I made a pattern (1.63 x1.45 meter) already by CNC machine, then fill the surface with auto body filler. After sanding the cured filler up to 600 grit. Apply gelcoat and sand again for moulding later, i found there is the changing in dimension.
How can i do to keep the plug at the correct dimension?
Many thank for your help
For starters, before you CNC make sure to post cure all your materials fully, then CNC. Afterwards, be sure to keep the temp and humidity constant. Fluctuating temps & humidity will make your plug unstable dimensionally.
Many thank hojo.
The change in dimesion i recommended is the thickness of applied filler and gelcoat on surface. Especially in some corner.
Make sure you use the same material as the surface to do repairs. For example, if you are using an epoxy paste, then repair it with the same epoxy paste. Cure it fully before you sand it. Using body fillers, you have different CTE than your other materials, so the defect can come back if the temperature gets hot.
Thank hojo again
I used polyester base body filler and polyester gelcoat.