Since some parts of the siliconed area of my bath tub are damaged, I need to replace the silicone. Is there an easy method to remove that silicone?
I use a plastic putty knife. Some of my guys even use plastic knives (yes the kind you use at bar-b-ques).
The whole purpose is to scrape it off without damaging what is underneath. The plastic knives add a serrated cutting tool and the shape is better for cracks/smaller areas.
Some things life (others) has taught me:
- WD-40 helps for some reason. If I give the area a quick spray, wait 10 mins, it cleans up easy 80-90% of the time. No idea the science behind this.
- Razors/metal knives aren't worth it. Yes they are faster. But all it takes is one chip and that ends up taking longer to repair than the total removal of the caulk. I have learned my lesson 5-6 times.
- Hair dryer is a mixed bag too. Unless you are 110% sure it is silicone, I wouldn't be aiming a hair dryer at it as it may make your mess bigger.
- On tough jobs I go back to my fix for 90% of cleanup. Bucket of steaming hot water, Dawn, and bleach. Sponge some of the hot water to the problem area - I use a kitchen pad which is a sponge on one side and a mild scrubber on the other. Wait about 30 seconds and repeat until caulk residue is broken down enough to remove with a light scrub.
To remove the last traces ready for the new layer, a product is available. It's called "silicone eater" or "silicone remover" here in the UK, and is sold with the sealants wherever there's a good selection of them.
You really do need to get most of it off mechanically first, and it's always worth seeing if it just peels once you've made a start - sometimes it isn't very well stuck. Angled scrapers are sold in the same place, made of plastic with a fairly sharp edge.
"Easy" is relative. A hair drier, razor blade scraper, needle nose pliers, patience and care.
I use a box cutter to cut it out myself. I've had good success with it, but be careful if you have a fiberglass tub.
Mineral spirits (e.g. paint thinner) will soften silicone caulk, use that with your scraping tools as mentioned in DMoore's answer. I will follow up with a wipe with acetone or alcohol to clean any residue before reapplying.
Putty knife (spade) and 8 in one tool works well. If you are looking for a solvent try Zep degreasers. They also have industrial strength removers and for a great price. Silicone is made to withstand moisture. On occasion I even cut my cleaning products with isopropyl alcohol.
Patience, elbow grease and a few tools worked for me to remove silicone from a glass door insert for a tub. I used a plastic scraper (pictured) for the initial few passes. A razor blade scraper (pictured) for detail silicone removal and the silicone solvent (pictured) for final passes. This may seem like overkill but results were great and no tub damage.