Return to the Stained Glass & Mosaics Forum | Post a Follow-Up

black grout going white, why?

Posted by iminmystudio (My Page) on
Sat, Jan 31, 09 at 16:09

Hello from Sydney Australia!
I just found this forum last night and I've read heaps of post and looked at lots of photos, wow some beautiful work.

I've been making and selling stained glass art for a few years now and love it with a passion but I need help. I really want to make big mosiac water bowls for outside to float candles or flowers in, my problem is that I love black grout and whenever I fill a black grouted bowl with water and leave it for any length of time the grout seems to bleed white powder almost like salt, even with glass on glass applications so it's not the surface.

The latest grout I used is called Mapie ultra colour and is made specifically for swimming pools and it still does it, I have talked to lots of experts/trades men and they say it must be the glue I use(silicon), so I did a test bowl not gluing anything on it, I just smeared the grout around the bowl let dry way over the recommended time, filled it with water and it still went white.
The guys at the tile shop are great and told me to bring it in and they will follow it up with the rep. But I thought you guys might have an idea while I wait for answers?
I did try searching but couldn't find anything.
Cheers Deb

Follow-Up Postings:

RE: black grout going white, why?

Hi Deb! I've never heard of that before. I just did my dog with GOG and used black grout, actually same brand you have Mapie and it has not turned white at all. I've even sealed it after with Tile lab sealer and then I varnished it with a regular outdoor varnish and it's still black. Would it depend perhaps on how long you leave it with the water? I only add a few drops of water at a time until it gets to a creamy consistency and then I use it. If you do find out why, let us know for sure. Good Luck!

RE: black grout going white, why?

i'm not sure if this will help but could it be that the water you're using to mix your grout has a lot of minerals in it? same thing for the water you're filling your finished bowls with? i'm wondering if what you're seeing isn't grout at all, but minerals that have settled (which would show up a lot against black grout.)

i'd try mixing the grout powder with filtered or bottled water, in case that's the problem. maybe try filling a finished bowl with that, too, just to see.

the water in our last city was extremely hard and my black grout would turn light gray upon drying. once i switched to filtered water, my grout stayed dark.

RE: black grout going white, why?

I agree with Joy, I think its minerals in the water... can you buy some distilled water?

RE: black grout going white, why?

check this company out. They make a grout stain in hundreds of colors . It casn be used to recolor any grout. They have a good technical department you can call.

RE: black grout going white, why?

thanks for the replies, I will try distilled water in a small bowl, but if that is the only solution it won't be sustainable as the bowls I am talking about hold roughly 60 litres of water, I really need to just fill them up with the hose.
Thanks for the web site I had a quick look lots of interesting products.
I might just have to use grey grout:(
Thanks again Deb.

RE: black grout going white, why?

You shouldn't have to fill it with distilled water, just make your grout with it

RE: black grout going white, why?

This might help. I use the Mapei brand also, but when I grout outside things, I use the mortar for grout. You can color it w/pigment or Tints All.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Stained Glass & Mosaics Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here