Some SBC questions

[RTflorida]

Re: Some SBC questions

Leave it built up a bit in those corners. Think of running a bead of caulk in a corner and then running your finger down it to smooth and remove excess - it leaves a lightly built up curved bead (cove). You don't want to apply it and then scrape it all off trying to maintain a crisp 90 corner.
Cove molding is used in wall paneling installations, wood siding. In those apps it is primarily used to hide a "boogered" job of installing the corners. Makes sense to cove the SBC - added strength in the corners as well as aesthetics - crisps corners are not easy to achieve with most masonry products

RT

[ThisOldGarageNJ]

Re: Some SBC questions

Hi Keb,
when you are applying it with the trowel, you will see that it can be left very flat and smooth, You have to have a real good hand to get it flat.. I applied a square foot or two then rubbed in a circular motion with a grout sponge (just a big sponge for cleaning grout or washing cars) after putting on the next batch I would sponge again and overlap to smooth out any seams/joints, as it was very hot out when I did it I kept the dome vermicrete damp as I applied it and misted it after as it was curing/drying..... I also used the Acrylic fortifier

QUIKRETE? Concrete Acrylic Fortifier (No. 8610) is an acrylic resin admixture designed to enhance bonding and water resistance of concrete patching materials, stucco, surface bonding cement, thin-set mortars and tile grouts.

and the color, the fortifier seemed to help it spread easier, The color was good, BUT it faded a lot in a few months... Im sure I will be painting my dome in the next few weeks..

Good Luck
Mark

[kebwi]

Re: Some SBC questions

The directions seem to be along the lines of one gallon of water per fifty pound bag, with an allowance up to one and a half gallons of water. In addition, the directions for the acrylic modifier are to "add" half a gallon per fifty pound bag.

The question is: is the acrylic modifier really additional, or does it supplant the water, thus only half a gallon of water per bag?

[ThisOldGarageNJ]

Re: Some SBC questions

Hey Keb,,
If I remember correctly, I bought an empty 2 gallon paint can, Measured in one gallon of water, added the liquid colorant (which wasnt much) then the acrylic fortifier.. I used the total of 1 1/2 gallons of water,colorant,fortifier Mixed together as my liquid amount and it worked out fine.. I also mixed my SBC in a mixer, It is recommended by Quikrete, though many have mixed it by hand,, I also recently have mixed smaller batches with my 1/2 inch drill and a paddle mixer and it seems to work fine..
Cheers
Mark

[ThisOldGarageNJ]

Re: Some SBC questions

Keb...
Some Additional Info:

MIXING
Machine mixing is recommended. Mix
1 gal (3.8 L) of clean water with each 50 lb
(22.7 kg) bag of QUIKWALL SBC. Place the
water in the mixer and add the QUIKWALL
SBC to the water. Adjust water as necessary
to achieve desired consistency. Do not use
more than 1 1/2 gal (5.7 L) of water per bag.
Mix no more than 3 minutes to avoid filamentizing
the glass fibers.
CURING
QUIKWALL SBC walls must be fog cured after
having achieved final set. This is essential to
ensure proper hydration of the thin surface
application.

• Only clean water should be added to the
QUIKWALL SBC. This particularly excludes the
use of antifreeze in winter. The product’s
formulation will be altered by the addition
of foreign materials. QUIKRETE Acrylic
Fortifier can be added in accordance with
the manufacturer’s specification

Or give us a ring on our Help Line at 1-800-282-5828

QUIKRETE? - QUIKWALL? Surface Bonding Cement

Here is the link and their help line number, I called their help line 2 or 3 times with questions and they were very HELPFUL......
Cherrs Again
Mark

[kebwi]

Re: Some SBC questions

Yeah, I have all the official spec data you sent. The PDF is available on their website but its wording is totally ambiguous as to whether the acrylic fortifier is in addition to the water or as a substitution for some of the water.

I've also emailed them for help.

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.

[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

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

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.

[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

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.

[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, 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.

[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