Hello if i may i would like to pick your brain for a second. I was just wondering about humidity. Is there a certain humidity you dont want to go over or under?

Humidity has no effect on 100% solids epoxy wrap finish.

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Huimidity has negligible effect on two part epoxy. Some can even be used under water,.

Whoa Nellie, not so fast with the expert opinions. Humidity definintely has an adverse effect on curing two part epoxies. The typical hardener in our two part epoxies is a Polyamine compound. This materiel is a vertual sponge. It literally @#$%& moisture out of the air. If you mix your epoxy during high relative humidity conditions you run the danger of having a BLUSH phenomena on the cured epoxy. This blush is obvious by its oily appearance on the surface. It even feels oily, and is many times wrongly thought to be due to a contaminate. If your epoxies are stored loosely during high humidity conditions, the amine will gorge itself on moisture, then during the mixing -- even when done at low humidity conditions-- this blush will occur. The blushing phenomena has no effect on the structural qualities of the mixed epoxy, but it must be removed prior to painting or adding another coat of epoxy.
One of the main goals of compounding LS Supreme was to use an amine hardener which minimizes this blushing condition. Mission accomplished.
Store your epoxies--especially the hardener-- in a covered area, away from excess heat, and excess cold. If you live in a high humidity area, keep your bottles capped tight, and if you mix them during high humidity conditions, be sure and keep the m;ixed resins from exposure to the outside high humidity.
Ralph

Ralph I guess the next obvious question is: what would be considered to high a point in relative humidity to epoxy, coming from the sunshine state AKA the humidity state I have seen this blushing occur quite often and as you stated assumed it was some type of contamination,

John,

I don't know the technical value of this, but in my book I said that as a general guide "if you are comfortable, your epoxy will be also". That was and is the general rule I give to people who ask about temperature and humidity effects on epoxy. Properly mixed, the stuff is going to set up and function well no matter what the conditions, but temp and humidity extremes can change the time frame and appearance when this will all take place. Most of us are working in areas that are between 60 and 80F and with non-condensing humidity conditions. Epoxy seems to work well in those same conditions.

I have purposely mixed and applied epoxy finish during times of high humidity (NC is "wet", even during 100 degree clear summer days with humidity usually between 80 and 95%) even going so far as to open the doors during rainstorms. No ill effects have been found. I have also poured freshly mixed epoxy into a glass of water and the stuff set-up perfectly, albeit with some whiteness/blushing around the edges of the cured epoxy.

I suppose there are several ways that moisture can get into your epoxy, but I suspect you'd have to store your epoxy bottles without the caps on or perhaps apply finish over an acrylic color preserver that isn't completely dry yet.

Ralph can give better information that I can on this, but I feel perfectly comfortable mixing and applying epoxy in any level of humidity as long as it is "non-condensing". Most of the problems that rod builders attribute to high humidity are, I suspect, really coming from other areas such as improper mixing and measuring and not from the humidity.

I'll stick to what I have said for years, that is if you are working in a place that you find humanly comfortable, your epoxy will work as intended. That's about the best general rule of thumb I can come up with.

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I agree with Tom's assessment 'if you are comfortable, your epoxy will be also'. To answer John's question about what would be considered the high point for RH --- There is no possible answer to that one as there is no one point for all types of amines. Here in the Northwest we are not considered to be in a high humidity area, yet I have known of most of the local rod manufacturing firms to be shut down for a few days when the right conditions come along. About 10 years ago I worked with one of them and helped coerce them into an air conditioning system to prevent further shutdowns in the future. In this country, the phenomena occurs for two or three days about once a year. I have never been able to induce blush conditions artificially. I have closed a room and introduced steam via the boiling tea kettle route, let the epoxy hardeners stand in the room for several hours, then mixed and applied the epoxy in the steam room. Everything came out like I was making a show piece for the president. It is well known and widely accepted in technical journals that high humidity is what causes blushing, because of the amine ingesting moisture from the air. What is not known is where the line is drawn--if there is such a thing as a line. Will 95% RH cause blushing? Does it have to be 98%? I doubt very much that Tom will be able to induce blushing with wet threads, but it will be interesting to see how that experiment turns out.
There is no problem in encountering moisture after the epoxy is mixed and the reaction has set in. The amine tends to absorb moisture before it is combined with the epoxy, then upon mixing the blush phenomena is apparent. However the amines seem to have a mind of their own. They are not just about to play ball in your back yard, they will only play ball when you least expect it, and can least afford it. Several years ago one of the local manufacturers called me on the phone and asked me what the devil is going on----his explanation made me suspect it was a typical blush phenomena. I dropped what I was doing and mixed up some DuraGloss and was quite suprised to see the worst case of blushing I have ever witnessed. This atmospheric condition lasted for three days, and had their rod production completely shut down.
Technically this blush condition is amine carbamate, and with the water vapor there must be carbon dioxide present in order for it to form. It appears oily but is actually water soluble and can be wiped off with a damp rag. It must be removed prior to applying another coat, but no other preparation is necessary--just wipe if off and go.

Epoxy BLUSH is a little understood and seldom recognized rod builders bugaboo. It is not in the category of being troublesome, but it is the cause of an odd witch hunt here and there. Some areas never ever see it, some areas -Atlantic seaboard states, NE in the summer time- it must be ripe for the condition several times a year. These areas also fit Tom's definition, because they most certainly are not comfortable to work in. All rod builders that use epoxy finishes would be wise to learn to recognize it and allow for it.

Ralph

I have experienced this blush thing since I moved from colorado to minnesota, I was wondering why it happens, and it seems to wipe right off most of the time, maybe with some alcohol if necessary, but.... sometimes it won't come off, I have a rod sitting right now, where it dosn't seem to want to come off, is there anything I can try to get rid of this, or is it re-wrapping time? the blush theory really make sense, because it seems to get worse the longer I have a bottle of finish, I use regular flex coat, which is hard to keep tightly capped with those stupid ketchup-tops which I don't use anyway.