Some SBC questions

[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.

[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

[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

[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

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

[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

[kebwi]

Re: Some SBC questions

Ah, a slightly thicker 45 degree bevel. Makes a lot of sense. Um, how do I achieve that edge most effectively? I need a tool that unlike the nose of a trowel has a flat edge. Should I drag a screwdriver along the edge?

I can totally see the value of this, I'm just trying to visualize the most effective means of creating it.

[Tscarborough]

Re: Some SBC questions

It prevents cracking in the corners.

[kebwi]

Re: Some SBC questions

There you go with your insider vocab again. What is "coving"? I will have concave right angles in many places on my exterior: Where the two upper terrace walls meet the terraces below them and also along the bottom edge of the inside face of each planter wall.

[Tscarborough]

Re: Some SBC questions

It is always trowel application, then after it takes an initial set you can come back and give it a sand finish (sponge it). Don't forget to cove the SBC anywhere there is an inside right angle.

[kebwi]

Re: Some SBC questions

Getting closer to the SBC day...not there yet, still some more brick work, but closer.

The surface my SBC will be applied to is horizontal terraces of ordinary portland concrete and vertical walls of hardibacker. Should I mist or damp either of these two surfaces before applying the SBC?

I'm curious about ways of achieving various end results. Previous posts (in this thread) have mentioned troweling and sponging. I'm a little confused. How could the end result *not* be troweled, in that a trowel is the primary means of application? What would be the alternative?

As for sponging, I like the idea of a rough surface, it might help moss grow all over the oven. How long should I wait before sponging? Should the sponge be damp? Do I drag the sponge or just dab the sponge? I would be worried that dragging might destroy the SBC.

[ThisOldGarageNJ]

Re: Some SBC questions

hey keb...
QUIKRETE? - QUIKWALL? Surface Bonding Cement The stuff is so easy and you can definitely do a full bag with no problem, Unless,,, your going to trowel finish and you may need some more time for that, I troweled it on and then worked it with a sponge a rougher finish that I found pleasing..
Cheers
Mark

P,S. I used the acrylic fortifier as well

[kebwi]

Re: Some SBC questions

Yeah, I have the acrylic fortifier. I'm going for maximum water resistance.

[sjmeff]

Re: Some SBC questions

I drill mixed full bags of SBC in a mortar tub (I didn't want to pay for a rental mixer). I don't think you need to do half bags. Are you planning to use the liquid fortifier? In addition to making the SBC more water resistant, it makes the curing process easier (you don't have to keep it wet), which for me was worth the added cost. It may have also kept it workable longer. I found it easy to apply and it went on pretty quickly. Just keep the tub out of direct sunlight.

I had lots of imperfections in my vermicrete that the SBC covered just fine.

Also, I overbought for the reason you described (not knowing exactly how much you need) and then I returned the unused bags.

[kebwi]

Re: Some SBC questions

So, I just ordered some of that oxide colorizer you found on ebay for me. Thanks.

I'm still nervous about applying the SBC, it's kind of expensive and I have one shot.

Tolerate some more questions please...

Someone mentioned above that they did half-bags, mixer-mixed. But I have read that the SBC sets/cures/dries-out fairly quickly, so I am considering using smaller batches and drill mixing them. How much can I confidently mix and apply at once before it starts to go bad? Is it a small enough amount that I should drill mix it (couple of quarts max) or can I really do a reasonably large batch (in the mixer) without it going bad part way through?

Unrelated question, anyone following my build knows that the structure I am applying SBC to is a set of terraces. The vertical walls are hardibacker and the horizontal terraces are vermicrete (there will also be some thin concrete blocks running a short wall around each terrace to form a planter bed). I am considering parging the vermicrete with sand/portland/maybe-lime before applying the SBC. I can't really say why, it just struck me as an idea. I figured I would fill the voids and solidify the loose aggregate with a portland mix first, then SBC over that. At the least, it might save me SBC to apply to a smoother surface, on the off chance I don't have enough in the first place (which I can't really gauge in advance of course). Does this make any sense or should I just SBC the raw vermicrete, regardless of divots, loose chunks, etc.?