1. Poor surface gloss
Poor mold finish, surface dust, etc.
Low curing agent content, incomplete curing, low curing degree, not post-cured.
Low ambient temperature, high ambient humidity.
The gel coat layer is not fully cured before demolding.
High filler in gelcoat, low collective resin content.
2. Wrinkles on the surface of the product
Wrinkles for the gelcoat are common diseases, the reason is that the gelcoat for full curing is prematurely covered with resin, and styrene so that part of the gelcoat is dissolved, swelling and wrinkles. The following treatment methods are available:
Check whether the thickness of the gelcoat is in accordance with the specified value (0.3-0.5mm, 400-500 g/m2), if necessary, can be appropriately thickened.
Check the resin performance.
Check the amount of hardener added and the mixing effect.
Check whether the addition of pigment affects the curing of the resin.
Increase the workshop temperature to 18-20℃.
3. Pinholes appear on the surface after curing when small air bubbles lurk in the gel coat. Dust on the surface of the mold can also cause pinholes. Treatment is as follows.
Clean the surface of the mold and remove the dust.
Check the viscosity of the resin, if necessary, use styrene to dilute it again, or reduce the amount of thixotropic agent.
If the mold release agent is not selected properly, it will cause poor wetting and pinholes, and the mold release agent needs to be checked. This does not occur with polyethylene.
Do not mix air when adding hardener and pigment paste.
Check the spraying speed of the gun. If the spraying speed is too high, pinholes will occur.
Check the atomizing pressure and do not make it too high.
Check the resin formula. Too much hardener will cause pre-gel and latent air bubbles.
Check for proper grade and type of methyl ethyl ketone peroxide or cyclohexanone peroxide.
