Is Diamond Brite Bond Coat Necessary?

A bond coat may be not necessary for a good chip job, but make sure the acid is throughly washed clean. A bond coat is a good idea for replastering on to old plaster that has not been chipped away, and is sand blasted only.
But sometimes a bond coat is an additional measure to take to avoid bond failure.
 
onBalance said:
A bond coat may be not necessary for a good chip job, but make sure the acid is throughly washed clean. A bond coat is a good idea for replastering on to old plaster that has not been chipped away, and is sand blasted only.
But sometimes a bond coat is an additional measure to take to avoid bond failure.

Thanks that makes sense. Good to know. Had some problems with discoloration and just can't seem to get a perfect resurface job done. we use clean water to mix. maybe the guys here just don't have the proper training to resurface diamond brite.
 
Its a pretty set recipe for mixing and applying. Discoloration is more frequently due to other factors after the plaster team is gone. Occasionally, the DB is over worked or has exceeded it's work time but that isn't the case often. The water, the brushing, the balancing, etc... all have a lot to do with this and if whoever owns it doesn't cure it properly, the discolorations will happen.

Bond coats make a smooth surface roughened so as to reduce any delaminations. That's all it does.

Scott
 
The type of tap water, the brushing, the balancing, has nothing to do with plaster discolorations and proper curing. Severe gray mottling discoloration (which is very smooth to the touch) is due to overly late hard troweling and the addition of excessive amounts of calcium chloride to the plaster mix, and will not be countered, offset, prevented, by any kind of various water chemistry balancing. The plaster compounds (material) are affected by improper plastering practices. The addition of calcuim chloride to the mix affects the curing and hydration of the cement. Calcium Chloride speeds up hydration of some of the cement components, and slows down other cement components, which leads to discoloration mottling. And late, hard, and dry troweling will darken the cement color by reducing the water content. That is what affects the "curing" rate of cement, not tap water or water chemistry balancing.
 
It needs to be pretty cold out to be adding calcium chloride.
A missing ingredient to discoloration is not wetting the shell first. A dry shell will draw moisture away from the plaster and into the shell.
Adding water to the mix to make it easier to work when it's too old is another bad ingredient. This is similar to the hard troweling that onBalance referred to.
Cement based products such as plasters undergo a chemical change called hydration. This is why we wet down the shell when it's shot, cover slabs, etc... The moisture they contain is important to the chemical changes taking place. Plasters need the pool filled fairly quickly to ensure this process is uniform, by and large.
A big problem with well water in my area is iron in the water. Other areas may have hard water or large amounts of calcium chloride in the water which shortens the working time of the plaster used.
Diamond Brite is effected by water chems though and in my are, is often indistinguishable from the applicator errors that can happen. I have seen people use cal-hypo and dichlor on fresh plaster without premixing it. I've seen acid added away from a return and undiluted. I can think of others but you get the idea.

Scott
 
Thanks for all that info guys.

Being that I'm a one man operation I'm staying away from resurfacing and renovations as they pull me away from pool management and SWG installs. The two things I do best.

Resurfacing seems like a great deal of work and is time consuming. No wonder it is pricey. But most people don't want to pay to have it done right. At least around here the lowest bidder gets the jobs.
 
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