Defect case: Short oil Alkyd+ MF based paint. Applied a thin layer direct to MS metal by heat curing at 180 degree C for 10 minutes ,paint is well, no swelling.
After that, when trying to cover uneven surface by making same paint putty(adding high mesh calcium 50/50 in same paint) for 60 minutes at same heat and occurs swelling that putty.
That case which by? Paint or surface or application procedure?
Problem identification : There should be moisture entrap when 2nd layer applied. Or uding unknown solvent. Or 1st layer does not dried well. Or putty PVC changed in alarming. Or MF grade varying.
Solution: Should be confirmed 1st layer dried well. Use tru solvents. Use binder when adding CaCO3 powder. Check moisture before and after of 1st coat application. Choose right grade of MF.
