Help, quick! [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile

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zel
08-26-2001, 02:48 PM
I'm in the second day of tiling and I think I mixed my FlexBond super-duper modified thinset too wet. Yesterday I was convinced it was too dry--it was very hard to work with. Today I added a little more water. It sure is easier to spread and move the tile around in, but I pulled one up and not much was sticking to the tile. Am I screwed? Should I let it sit for awhile? Should I take the loss and hope the ones I've already laid--about 25 tiles--don't pop? I'm cutting it extremely close on tiles, so I can't afford to replace any.
I'm getting the tile into the mortar well. I hope someone will tell me that the bond will happen.

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zel
08-26-2001, 03:07 PM
By the way, this is my tile over cutback project that John told me to "go for". John, I know you're out there--I can hear your keyboard.

LDavis
08-26-2001, 03:08 PM
Zel, does the Flexbond (good stuff) hold a ridge at all when you spread it with the notched side of the trowel?

If your not getting transfer to the tile back, sounds like its probably real runny! Let what you've done set overnight, then see if you can pull a tile up in the morning. Like I said, Flexbond is some good stuff, you may be surprised. Just make sure you mix the next batch so the spread ridges stand-up after spreading.

Rob Z
08-26-2001, 03:11 PM
Hi Zel

If it is not on the tile when you pull it up now, it's not going to start getting on it while it cures.

Trying to tell someone how to mix thinset and grout is a bit daunting. Best thing you could do is buy one of Michael Byrne's videos and see it "in person".

As for the ones that are down, I would say that if you are seeing the results like you are seeing on the other tiles, it's probably like that under those 25 tiles that are set.

zel
08-26-2001, 03:12 PM
It seems to be holding a ridge pretty well. Probably not as square as yesterday. Can I salvage the rest of the mortar, or am I done for the day? You know, that's some expensive stuff.
If I can't pull it up tomorrow, is that a real test? What happens when it gets some traffic?

Rob Z
08-26-2001, 03:19 PM
Hi Zel


This is kinda like trying to coach somebody with their golf swing over the phone. Without being there, it's hard to know what the problem is.

What size trowel are you using? How flat is the floor? Size of the tile?

Describe your troweling technique and how you are setting each tile. That may help.

Once that stuff has been mixed and the hydration reaction has started, adding more material or liquid to adjust the mix is a no-no.

LDavis
08-26-2001, 03:24 PM
If the thinset is "holding a pretty good" ridge I don't understand the lack of transfer to the tile back. Are these flat backed tiles? Is the floor level. How large and how thick are these tiles and what size notch are you spreading with? If you can still pull the ones already set, you can take them outside and wash the thinset off and salvage the tiles. Flexbond has a great "pot-life". How long has this batch been mixed? If not long, you may be able to add more powder and get a stiffer mix. If its been awhile, your probably better off wasting this batch.

LDavis
08-26-2001, 03:26 PM
Looks like I'm driving in Rob's dust, I'll let you guys have it.

Rob Z
08-26-2001, 03:28 PM
Latney

Pull alongside, friend. I can handle the traffic.

Rob

LDavis
08-26-2001, 03:31 PM
Rob, looks like we were thinking and typing the same thing at very near the same time.

zel
08-26-2001, 03:31 PM
12-inch tiles.
The floor is relatively flat, but there are some low spots.
1/4 x 3/8 trowel (I was wondering about that, but that's what the guy at the store gave me.)
I'm troweling in swirls. The mortar is getting pretty well flattened, so I know I'm making contact. Yesterday I couldn't hardly move the tiles--I broke a couple in the first ten minutes trying to pry them up to take a look. I was sore as hell today from trying to get them pushed into the mortar. I remember one of you guys saying that modified thinset is harder to spread.

Rob Z
08-26-2001, 03:34 PM
Allright Latney, here's a test. what am I thinking about right now.

(Hint: it is after 5 o'clock, isn't it?)

LDavis
08-26-2001, 03:36 PM
Trowel size sounds good. With a 12" tile, lose the swirls and comb the thinset out in one direction. (ridges parallel to each other)

Rob Z
08-26-2001, 03:37 PM
Zel

The swirls are a problem. Trowel the material in straight lines, and set the tile in and push a 1/4 " or so at right angles to the thinset ridges.


You may need a 1/4" x 1/2" notch trowel to get good coverage.

It shouldn't be that hard to trowel the stuff. I think it may be too stiff.

zel
08-26-2001, 03:38 PM
In answering your question, L, I can't pry today's first ones up. At least without breaking my fingers or the tile. I think this adds up to chucking the rest of this batch and hoping that these hold. Unfortunately, they are in the area with the highest traffic.
What are the chances that if they decide to pop, they will not be damaged and I can reuse them. How long might that be? I know these are impossible questions to answer, but I am looking comfort.
Should FlexBond be very thick and difficult to work with as it was yesterday? It didn't seem like I added much more water today, but then again, 5 quarts for 50 lbs ain't much to start with.
What's another $17 (the cost of half a bag)?

LDavis
08-26-2001, 03:39 PM
Rob, I'm having one too. Only the first though. Its not quite 5 here!

Rob Z
08-26-2001, 03:43 PM
Well, as grandpa always said..."It's five o'clock somewhere".

Zel, hard to say about the reuse of tile. Buy that video, unless you have someone to show what the consistency should be like. Those ratios on the bags don't always work, depending on temp, humidity, etc.

LDavis
08-26-2001, 03:47 PM
Zel, if your having that much trouble getting a tile back up now, I'm going to assume you've got enough coverage to do the job on those. With the Flexbond, I don't think I'd worry too much about these suddenly turning loose down the road. Try mixing less than the full 50lbs at a time. Gives you more flexibility getting the mix right. Once you add too much water to the full 50lbs, your stuck, or at least have to open another bag and try to fit too much thinset in an already full bucket trying to "stiffen" the mix.

Sounds like somewhere between your first mix and this mix lies the "right" mix. It shouldn't be so stiff that you can't spread it though.

zel
08-26-2001, 03:47 PM
So, are swirls only for small tiles? After I finished yesterday, I was convinced that I should be swirling. The cover of John's book is what put it in my head.
If you think that swirling is the problem and it seems like it's holding a ridge, should I continue and go straight (troweling, that is)? It was moving a lot quicker today.

Rob Z
08-26-2001, 03:51 PM
Zel

Recent experiments by the National Tile Contractors Association proved that the straight combing technique is superior to the swirling technique.

This happened after john published his book, I think.

Swirling is now best left to getting the two flavor mix at Dairy Queen.

LDavis
08-26-2001, 03:57 PM
OK, now I see the problem, You read John's book!!!

Just kidding John, I've got a copy myself.

zel
08-26-2001, 04:01 PM
I'm not going to risk anymore. Hopefully my effort to "go bulletproof", as John called it, and use FlexBond instead of the regular old modified will pay off on these. I will just suck it up the rest of the way and stay closer to the directions. I'm probably worrying too much, but I'd rather waste $17 than spend the next year worrying. If I can find some tile suitably constrasting and inexpensive enough, I may go back to a design I was considering in order to free up some tiles in case I do lose some.

zel
08-26-2001, 04:04 PM
Actually, I just saw the cover on this site. Damn you, John.
If you pros work as hard as I did yesterday, you really earn your money. In the first ten minutes, I broke two tiles and smashed my thumb (I gave up on trying to beat them in). I am sore as hell today, and I was dreading doing it today.

Rob Z
08-26-2001, 04:07 PM
Zel

Most of us are doing this kind of work to avoid getting real jobs in offices where we have to wear suits, go to meetings, interact with coworkers, answer the phone,write reports, sit at a computer all day, (what am I forgetting).

Keep on trucking...it gets easier.

LDavis
08-26-2001, 04:17 PM
Shave everyday, bath everyday, brush teeth everyday, waste time in airports, hotels, rental cars, brown-nose the new district/regional manager, play the "bouncing bonus" game, etc., etc.,,,........

Yeah alright, so I still do MOST of the personal hygiene everyday....sure don't miss the rest of it.

zel
08-26-2001, 04:37 PM
Well, I just went down and set one more tile, using the straight method. It stuck better, but still not like the pictures look. There were lots of lines. Should I go with a different trowel? The tiles that I broke yesterday and then pryed up still did not have the 80% coverage.

Rob Z
08-26-2001, 04:45 PM
Zel

Use a larger trowel (a 1/4" x 1/2"). Try http://www.contractorsdirect.com if you don't have a good supplier in your area.

Rob

zel
08-26-2001, 04:54 PM
Ugh. I hate home improvement.
You have to heap the mortar on with a 1/2 trowel, huh? There's another bag ...

Rob Z
08-26-2001, 05:01 PM
Zel

You will use more mortar with a larger notch trowel.

Switch to 2"x2"'s if you want to save on thinset .

kalford
08-26-2001, 06:18 PM
Zel,
Combing the thinset in straight lines allows air to escape.Sometimes when you press a tile down into the thinset you can hear it.Sounds like those plastic bubble wrap things that the kids love to pop.

Allowing the air to escape keeps pockets from being trapped which would result in less coverage and a weaker bond.I use a 3/8" trowel most of the time and it usually provides plenty of coverage.Make sure you are pressing down and twisting at the same time.This is what "sets" the tile.

Bud Cline
08-26-2001, 09:26 PM
Two questions, then I'm out of this one.


1.) Your not mixing the full 50# at one time are you?

2.) The last few tiles you pulled to check your coverage, can you estimate the percentage of thinset coverage?

zel
08-27-2001, 07:19 AM
Yes, I mixed all 50#. The bag said it would keep 4-5 hours in the bucket.
The one I looked at just before I started this thread had hardly any sticking to the tile. The ridges were flattened out, but it was not sticking. I did one more after that, combing straight, and it stuck to the tile. But I don't think it was close to the 80%. You could see the separate lines for the most part--maybe 50% coverage.
I said before that the ridges were standing up, but I don't think they were as wide as they should be--I think it was too wet.
I went down there this morning and tugged a bit on a couple of them--including the last ones--and they seem to be holding. But, of course, who knows once they get traffic.

Bud Cline
08-27-2001, 09:49 AM
Flattened ridges not sticking to the tile would be an indication that the tile is not being placed soon enough after the thinset is spread. When the thinset is combed out obviously it begins to dry in the air, in addition your substrate will begin to wick-away moisture in the mix. You may be getting ahead of yourself in spreading too much thinset at one time.

The pot life is as you state, but, chemical reactions are taking place only to a point in time, then the curing/drying process begins. Someone smarter and more scientific than I would need to explain all that. I wouldn't mix too far ahead to insure fresh batches as the job progresses.

When combing the thinset, the thinset should stand in place as formed by the trowel and not sag before the tile is placed. The other side of that coin is if the thiset is too stiff it will not compress properly and thereby cause tiles to "stand proud" of what they otherwise would.

Thinset not sticking to tiles can not only be from drying thinset, but also from tiles that have powder (talc) on them. Also a wet tile may not pickup the thinset.

If you are not experiencing at least 80% then I would expect trouble down the road.

zel
08-27-2001, 11:02 AM
Thanks, Bud. Lots of interesting info. The powder thing is intriguing. I don't think that spreading too much at once is a big problem for me--I have been doing them three at a time. Although on the last few I did a 3x3 square at once. I may try half batches of mortar. The thing I'm afraid of there is knowing how it should be mixed. At least with a full bag I can go basically by the instructions. With a "half" bag it may be difficult for me to get the ratio correct. Maybe I'll use my bathroom scale ...

kalford
08-27-2001, 11:11 AM
Zel,
I never mix more than half a bag at a time.It should have the consistency of oatmeal.

Bud Cline
08-27-2001, 12:12 PM
I must confess I would have to read the directions to know the proper mix ratio. I have done it by "feel" for so long it's easy to get a proper mix every time. About a half bag is as much as I ever do unless we're plowing across an open field. The last big one I did was 5000 feet of open ground and with two spreaders and two setters we only mixed two full bags at one time.

zel
08-27-2001, 12:35 PM
Would that be microwave oatmeal or the stuff out of the cylindrical cardboard? With milk and sugar? ;^}

kalford
08-27-2001, 02:40 PM
Zel,
Thats the old cylinder box mixed in hot water off the stove.I always add sugar to mine....or maybe cinamon.Stir slowly using a table-spoon so as not to get too much air in it........hey...I'm serious.Stirring too fast makes it "fluffy"...yuk!

zel
08-27-2001, 02:51 PM
So, you wouldn't use a paint mixer and a drill?

Bud Cline
08-27-2001, 03:00 PM
They also make a small Jiffler suitable for mixing batches of oatmeal.

I'm sorry Art! No don't! Ouch! Ouch!
Ah dammit Art!!!

LDavis
08-27-2001, 06:56 PM
Zel,

If your looking for a "general" water to powder ratio, I'll give you a tip I used with a new helper I have so he could "get in the ballpark" with a batch of thinset. Are you a coffee drinker? If so, take/get a standard coffee can (holds 12oz of ground coffee, I think). A full 50lb bag of thinset will require between 5 1/2 - 7 coffee cans of water (modified thinset), depending on weather conditions. If you want to mix about half the bag, use the coffee can to add 2 1/2 - 3 cans water to an empty bucket.
Then add a little less than half the bag of thinset to the water in the bucket, while mixing.

This should get you in the "target" mix zone with only minor additions of water/thinset.

Works well for grout mixing as well. A 25lb bag of Custom's sanded polyblend requires between 2 - 3 cans, again depending on weather, tile, etc. Hope this helps.