Some SBC questions

[Tscarborough]

Re: Some SBC questions

The La Habra is formulated for a 90# bag of material, aggregate included, so if you are using just the color packs in SBC, adjust accordingly. If they are 50# SBC, for example, 1 color pack to 2 bags SBC is probably close enough.

Also note which base the color pack calls for, base 100 is white, base 200 is grayer.

[Dino_Pizza]

Re: Some SBC questions

Thanks, both you guys for the helpful info. And Keith, thanks for the lesson on hue and saturation. I'm on the right track with buying the white SBC.

I'm going to buy the "la habra stucco color" powders that Lowes and HD carry for pigments. The color cards displayed are numerous however they are all very light, very soft in color (saturation) since most people go for a lighter-pastel look on their home (not to mention most people are afraid of color...that's another subject...).

So, I'll buy the color of the powder in the bags and go by trial and error to get my perfect mix. It's only for the back of my oven-haus and the interior of the wood storages that are visible. Painting the SBC is a last resort, but an option I'll try to avoid. Thanks, Dino

[Tscarborough]

Re: Some SBC questions

The important thing to do when using white whatever is to look at the pigment itself, NOT the color card, just to clarify further.

[kebwi]

Re: Some SBC questions

But just to be clear, since I went through this when I bought the pigment, the color cards are not only for gray cement, they are for ordinary portland cement, or at best perhaps for conventional concrete mixes. SBC is different. In fact, all of these substances are different in their ratio of cement to total weight, usually in the range 10%-50% (I really don't know much about it).

The point is, the colors are prescribed by ratio of pigment to portland, not pigment to total, so if you really want to do it by the numbers (meaning with a calibrated color card), you have to know what fraction of your concrete/stucco/etc. is portland.

Basically, if you're coloring an unconventional substance (like white SBC as oppose to gray concrete), you may as wall just do it by trial and error anyway.

...but buy the desired HUE and to a significant extent the desired lightness. Just don't worry about saturation too much. Figure that one out the old fashioned way.

[Tscarborough]

Re: Some SBC questions

It is not the same for sure. Most of the pigments (if you use their color card) are formulated for grey, so if you use white, you will get either a totally different color (yellows-buffs) or an over saturated one (reds-blacks).

[kebwi]

Re: Some SBC questions

Worked like a charm. I dry mixed the powder and the SBC, thoroughly shook it in a bucket, then wet mixed it with pre-50/50 acrylic fortifier.

The only problem I had is that I massively overestimated my initial color mix. I kept adding more color in because I thought it looked really pale as a dry mix. Then I wet mixed it and it got REEEEEALLY dark. So then I desperately tried to dilute the dry mix by adding more SBC back in. Then I went TOOO dilute and the next wet batch was too pale!!! Third batch was Goldilocks though.

In the end, it worked great, but don't judge the color by the dry mix, it will look much more "powdery" and unsaturated than the wet product...and the final cured product will be somewhere in between the two. Try a few small patches in areas that you will add multiple layers to before you're done. Converge on the right color, then go for broke.

I'm not sure gray would look "dirtier", just darker. You could achieve the same effect by purchasing a darker tinted color powder in the first place. Bear in mind that lightness/darkness are not the same color dimension as saturation, so using gray vs. white SBC probably isn't the same thing as adding more of the same color to the SBC. Gray SBC will look darker, more color added to white SBC will look more saturated ("richer").

That's exactly why I preferred white, so I could most easily control the effects of the color by simply purchasing the required hue and lightness and mixing to the desired saturation.

[Dino_Pizza]

Re: Some SBC questions

Keith,
How did coloring the Quikwall SBC work out? I can only find the "white" sbc in my area (only OSH carries them, HD & Lowes special orders). I wanted to buy the 'gray' color then mix with brown pigment for my dirty concrete look but it's so easy for me to pick up the 'white' at OSH. Did you find the white was harder to get to the color you wanted or does it not matter, in your opinion?
Thx, Dino

[kebwi]

Re: Some SBC questions

Okay, sounds like regardless of whatever aesthetic issues I have, there is too much pigment in my current mix. I'll have to add SBC to bring back down to 10%, then make a test patch.

Thanks.

[Tscarborough]

Re: Some SBC questions

10% is a hard limit.

You can't tell what color it will be until you add water apply it and it dries for a couple of days. If you have it throughly dry mixed (very throughly), take a small amount, like a half a cup, mix it to the proper consistancy with a tiny amount of water, then smear it on a piece of plywood and let it dry in the sun and it will be preetty close to final color in ten minutes.

It is not important how much exactly you put in (for the bonding agent and the pigment(up to the limit)) the important thing is that you exactly the same in each batch as well the exact same amount of water. The best way to do it if you can't do the whole thing in one batch is to apply 2/3 of the batch, mix another one and combine them, rinse repeat. That will generally keep you on track.

[kebwi]

Re: Some SBC questions

Okay, I'm trying to color the SBC for the remaining coats. The first coat is complete, white SBC (it also comes in gray), acrylic fortifier, pretty thin in some spots. The second coat, and perhaps partial third coat (till I run out) will be colored.

I'm using iron oxide powder pigment, two brands that I bought separately and mixed together, they were very close already.

Now I'm trying to figure out how much powder to add to the SBC. I believe the prescription is somewhere between 5% and 10% oxide powder to portland by weight, regardless of the weight of the overall stucco material. In other words, a 50lb bag of SBC containing 18lb of portland (I called Quikrete, that's what the Quikwall SBC contains) should call for .9lbs to 1.8lbs of oxide (5%-10%).

Problem is, I dry-mixed a batch already and pushed it all the way to 2lbs (11.111%, 1/9th in effect) and it still looks rather desaturated. I daren't go any higher since I have already exceeded the 10% max. Since I haven't applied any of this SBC yet, I can easily (with some math) dilute it back down again by adding more SBC.

Also bear in mind that the acrylic fortifier, a liquid which is mixed into the water, is very milky white, so the color will become yet more faded when I liquify the SBC for application, because I won't be using just water, I'll be using 50/50 this milky acrylic fortifier.

Questions:

1. Is 10% a hard maximum? If I exceed that, even just to 11.1%, will that cause some sort of harm to the SBC? Will it not "stick" or cure or set or otherwise work properly? Do I really *need* to dilute my current 11% mix back to the prescribed range?
2. Why am I having problem? Why does it look more faded than I expect? Is it going to get really dark when I add water and trowel it on? It will clearly get darker when water is added, but that's just a visual illusion. It'll fade back again as it dries, right? So, should I expect it to "look better" after I mix and apply it, or will it remain as faded then as it looks now, dry in a pale, and if so, how does one ever achieve rich saturated stucco colors? I don't get it.

Thanks.

[ThisOldGarageNJ]

Re: Some SBC questions

I'm wondering if I can dilute it ahead of time and store it in a jug and then just mix that at the proper ratio for a given amount of SBC (1gal per 50lb)

Im not a scientist, But I dont see why you couldnt do that,,, I did it on the same day only because I was too close to being done.. and was too anxious... I used the liquid colorant too and had that premixed with the water...(we had that discussion the liquid colorant stinks) I am currently recoating a block wall with the sbc, and after adding the acrylic fortifier it seems to me like it actually spreads easier and finishes nicer..

cheers
Mark

[kebwi]

Re: Some SBC questions

I talked to Quikrete a bit. It's fairly straight-forward: between 1 and 1.5 gallons of water per 50lb bag of SBC. The high variance is only because SBC can be sprayed however, so they expected that 1 gallon would be right for trowel application. So, I just need .5 gallon water and .5 gallon acrylic fortifier per 50lb bag.

Now, given that I need to dilute the acrylic fortifier 50/50 I'm wondering if I can dilute it ahead of time and store it in a jug and then just mix that at the proper ratio for a given amount of SBC (1gal per 50lb) during a session...or must the acrylic fortifier only be diluted right when I mix the concrete and begin applying it? Does diluting it in advance ruin it somehow?

I also asked Quikrete this, haven't heard back yet.

Thanks.

[Tscarborough]

Re: Some SBC questions

If they give you a jar of fortifier per bag, then add the jar to approximately the amount of water they recommend, then slowly add to the dry mix. If you have a gallon of fortifier, it will tell you at which ratio to dilute, they are all different, but generally in the 1-1 range.

Also, just a general note for mixing any cementious materials. You should always add less water than you think it will take, thoroughly mix it for a few minutes, and then add small amounts of water until it is at the desired consistency. The nature of cement and aggregate is such that it will appear to be too dry until the cement and aggregate absorb free moisture, then it will "break", and become loose. It is at this point, right before it breaks when people add too much water, and it turns runny.

[kebwi]

Re: Some SBC questions

Forgive me Tscar but I'm going to ask you to clarify that. By mix the fortifier and the water, do you mean 1:1? When you say slowly add it, do you mean add the mixture or additional water only (I think you mean the mix)?

Thanks.

[Tscarborough]

Re: Some SBC questions

Mix the fortifier with the mix water. You should not use the amount of water they say, start with 1/2, and add slowly until it is at a workable stiffness, between peanut butter and thick pancake batter. Too much water/too runny a mix is no good.