I spray painted a craft project with a clear coat and it crackeled!?

I use this spray all the time on these same things, but sometimes it crackles and bubbles up! WHY? I know the under coats were dry. I spray painted a craft project with a clear coat and it crackeled!?
Hi,





If you give more than one coat of clearcoat, do you wait the correct time between coats ? Usually 10 to 15 minutes.


There are several causes for cracking :





1 - you wait too little time between coats and the solvent doesn't evaporate. The top coat dries faster and gets harder. Then when the under coat dries, it forces the harder one to crack.





2 - you wait too much time ( lets say 1 hour; one day would be okay).


the second coat's solvent will attack the previous coat that is curing).





Solution : follow the instructions in terms of timing. Usually is 10/15 minutes between coats (thin ones). But better read instructions.





These are times for normal temperatures about 20 celcius (dunno F).





Kind regards,





Jos茅http://theartinquirer.blogspot.com

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