STAR BRITEUltimate Fiberglass Stain Remover - Easy-to-Use Marine Grade Solution to Eliminate Tough Rust, Leaf & Waterline Stains for Boats and More - Maximum Cleaning Power Gel Spray

After reading so many reviews—some saying it works great, others saying it does nothing—I purchased it, then let it sit unopened for months as my fiberglass shower floor got dingier and cruddier until I couldn't stand it anymore. So I sprayed the stuff on the floor and sides of my shower and decided to leave it for 20 min, then check back. (Directions for the 16 oz and 32 oz differ for some reason; I agree with the 32 oz directions, as that is what worked for me.)When I checked, nothing had changed, so I scrubbed a little with the soft side of a blue sponge (w/nylon scrub on the other side), but nothing came off, so I left it for another half hour. Meantime, I reread the reviews. Turns out, I found more critical reviews than I remembered, so I got discouraged and thought I'd wasted $10. But still, after the half hour was up, I rechecked the shower and scrubbed a small area...and something magical happened. The stains/grime came off easily in that area, but in others, even heavy scrubbing (again, with the soft side of the sponge since you're not supposed to use abrasives on fiberglass) did nothing to lift the stains off.So I was encouraged by that one small area, which wasn't as dark and grimy as the rest, and wondered what would happen if I sprayed heavily and just let it sit for a long time. So I let it sit for about 90 min. Then when I scrubbed, more seemed to come off, so I was like, okay, I'll spray again and let it sit for another couple hours, which took me to 8pm. When I pulled back the curtain, I couldn't believe what I saw...I turned on the shower and without even using a sponge, most of the stains and grime had disappeared! I watched as the water rinsed away the product, and the floor was so much smoother and cleaner than it had been in years.It's not yet stain-free, but I cannot believe how much better it looks!! I just sprayed it again and will let it sit overnight and see what happens. I don't even know if using a sponge was necessary. It seemed to help bring up some grime, but I think just letting it sit was the key. I mean, you be the judge...these two preliminary photos show the results after spraying and leaving it for several hours, with a minimum of scrubbing. And actually, the first photo was after I had sprayed and let it sit for a half hour, then scrubbed a little. But the major stains are still evident.I'll add more photos as I progress. I just cannot believe how well this works, and just wonder if the bad reviews are because people aren't leaving it for long enough. The bottle says a few min, not a few hours. Good idea to test a small portion (I didn't because I'm impatient) to make sure it does no harm. But OMG. I'll be getting the 32 oz bottle now because I'm already running low on the 16 oz one.Last tip: Ventilate your area. I should've used a fan, but I was obsessed with my shower and forgot.Update a day later: With more sprays left on for several hours, it looks even better. I'm having trouble with vertical surfaces because the liquid dribbles down in thin lines, so I need to remedy that. Bottom line, where the liquid sits, it does the job.

It works fine!!! The before and after tells the story…only took 10-15mins. Sprayed it on let it sit, rinsed and wiped clean with sponge.

I tried this because nothing else has worked to get my 33 year old fiberglass tub and shower looking better. It has a lot of hard-water stains and yellowing from over 3 decades of use. I was hoping that this would at least do something, but to no avail. I followed the directions and even left it on longer than it recommended. I did not notice any change what so ever! So, save your money and research other methods, because this DOES NOT WORK! I don’t own a boat, so I can’t say whether it works for the intended use. But it certainly didn’t work for my tub. A complete waste of money!

Cleaned nicely. Cleaned and repeated. All stains not gone but looks much better! Worth the purchase.

Like the title says I wanted to and I should have! I was rushing to move and get everything cleaned to better than we found it. I had no idea or shower and tub were as bad as they were until I used this product! I was blown away by just how good of a job this did for cleaning what I didn't even know was there. I had no idea that a fiberglass insert could basically sparkle and shine, until after this. It worked phenomenally. The spray mechanism was easy to use where it didn't affect my wrists too much but also didnt seem flimsy or like it'd break in my hand while squeezing like cheap bottles. It did take a couple of applications and some elbow grease to be really beneficial. I did spend some time scrubbing. So it wasn't as easy as spray, wipe, and rinse for me. But like I said, there was more than I realized... It got the majority of stains, rust and calcium buildup, soap scum, and made the whole tub and shower the same color. I thought I'd use it and just toss what was left, but it was so great I kept it and will be using it in our new tub and showers. Great value for the money spent.Please please do your best to keep the area you spray it in properly ventilated as much as possible though. It definitely has a strong odor. We only had a fan to help so it was much more in the air. I'd suggest using gloves as well. I didn't the final clean and didn't have any issues but it's still a precaution to take if you have sensitive skin. With or without gloves wash your hands after use though. I will buy more when I need it again! A quarter of a bottle went a long way.

Good product. Did help more than others.

Use it for my fiberglass surround tub. Didn’t do a good job on far as goes to top stains. It did lift up some of the mineral stains that was on the shower wall, but it didn’t work for the top stain that was in the tub

Product works great. I had a brown stain in the shower from a leak that nothing I tried removed. Two applications and the stain is gone. Highly recommend,