GELCOAT SURFACE SPLASHES

Talk Composites - The Forum for Advanced Composites

Back

GELCOAT SURFACE SPLASHES

Author	Message
shakir	s shakir posted 6 Years Ago Topic Details
s Group: Forum Members Posts: 3, Visits: 16	I have sprayed 600 microns of gelcoat fire retardant.After 24 hours curing when i sand the surface for finish with 400 grit sanding paper whitish spots become visible on the surface which become more prominent after clear coat sometimes resin tearing or resin separation although i spray layer to layer with flashoff time 20~30 sec. 1% of MEKP used. Last time i had checked the airline but there were no any contamination and air line was completely dry.
	Reply Like 1
shakir	s shakir posted 6 Years Ago Post Details
s Group: Forum Members Posts: 3, Visits: 16	+x shakir - 2/12/2018 3:12:21 AM I have sprayed 600 microns of gelcoat fire retardant.After 24 hours curing when i sand the surface for finish with 400 grit sanding paper whitish spots become visible on the surface which become more prominent after clear coat sometimes resin tearing or resin separation although i spray layer to layer with flashoff time 20~30 sec. 1% of MEKP used. Last time i had checked the airline but there were no any contamination and air line was completely dry. Can any one explain or how to avoid it?
	Reply Like 1
Hanaldo	Hanaldo posted 6 Years Ago Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	1% is low for a gelcoat, typically... Is that what the manufacturers recommend catalysing at?
	Reply Like 1
shakir	s shakir posted 6 Years Ago Post Details
s Group: Forum Members Posts: 3, Visits: 16	+x Hanaldo - 2/12/2018 6:11:16 AM 1% is low for a gelcoat, typically... Is that what the manufacturers recommend catalysing at? If the temperature is too much high on the shop floor like 33~ 35 degree centigrade then 1% we use.Higher percentage will become cause of pin hole Problems
	Reply Like 1
Hanaldo	Hanaldo posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Yes, but gelcoats arent really designed for that, they do have a minimum catalyst ratio as well as a minimum thickness to cure properly regardless of the temperature and it tends to be a fair bit higher than laminating resins. For example the gelcoat I use cant be catalysed less than 1.75%, regardless of temperature. Generally this means you just cant do much when it is too hot, which sucks but its just how it is.
	Reply Like 2