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Stucco and rewettable bonding agent

4.4K views 3 replies 2 participants last post by  ClarenceBauer  
#1 ·
I am working on a larger exterior wall with existing stucco, and I am adding another 1/2" over the existing stucco that's been there for over 20 years.

The wall is large and will take me multiple days since I can only do it after work before the sun sets. I am applying a blue bonding agent by Lanco:

Lanco Blue Fortifier and Bonding Agent CB-610 for plastering or plastering mix, homopolymer emulsion based adhesive and fortifier for interior/exterior use. As an adhesive it dries fast to promote a strong bond between old and new concrete, stucco, stone, wood, brick and tile. As a fortifier it provides resiliency.

The question I have relates to the use of this bonding agent. I applied the bonding agent over half the wall on day 1, thinking I was able to do half the wall, but I was slow. Plus I have to wait 2 hours after applying the bonding agent before putting on the stucco per instructions.

So I end up covering 1/3 of the wall only.

Now on day 2, I have some of the old bonding agent on the wall, the instructions said if I waited over 24 hours, I should recoat a new layer. In my case it's right at 24 hours. Should I recoat a new layer before waiting 2 hours and do another 1/3 of the wall?

Finally, these are rewettable, does it mean it will come apart when wet? since I am doing one section at a time, I am misting the section I did yesterday afternoon, and some of this mist sprayed over to the section not yet done, so that wall is partially wet, now on day 2, can I put new bonding agent onto a section of wall that's been partially wet from overspraying? Or I should stop misting the wall while I am working on it, but then this will cause the fresh stucco to shrink too much too soon right?
 
#2 ·
Re-wet able means that you can apply a wet mix of a plastering material over the bonding agent up to 24 hrs. after you have applied the bonding agent. If the 24 hrs. has elapsed you must apply a second coat of the bonding agent.
After the bonding agent has cured 24 hrs. it will not form a bond with the wet mixture applied over it.
 
#3 ·
Thank you Clarence, two more questions if I may.

I read the instructions and the bonding agent said wait at least two hours before laying mortar/stucco. Yet others said as soon as it's tacky it's ready to go which seems to be a much shorter wait time as when I tested it after 45 minutes it's already dry to touch.

If while misting the previous day's fresh stucco I end up spraying on the existing stucco to cause it to get wet, should I wait till it's 100% dry before I roll on the bonding agent?
 
#4 ·
I would assume that depends on the chemical make up of each type bonding agent yours stated 20 / 30 min. before applying the plaster material & recoat if time exceed 24 hrs. I don't think your misting over spray would have any effect on it.
Did you check on using Weld Crete bonding agent they have an open time of a couple days were you can apply the plaster material.
Also make sure the plaster is not to dry when you apply it.