AQUACOTE application

Discussion in 'Materials' started by ozyjack, Jul 26, 2018.

  1. ozyjack
    Joined: Jul 2018
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    Location: Gold Coast, QLD AUSTRALIA

    ozyjack Junior Member

    Hi out there.
    I have used a system called Bote-Cote and Aquacote and have noticed a grey blue haze in the Aquacoat surface. I believed I followed the instructions to the letter. The supplier believes the haze will disappear as the weather warms up, which it may well do, but I wouldn't consider the weather to be cool at the moment, I applied the coating when it was 22 degrees Centigrade which is approx 71 degrees F. the haze is also uneven or blotchy.
    I would be very interested to know if anybody out there has used this product, and who may be able to enlighten me as to what I might be doing incorrectly.
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

  3. rwatson
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    rwatson Senior Member

    When you say "a grey blue haze in the Aquacoat surface", do you mean IN as UNDER the surface ?

    Amine Blush is only on top, or course, unless you have recoated OVER a previous layer, and failed to clean the previous layer after curing.

    If you are expecting a clear, bright permanent finish over timber, few Epoxies guarantee that, except the special and expensive West Systems special formulae.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Overnight temps in the vicinity of 5-8 degrees C in the OP's area in recent weeks, may be implicated. Humidity has been generally quite low, though.
     
  5. ozyjack
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    ozyjack Junior Member

    Thank you very much for the reference, "Mr efficiency", and your comments. I don't pretend to understand it all but I think my problem may relate to the initial epoxy coatings applied. While I believed them to have completely cured, at the time, and they were dry and hard before I sanded ready for the Aquacote ( 1- 2 days ) it would seem to me there is a good chance that they had not cured 100%. I didn't realize this, nor did the instructions emphasize the necessity of a complete cure. As a consequence, I think my only solution is to wait until the curing processes in both materials has completed and start again.
    My deck area is approx 1.5 sq metres, a 40 odd year old plywood, that I had to scrape the two pak off to get back to bear wood veneer in the first place. I see my problem now is going to be the removal of the epoxy and subsequent Aquacote coatings without going through a very thin veneer.
    Many thanks to " rwatson" also. The effect I am talking about is definitely under the surface, I have tried to remove by wet sanding with 360 grade paper. In the few places I have sanded back to the epoxy the clarity seems OK, however the rest of the deck looks more blotchy than ever, this of course may be due to the amount of Aquacote being removed unevenly and my putting fresh water into the mix by wetsanding?
    I have restored and refinished many a sailing dinghy in the past without a hitch, and the coatings have lasted 2-3 years. The Aquacote system suggested I might look for a 5-7 year life ( not stored under cover ) and a very much simpler and efficient re-coating system. When I think I have spent 1 month on this deck, even without the problems I have encountered, I am beginning to believe you can't beat an oil based varnish with regard to cost and time effectiveness, and If I can get back to where I started I will refinish with the oil based varnish.
    Thank you very much again for your imput.
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    Clear-coating is a potent source of grief, but was there any need for the epoxy bote-coat ? According to blurb on the net.... "The clear version of Aquacote Topcoat can be applied direct to timber using the same techniques that you would use for applying varnish and estapol. "
     
  7. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    Even blush free epoxies occasionally do develop aminee blush.

    What is your humidity?
    How thick is your coating?
    How quickly was it built up?

    I have20 years experience as industrial painter.

    Water bourne urethanes are prone to blue/green haze if water can't excape during cure. The blush should disappear with full dehydration.

    Occasionally, the haze will return if water contact is of leanthy duration.

    Was it sprayed?

    If overstay or dry-spray is overcoated, the edges of the dust coat can ghost thru.

    If it doesn't clear soon, try adding gentle heat such as a hair dryer to see if a localized spot will clear. Then most lickly hydrological cause. If is persistent, then could be amine, dry spray haze or other inter surface contamination and only cure is removal by sandpaper.
     
  8. ozyjack
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    ozyjack Junior Member

    Thank you " Blueknarr " I believe the humidity was within specification, less than 60%. I did do the epoxying outside, as well as the Aquacote, for that matter, and then moved the boat back into my well insulated garage, early afternoon. The epoxy coating was thick, I have to admit, as the epoxy was like " golden Syrup " and very laborious to mix. The pumps I purchased for the resin wouldn't pump it without great exertion, and I relented to using a clear plastic measuring cup graduated for easy measurement of levels. I was later told to warm the resin which I did in a warm water bath which made the resin flow much more freely. I still suffered runs with the resin on the deck, which when brushed out just returned, so I resolved to sanding them out once cured. the build up of coats were made while the underlying coat was tacky. I thought the overall appearance of the deck,with just the epoxy coating, was excellent apart from the runs which were subsequently sanded out.
    Once sanded the deck was then washed with soapy water and well rinced before applying the first of the Aquacote coats.
    The first three coats of Aquacote were applied with a foam roller to begin with but this left air bubbles that didn't wan't to come out. I applied 3 coats at first instance and then sanded back with 240 grade wet to get rid of the bubbles. After sanding, a further 5 coats of Aquacote were applied by high density foam brush as supplied by the aquacote people. Subsequent coats were applied when the prior coat was touch dry, probably within an hour of the previous coat. I noticed that the coats took about 20 minutes to be touch dry, all in accord with what I had been advised.
    With regard to thickness the Aquacote information sheet indicated a coverage of 10 sq metres per litre. My deck area is approximately 1.5 sq metres. To date I have applied 8 coats, 3 in the first session, 5 in the second. I have encountered no real problems in applying the Aquacote, it flowed on easily. I have approximately another 3 x coats left in the container. This would suggest I am getting a better coverage than the published coverage, thereby my coats would have to be as thin if not thinner than they should be. The fact also that the whole of the deck, not just a particular area, exhibits the grey blue cloudiness would also tend to suggest, to me at least, that I have not applied the coating “ too thickly “?
    Any further comment or advice would be greatly appreciated.
     
  9. ozyjack
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    ozyjack Junior Member

    In reply to "Mr Efficiency", my understanding is that the water based polyurethane which has excellent UV protection, but not so good water protection. The idea of the epoxy is to waterproof the timber, the Aquacote to protect the epoxy from UV light.
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    OK, I am not that familiar with water-thinned polyurethanes. Some finishes can raise the nap of different types of wood, too.
     
  11. rwatson
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    rwatson Senior Member

    The local boat association tried the water based poly on one of their projects.

    It lasted a season at most. Very disappointing.
     
  12. Blueknarr
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    Blueknarr Senior Member

    Some of my observations
    Most paint manufacturers recumend humidity less than 50%
    Amine blush should have been eliminated

    5 coats in 5 hours is very aggressive build up. I wouldn't advise more than 3 coats per day at 70 degree Fahrenheit, especially if it is cooling greatly at night as was stated in an earlier post by Mr E.
    True
    That the problem is nearly consistent across entire deck suggests to me that it is either an application issue or faulty paint. The first occurs far more frequently than the latter.

    Have you tried force drying a small area?
    I still think trapped water is the culprit
     
  13. ozyjack
    Joined: Jul 2018
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    Location: Gold Coast, QLD AUSTRALIA

    ozyjack Junior Member

    Hello " Blueknarr" and thank you very much for your detailed reply. Would you mind advising me on the following -

    1. When I put the first three coats of epoxy on I got runs which I sanded out using a professional palm sander and finished off by wet sanding the whole deck. I chose to wet sand to avoid the dust from the epoxy. I was fairly aggressive with the wet sanding 240 grit to remove the remnants of the epoxy runs, I was loathe to use the palm sander too much for fear of going through the veneer, also the dust.I think I left it a day or two before applying the Aquacote.
    Could my use of water when wet sanding and the subsequent washing of the deck caused this " amine " blue grey blush?
    I don't recall seeing any blush in the epoxy coating prior to sanding and washing it, ready for the Aquacote

    2. I noticed the blue grey blush after applying the first three coats of Aquacote. The advice I received from Aquacote was that the blush should come out of its own accord as the Aquacote cures. I was advised that I could keep applying the Aquacote , that the additional coats would not affect the curing of the first three coats. ( Please note Aquacote have not inspected my deck only seen a picture ).
    Because the first three coats had air bubbles ( I used a foam roller purchased from Aquacote ) and I could still see the faint outline of where I had epoxy runs, I wet sanded the deck again with 240, this cut through he Aquacote where the runs had been.
    Again the deck was well washed with soapy water and rinsed off after before applying more Aquacote.

    3.The instructions suggested to start applying Aquacote mid morning when it was still cool, and suggested 4 - 6 coats should be applied before the two finishing coats.
    My advice from the company was that I could reapply Aquacote once touch dry. I found that the Aquacote took about 20 minutes to attain a touch dry status and on average I guess I would have applied a coat every 40 minutes to an hour. I completed the job a bit after 3.00 pm, maybe 3.30? The boat was moved back into the garage immediately after.

    4. The blue grey blush is more apparent standing in front of the job with the light behind.
    In direct sunlight some angles showed very little sign of the blush, other angles it is very apparent.

    5. I have had the boat out in direct sunlight twice, for about an hour each time, the deck felt more on the hot side of warm, I suppose I have given the deck a total of two hours of sun exposure, I will put the boat in the sun again now.

    6. Regarding applying heat to the deck. What do you think if I put an oil heater in the garage and left it on for several days? Is that worthwhile do you think? Can I leave the deck in the sun all day?

    7. I noticed I had left my stirring stick which I had used for both the epoxy and the aquacote out on my work table outside. In the monings it looked quite milky grey on the edge, and this seemed to lessen as the day progressed. Yesterday I used my heat gun to heat the surface and noticed the aquacote " boil/bubble " under the skin of the Aquacote. The Aquacote would have been about a week old.

    8. Rightly or wrongly I sanded the deck after the 5 coats ready for the final two coats. This of course makes it most difficult to see the blush, The only way to check the deck is to wet it which just adds water to the aquacote again, increasing the problem? Have you any suggestions in this regard?

    9. I have been told by Aquacote that the blue grey blush should disappear as the weather warms up. But when might that be??? I had no inkling that the temperature was so critical as I get around during the day wearing a "T' shirt? According to the instructions provided I thought I was applying the Aquacote in very mild conditions and had nothing to worry about in that regard. I was told this product was loved by the boaties down in Tassie, if that be the case, my applications must have seemed like being done on a mid summers day?

    Thank you again for your time and effort in trying to assist me, I greatly appreciate it.
     
  14. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    This must be most frustrating for you. I am not directly familiar with the Aquacoat you are using, but I do have extensive experience with many other products. If my advice contradicts their tech support, take it with a handful of salt. My experience with tech support is that they read off of a script. If you truely need help they are generally useless.

    Background info for you:

    Amines are byproducts of epoxy curing. All epoxys have them, some more than others. They are water soluble and float to the surface of epoxy. A scrub pad and water permanently remove them.

    Fresh paint is still semi-permeable. When successive coats are applied, a small portion of solvent (water) re-enters the base layer. It eventually migrates to the surface were it evaporates. Low temperatures, high humidity, thick or extra coats greatly extend the time required for all the solvent to evaporate and full cure achieved. In extreme cases, the coating may become thick enough to prevent complete cure and stays spongy.

    My personal paint layup schedule for water bourne is max 3 coats per day for 3 days then let it rest for a week. Oil only gets 2 a day for 3 days and two weeks rest.

    No. You definitely removed all traces of amine

    They lied. Additional coats will slow the cure rate of first three coats
    Implies pause between first 4+6 and final 2
    Painting in excessive heat can cause the solvents to evaporate in incorrect sequence
    Good. The more Sun the better. For now

    Yes and yes

    Good sign. Usually thicker on edge. If blush is fading then it should fade from deck
    Way too hot!! Please tell me it was the stir stick which boiled

    Not really
    The transition of water is not instantaneous. Wet sand bit try to prevent puddles from standing on surface.

    Yup
    good question?
    What they said is technically true singularly but inaccurate collectively

    If it is any consolation: many years ago early in my career. I piled on many coats of clear water polyurethane onto a pick-nick table in the late fall. It took two weeks to clarify. The first winter it clouded up for a week after each rainstorm. Apparently it baked solid in the summer because it stayed clear all the next winter.

    I hope I have helped.
    Much of painting is timing and much of the timing is slow.
    Let the sun do its thing.

    Worst case you sand it off and switch to oil or lacquer. Instead of haze they get wrinkles or alligator if built up to quickly.

    Paul
     

  15. ozyjack
    Joined: Jul 2018
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    Location: Gold Coast, QLD AUSTRALIA

    ozyjack Junior Member

    Thank you very much Paul, I believe I have learnt a lot from your comments, and yes the heat gun was used on the stiring stick............... So OK I will stick with it.

    I will get the deck out in the sun as much as I can and I won't apply the final two coats until the grey / blue disappears....hopefully.

    I have probably removed a coat or two from the previous five coats, and I have sanded through to the epoxy in a few places. The Aquacoat has no filling qualities, which I understood from the start, and while the deck looked fine wet after washing ( as far as fairness was concerned ), the application of the Aquacote highlighted where some of the epoxy runs had been sanded down to just about next to nothing, but not nothing.
    You may be wondering why I didn't do a 100% proper job on the epoxy sanding in the first place.......The answer is, I was fearful of sanding through the top veneer of the plywood deck. The poor old deck I felt had suffered enough under my hand when removing the original old two-pak. To go through the veneer, at this stage, would be a mistake of catastrophic proportions, so I was erring on the side of of not creating a catastrophe for myself.

    One question - Should I give the deck another 3 coats of Aquacote, when the blue / grey goes and before the final two coats?
    The instructions suggest that the final two coats be watered down by 50% and applied with a damp wad in a circular motion, similar to French Polishing. So I guess the final two coats don't provide much depth.

    I have been amateur building, sailing and maintaining small dinghy's for in excess of 50 years now. I have always used marine varnishes, this was my first foray into water based polyurethanes. And you hit the nail on the head when you referred to my frustration. While for the water based system the application is easy enough, knowing the intricacies of the product and its application are obviously the key to a good job, and I guess this can only come with practice and experience.

    Will I use this product again, I don't think so. It is not that it isn't a good product, and I think I have learnt a lot from my current project, thanks to you and the other forum members. But the time one needs to spend on the job using this system , for me , is just too laborious, not to mention expensive. I have spent in excess of $200 in materials from the suppliers of Aquacote and I will probably have to purchase more before the jobs done. All this for a 1.5 sq metre deck. Had I used a good quality oil based varnish, I would have spent in the vicinity of $30.00 and have completed the job two weeks ago, a fact of life.

    I will be happy if I get my nice deck in the end, and I have learnt a lot in the process, I guess they are the main things.

    Thank you again for all your assistance in my project, I now feel reasonably comfortable going forward with the very generous information you have provided.

    Thank you Paul.
     
    Blueknarr likes this.
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