Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: xchcui on November 24, 2022, 09:36:42 AM
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Hi.
Some high temperature(800°C)spray paints have to be baked in oven(around ~180°C)for a several minutes to fully cured. Without the baking process(the instruction states)the paint coat won't reach its full resilience(fuel-resistance). In regards to that statement,i understand that the ~180°C,apparently,activates the materials in the paint so the coat will be at the full resistance,but,nevertheless,why this process can't be done by left the painted object in a direct sun for several hot days? Maybe,it won't happen the same speed as in the stove, but won't it happens eventually?wouldn't the extended heat from the sun will activate eventually the materials in the coat even that it is lower than 180°?
Thanks.
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130K difference is too much. Just 60K make the difference between a chick and a boiled egg.
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Okay,i see your point.
So,even after 10 years in the hot desert,the chemical reaction in the coat won't happen,as it will only happen at ~180°C.
Thanks.
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That's even more complicated - for the reaction to proceed it may need a right combination of temperature and substances which are part of the mix but are volatile or decompose. So it is possible they can survive for long enough to help with curing if done relatively quickly at 180, but can be not there later even if the process happens to be possible (just slow) at lower temperatures. Many possible fine prints here.
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That's even more complicated - for the reaction to proceed it may need a right combination of temperature and substances which are part of the mix but are volatile or decompose. So it is possible they can survive for long enough to help with curing if done relatively quickly at 180, but can be not there later even if the process happens to be possible (just slow) at lower temperatures. Many possible fine prints here.
I didn't quite understand your explanation.
Did you mean that with time,the substances that responsible for the curing may volatile or decompose,so even if i would like to bake them at the proper temperature,they won't be able to fully cured,because of lack of those substance?
If,yes,how long is it about(from the moment the coat applied),that the coat won't be able to full cured due to lack of those substance?
weeks?months?years?
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Did you mean that with time,the substances that responsible for the curing may volatile or decompose,so even if i would like to bake them at the proper temperature,they won't be able to fully cured,because of lack of those substance?
I am not saying this is the case - but it is definitely a possibility.
If,yes,how long is it about(from the moment the coat applied),that the coat won't be able to full cured due to lack of those substance?
weeks?months?years?
There is no "one size fits all" answer, as there are plenty of possible polymers and they have different polymerization mechanisms. In general I would prefer to bake it no later than the next day after painting, just to be on the safe side. (Unless the recipe clearly states it should be done differently).
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Okay,got it.Thanks for your advise. :)