Cabot's turning black?????

[nitrox2595 15]

Has anyone had problems with cabot's 9200 series turning very dark and black? I have done several decks last year that have turned black in the floor areas. I called cabot's, and they told me to try problem solver, which I did, and it worked in some areas, but not all. I think i started noticing it when they complied with the EPA VOC laws. My dealer mentioned to try 1oz thinner to 1 gallon of stain. Anyone have any ideas??

[Cat Powerwashing Inc. 17]

re strip, nuetralize with ox or citrilic. then re apply sealer at this point. I hope you did that from the beginning.

[nitrox2595 15]

yes, we did, that's what i can't understand. It occurred on #1 cedar w/no knots. And other types as well.

[Cat Powerwashing Inc. 17]

Hmmmmm. Thats strange? was the wood nice and bright when you nuetralized? is the black mildew stains? If so, Give it a quick cleaning with your house wash. other than that, I don't know. Maybe you had a bad batch of cabots. i only use wolman products.

[plainpainter 217]

it's just mildew growth - throw a couple cups of bleach into a gallon of water and spread it over and rinse. Some products haven't evolved with the newer VOC

laws - and for some reason the same mildewcides that worked well in the past no longer work with newer formulations. Don't overthink it.

[big mike 14]

Sounds like the Penofin "blue label". That stuff always turned black because of the "exotic rosewood oil" formula. Mildew loves that stuff.

[Chesapeake 14]

it's just mildew growth - throw a couple cups of bleach into a gallon of water and spread it over and rinse. Some products haven't evolved with the newer VOC

laws - and for some reason the same mildewcides that worked well in the past no longer work with newer formulations. Don't overthink it.

Dan's got it right. When Cabot changed their formula to become VOC compliant, they had to take alot of the solvents out of the product. Unfortunately this allows the mildew to adhere to the surface much faster. The product hasn't failed, its just mildew growth on the surface. There's no real solution to the problem, other than washing the surface with a light solution of bleach and water. The mildew will usually return within 12 months.

[Beth n Rod 1,279]

At times it is on top, we have seen this with many products. But we have also seen instances ( with the Aussie Oil) where it was IN the finish. Most of the time you can clean it up. We have found that since the VOC laws changed the need for maintenance service has been greater, the longevity of the products has diminished, the need for service comes sooner. Most clients seem to understand it.

Beth

[plainpainter 217]

I have a theory that the majority of the stains post 2005 were formulated with softer resins - as it seems the new formulations didn't dry as hard as the previous

formulations. And this leads me to think the harder curing stains of the past were better able to lock in the mildewcides from leaching out too quickly. Where

as these newer softer curing stains I am hypothesizing do not lock in the mildewcides as effectively and thus mildew growth takes place sooner.

[James 624]

If a finish stars to break down and absorbs moisture. Mildew will grow faster and we had a ton of rain! Also if your prep was done with a pre carb there is more of a chance mildew can grow through the finish. That subject is never brought up . Pre carbs are not the best for killing mildew ?

[plainpainter 217]

Jim, sodium hydroxide followed by oxalic acid the best at killing mildew either? I don't think we are actually killing mildew the majority of the time - rather I think we are actually removing a layer of wood where the mildew

rests upon. I don't think percarbs are the best either at killing mildew - but if you remove a layer of wood - does it really matter?

[Beth n Rod 1,279]

It matters that you can't see a mildew spore with the naked eye....

Beth

[James 624]

Dan u r correct ? U can't remove wood if it's not degrade unless u sand ! If a deck is new and up to 2 years old the amount of degradation varies greatly between the species and it's orientation to the sun , weather and mill glaze. I am involved with starting care programs for new decks and my use of Bleach evolved out of the problems I had with precarbs on newer wood and getting rid of mildew and partial degradation.

[plainpainter 217]

I agree, you can't get decks easily cleaned unless there is an even layer of degradation. And I experimented with cleaning a new pressure treated railing the other

year I installed that had mildew growing all over it with percarbs. There was always a shadow of where the mildew was in the wood - and I believe it just grew right

back a few months later.

I am also done with the idea of new wood care. I know the argument about protecting the integrity of the wood before nature ruins it. But everything I tried on

ACQ lumber suggests to me that nothing penetrates and nothing sticks. What' the point of trying to protect the wood if nothing works to protect it?

I think Scott/OPW has the right opinion - if folks absolutely demand their new deck stained - use something like timberoil and tell them it will be gone in 12 months

and will have to get it redone.

[James 624]

Dan ,the new ASQ actually takes a lot of oil just very slowly. I hadn't done much new PT in a few years but did a couple last year . On a deck that I've been taking care of a few boards were replaced that were ASQ and new. I laid down 10 thin coats and all disappeared ( 2 boards by brush). The 2 decks I did less than a year old took one gallon per 100sqft 2 coats 24 hours apart RS. What I have noticed is the wood is much smoother almost burnished which makes absorbing oil much slower. I buffed one deck to scuff up the surface a bit ? I need to do more new ASQ and look at the surface more to come up with a better conclusion but the those two replacement boards drove me nuts because the oil kept disappearing.

[plainpainter 217]

I replaced two boards this past fall for a customer, wasn't a strip - just a major percarb clean, sand deck and reapply Benjy Moore's oil semitransparent stain.

This deck was done like 5 times, so it was solid in appearance. Even after screwing down the two boards, waiting for a couple rainstorms to try and leach

some stuff out, and then cleaning with percarbs, ox neutralize, and then sanding with my floor sander - the stain still just sat on the surface and was very 'thin' in appearance.

Maybe readyseal's parafinnic oil absorbs alot better - timberoil which is supposedly parafinnic didn't seem to absorb either on a board I replaced. The only products

I found to really absorb are like those cretowood water based products, that stuff disappears into the wood.

[big mike 14]

I need to do more new ASQ and look at the surface more to come up with a better conclusion but the those two replacement boards drove me nuts because the oil kept disappearing

Jim, the ASQ is more "sponge like". We do about 50/50 cedar and PTP, and we've seen a lot of the newer ASQ treated stuff. It really soaks up the stain, but I still only go 2 coats. I'm kinda working on the maintenance for it too, but like you, we use bleach for maintenance washing and it seems to do the trick. I have three ready to go this spring that were new, and need a color coat this year. We'll see if it absorbs like it did when new.

I like having some testing to do. Makes the work a bit more interesting.

[plainpainter 217]

Is ASQ yet another form of pressure treated or are you guys misspelling ACQ?

[ShineBrite LLC 14]

Is ASQ yet another form of pressure treated or are you guys misspelling ACQ?

ACQ is the common pressure treatment.

[James 624]

I wrote the wrong letters !

[Beth n Rod 1,279]

CA-B is a very common pressure treatment as well. In our area, we see a great deal of it.

Beth

[Beth n Rod 1,279]

Has anyone had problems with cabot's 9200 series turning very dark and black? I have done several decks last year that have turned black in the floor areas. I called cabot's, and they told me to try problem solver, which I did, and it worked in some areas, but not all. I think i started noticing it when they complied with the EPA VOC laws. My dealer mentioned to try 1oz thinner to 1 gallon of stain. Anyone have any ideas??

Yeah, add some mildewcide to every container before you apply it.

This series is responsible for excessive mildew growth and the problems associated with it is the need to completely strip it off and sand the wood to remove any remnants of the product and then reapply with a mildewcide.

One specific issue was with a customer who after a couple of weeks of our completion of their Ipe deck decided to sand and stain their white oak deck furniture...while on the deck.

The drips and residue that washed off from rain that ensued within a couple of days created a mess of mildew everywhere in the vicinity.

They tried to blame our product, jet fuel and our judgment yet they used the 9000 series cabot ATO which did not cure completely, in addition to the multitude of coniferous trees surrounding their deck led to the need to strip it completely and recoat.

A/C suffered only as a direct result of the contamination by the 9000 series getting onto the surface of it..

Rod!~

Edited February 18, 2010 by Beth n Rod

[Beth n Rod 1,279]

I remember that job. It was a nightmare. But by the time we were done the deck looked great... again, and I don't think the home owner will ever do something like that again without asking our advice. The little quart of Cabot's they bought...well the wife said it was going into the trash before her husband even got home.

Beth