application and at least 3 days after application ).

Here is the proper way of applying silicone caulk:

1. Go to Home Depot and purchase small container of DENATURATED ALCOHOL ( D.A.) and spray bottle. Pour entire container of D.A. into the spray bottle.
2. Prepare tube of caulk. Use 100% silicone, like GE - 50 year silicone. Don't be stingy: buy the best one. Cut off about 3/16" from the tip under 45 degree angle. Put tube into caulking gun. Have clean terry towels ready to be used.
3. (assuming entire area is CLEAN and DRY and NO MOISTURE is present): Take spray bottle with D.A. and spray it over the entire edge you want to caulk. Take terry cloth towel and immediately wipe it off.
4. Take tube with caulking and apply bead of caulk in one, continuous motion from top to the bottom. Push on the trigger so the gun dispenses as much as is needed - but it is better to apply bit more rather than less. Pay attention to how much you are dispensing. Caulk should enter cavity area and small bead should stay on top. If you want clean job, you should not reapply second bead over first one. So pay close attention to it ...
5. Immediately, take spray bottle with D.A. and gently spray the entire bead of caulk with D.A.
6. Put your finger on top of the run and gently smooth new caulk with One Slow Continuous Motion, leaving finger-cove behind. Look at the bead you are leaving behind your finger. Push more or less as needed. You can go over it one more time, but quickly. Once D.A. evaporates, you will damage new caulk and job will look sloppy. Keep cleaning your fingers with terry cloth towel. Make sure tip of your finger is wet with D.A. every time you touch the caulk. Never touch caulk with dry or (water) wet, or dirty finger. Do not go over newly applied caulk with the dry towel. Soak one corner of the towel in D.A. and gently wipe off unwanted caulk from along sides of the bead. Stay about 1/16" away from the actual bead.
7. Repeat same application all around the tub
8. ALLOW TO CURE FOR AT LEAST 72 HOURS OR MORE. The longer, the better. If you have shower in the same bathroom - than do not use it until caulk cures.

Presence of wetness, dirt, or high % of moisture in the bathroom will make new caulk not to adhere as expected and eventually, it will peal off. Do not apply caulk on, or around, rainy days...

Some workers prefer to carefully apply masking tape along the edge where caulk will be applied. This way, the leftover caulk will stay on the tape which is then pealed off with the caulk on top of it. But this requires some practice before hand...

Also, nowadays, you can purchase "caulking triangle" - a device used for smoothing beads of caulking instead of using finger. It costs couple of dollars and leaves nice, smooth, coving...

If applied and cured properly, caulking will seal - and look good - for decades.

Good luck caulking... Let us know how you did... Milo

Silicone caulking is not the best material for acrylic materials as it does not adhere well. It will peel right off in fact, and I've had this experience recently when our contractor used silicone for kitchens & baths on our acrylic tub. The best material to adhere to acrylic is a latex based caulking, such as Mono Ultra Kitchen & Bath. For any caulking used always determine what the manufacturers ratings are for adhesion to the materials you are working with.

Silicone of any kind does not work. I have some to give away if ayone wants to try it on their acrylic tub and enclosure. The only bonding caulk is called.. LEXEL and is made by Sashco... 5 ounce tubes and also comes in the standard size for caulking guns. It's pricey and as far as I know, comes in white and clear. It's also quite stiff so requires a strong and steady hand to apply evenly.