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temperature and finish10/12
I had a finish rep tell me that storing solvent base finish at below freezing temps affects the finish properties even after being warmed up before use. He also stated that finishing below 68 degrees can affect adhesion and long term durability.
Have any of you been aware of this?
Oh; of course.
My question did sound kind of dumb. We have sprayed lots of finish below 68 degrees and to my knowledge have not had a problem. Maybe this sounds just as dumb but how important is the 68 degree limit?
Our Fire deparment inspector had us vent our Fireproof storage box with a intake pipe from outside the building and a exhaust pipe to outside the building as well, so basically bring outside temperature to inside our storage box. So i told him that we need to keep the temperature of the cans above 66/68, he had no answer, he look at me like i had two heads. Back to your question, we keep the temperature inside our shop 66/68, and no , we don't store our cans inside that stupid box, but we need to have by code!!
I kinda got a chuckle out of your question Gary. My answer was meant to be in humor.
The only time Ive experienced an issue was when the coating was applied and the shop conditions were below 55*.
Once bit, twice shy. I followed the Manufacturers specs from that day on.
With pre-post lacquer coatings Ive pretty much stayed within the manufacturers specs.
Regarding conversion varnishes (ML Campbell and Sherwin Williams, my two main experiences over the past 14 years), I do not recommend at all that you spray and cure it below 60 degrees. Anything from 60 to 70 has historically been "barely sufficient", but sufficient nonetheless.
Sherwin Williams recommends very strongly that 70+ be your target curing. I know for sure that I see a remarkable difference in the curing speed of CV when temps go below 70. It's like a light switch. Below 70, cures slow. Over 70, cures quickly.
As for storage, we are in the coastal southeast, so we store stuff in a shed/container outside. It's big enough that we don't have problems with the finish dipping below freezing (as long as we don't leave doors open at night). If we were anywhere north of here, it might be an issue and we might need to find some way of keeping the temps reasonable. After 14 years of this sort of storage, we've never had a single issue related to this.
Have sprayed all coatings in 30 den during winter...
Never a problem. Tho Cv can give texture issues..
I lacquer on the other hand...np
Been in same business for 25 years. Never an issue...I try and use a bullet heater in stage area.
Now I use a heated forced air booth and spray at 75, Force cure at 120-160
From a production standpoint, I can assure you that the Sherwood and Kemvar lines of CV from Sherwin Williams cure vastly slower below 65 (really, below 70, it's that noticeable).
We can thin them with hotter thinners, like standard lacquer thinner, but that only helps just a little. It does nothing to accelerate the slowed catalyst reaction.
I've had times that I couldnt' sand the finish reasonably well unless it had several hours of cure time, when in better weather (over 70) we could have sanded it 30 minutes after it was sprayed.
Indeed, cure times in low temp are seriously delayed. cold weather makes the finish harden with out curing...
In all cases I would add a bit of mak, toluene or butyl cellosolve to delay cure depending on coating.
Cv can have texture issues
My issues always came after it began to warm up late in day..even after 24. lacquers would get tacky from not curing properly which made handling and packaging problematic..
No fun in cold weather