I'm having trouble sealing the grout on my bathtub/shower wall. The tiles about about a foot square synthetic with 1/4 inch lines of grout. We sealed them when we moved in about 7 years ago with no problem. The grout began showing signs that water was getting in (i.e. it got dark when we took a shower) in an area about 4 tiles high on the side and 3 under the showerhead about 6 months ago.
I first tried to seal it again about 2 months ago using the cheap stuff that came in a bottle with a brush applicator. After putting 4 coats on over a week or so, the sealant was still just going right into the grout whenever I put it on. My wife got tired of not using our shower so I gave up and water just seemed to soak right in.
I bought 511 Impregnator a couple of weeks ago thinking that maybe I needed something stronger. I have put 3 solid coats on with a sponge brush using a third to half of the bottle. There has been some improvement, but grout is still not sealed in the majority of the area (i.e. the sealant just soaks right in turning it dark).
Any tips on why the sealant isn't sealing? Or any tips on a better way to apply it? I try my best to catch it with the sponge as it runs down the wall and brush it back up or into the grout. I am following the instructions re: waiting 48-72 hours for it to dry between coats etc.
One thought I had is that we previously used a bleach cleaner to clean the tub and grout. Our water turns the grout orange after is allowed to seep in for a while, so we used the bleach cleaner to get rid of the color. Before I started sealing with the 511 Impregnator I also used as special grout cleaner, hoping to flush out any bleach that might be in there still. Could that be the problem - bleach built up in the grout breaking down the sealant as I apply it?
My wife wants her shower back.