How to remove the layering line in resin layer casting?
To be honest, it is difficult to completely remove layering lines. Because polyester resin is not cured in one go, it is difficult to maintain consistency in all factors. This is like repairing car paint, just trying to be as close as possible, but not completely eliminating color differences.
For example, when making a resin river table, some seemingly inexpensive epoxy resin adhesives cannot be poured with a thick layer of resin at once (such as 50mm), because polyester resin can crack due to excessive shrinkage. Usually, the second layer is poured when the first layer of epoxy resin adhesive has just hardened and is still sticky, which may result in a less obvious boundary. If it is necessary to wait until the first layer is completely cured before pouring the next layer, the epoxy resin curing interface needs to be polished and cleaned, but it cannot guarantee the complete removal of the layering line.
Since you already care about the layering line, it is impossible to reduce resin shrinkage and prevent cracking by adding inert fillers such as calcium carbonate or aluminum hydroxide, in order to achieve one-time pouring. So you need to choose some high-performance thick layer casting resins, these specially modified polyester resins have lower heat release curves and better toughness. Within the set thickness range, there is generally no problem of overheating, deformation, or discoloration, but the unit price of resin is relatively higher, after all, you get what you pay for.
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