laquer thinner on shower grout joints

[KKlaw]

Hi everybody,

Per one of your tile expert's advice, I used Ceramaseal grout stain (solvent based) to stain the grout joints in my shower because he said that it would allow better breathability for the grout joints since the grout joints are in a shower. I was doing the staining over the weekend. I used a plastic spoon to scoop out some grout stain into another smaller container and then I left the plastic spoon in the smaller container with the smaller amount grout stain that I scooped out and used to stain the grout joints. By the time I finished, I noticed that part of the plastic spoon already dissolved or melt in the smaller container due to the solvent of the grout stain. The next day, concerned about the grout stain got contaminated by the unexpected dissolving spoon in the smaller container when I was staining, I decided to redo the staining. I started to use some laquer thinner to wet the grout joints and use a cotton cloth to scrub the grout joints. Most of the grout stain seems to be able to be emulsified by the
laquer thinner and rubbed off using a lot of elbow grease.

Since the laquer thinner is quite penetrating, I am wondering if the laquer thinner would somehow penetrate into behind the cement backing board and reacted and dissolved some of the tar-based water barrier behind the cement backing board nailed to the stubs. I also would like to know if I can still use the original can of grout stain that I dipped the plastic spoon two or three times (total for about two seconds) when I was scooping out grout stain. If I clean the grout joints enough and make them look dark in color after wetting with water, does it mean that it is ready to accept grout stain or sealer.

Many thanks. K.K. Law

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[doitright]

Hi KK :)

I would have no concern of continuing use of the grout stain. Your water TEST for darkening is sufficient.

As far as the lacquer thinner dissolving the membrane over the cement board, I don't think it should be a concern (unless you were soaking the horizontal grout joints).

What membrane did you use? :shades:

[KKlaw]

Hi John,

The contractor used tar paper as moisture barrier behind the cement backing board. I was not soaking the grout joints. I was using just enough lacquer thinner to re-emulsify the grout stain so that I can rub it off the grout joints.

I have a separate question and I would appreciate it greatly if you can share some expert advice. Yesterday I also saw a couple of grout joints right next to the shower glass panel frame that were not strong enough to withstand finger nail scratching. Upon further inspection, they started to get loose when I used a screwdriver to push into it a little bit. Since the crumbling grout joints are for a couple of the tiles that are now underneath the shower door panel frame, I was thinking of having the shower door guy to lift up the frame, and then regrout and re-install the frame. I called up the shower door guy who installed the shower door for me and he said that removing the shower panel frame may damage the shower door installation and might cause a leak. He suggested that I could regrout the grout joints all the way to the frame and the reapply silicone caulking between the frame and grout joints. He said that would do it and would not leak.

Please let me know what is the best way to solve this problem, and whether his proposed solution makes sense.

Thanks,
KK

[Davestone]

If the tiles aren't loose i would do like he says,and be sure to not use premix grout.

[KKlaw]

Hi Davestone,

Please see attached picture that depicts the tiles underneath the shower frame situation. The area circled by the green circle are the two tiles that need to be regrouted. The areas that are pointed by the red arrows are the grout joint areas in which the loose grout was removed. The loose grout was removed up to the frame area and the old grout at the grout joints underneath the frame was not removed since it is difficult to remove the old grout underneath the frame and also difficult to repack new grout underneath the frame. So as discussed, the plan is to regrout the grout joints up to the the grout joints up to the areas underneath the frame and reseal the frame and the tile/grout intersection with silicone caulking.

I would appreciate it very much if you think this is a good plan to do the leak-proof repair.

Thanks,
K.K. Law

[david bassler]

KKlaw

Solvents will dissolve the colorant as you know now. Also you don't want to scrub the colored grout for at least a month.

For the missing grout; you can get a color matching caulk from most tile stores. Just tell them the manufacturer and color and they can order it.

[KKlaw]

Hi gentlemen,

This grout coloring job is taking longer it takes and my wife is getting very impatient about it.

I have one more question. As I have reported last time, I was trying to remove the grout stain I applied last time when I accidentally left a black plastic spoon inside the small container which contained the amount of grout stain I was using to color the grout joints . The plastic spoon slowly dissolved in the solvent based grout stain resulting in darker grout stain color. I have tried to my best effort to use lacquer thinner to emulsify the colored joints and use cotton cloths to rub the grout joints to remove the incorrectly colored grout joints. The question I have is whether I need to remove 100% of the old grout stain before I can reapply the grout stain. Some of the grout joints do get dark when I wet them with water. However, when I wait for the grout joints to dry and try to clean them with lacquer thinner and cotton cloths, I could still see some small amount (not as much as when I first cleaned them) of the old grout stain gets rubbed off on the cotton cloths. Do you think I have to clean them some more before I can reapply the new grout stain or I can go ahead and reapply and the grout stain will penetrate and adhere to the grout joints well? Also when I rub the grout joints using cotton to rub the grout joints, a minute amount of very small particles get rubbed off. I think the small particles contain the cotton cloth particles that get removed and a pretty small amount of grout or sand particles get rubbed off. I hope the grout joints are still structurally sound.

Please share with me your expert advice on this situation.

Many thanks again,

K.K. Law

[doitright]

Hi KK :)

You never mentioned that it was a black spoon! :bang:

Which solvent based grout colorant did you use? My instinct tells me that you should be able to reapply the new grout stain and not have any issues. I always recommend to do a TEST area first.

If you are in doubt, call the manufactures technical assistance.

[KKlaw]

Hi John,

The grout I used was Ceramaseal solvent based grout stain. Are you saying that even though I may not have removed completely the older grout stain, I can apply on the grout joints without any problem, if I test it out first?

Thanks,
KK

[doitright]

Hi KK :)

Sorry, I forgot you mentioned Ceramaseal. Here's a link to the Ceramaseal Grout Stain Data Sheet (http://www.bostik-us.com/TDS/TDSFiles/Grout_Stain.pdf) .

Notice it says to thoroughly dry between coats.

TEST first, and you should be good to go! :tup2: