Crestamould® Gelcoat 15PA(B) is a superior performance vinylester brush tooling gelcoat for making moulds designed to have a long service lifetime and retain high gloss levels after multiple pulls. It is easy to apply and achieves good coverage.
There is no gassing of the gelcoat ensuring a very low porosity surface. It cures with a standard MEKP catalyst. Crestamould Gelcoat 15PA (B) has excellent resistance to fibre print through when used with Crestamould VE679PA skincoat, Crestamould RTR4010PA or Crestamould Resin 474PA.
Features and Benefits
• Vinyl ester base resin
• Matched tooling system
• Excellent chemical and heat resistance
• Good impact resistance
• Excellent surface finish and can be polished to high gloss
• Reduces reinforcement print-through
Gel Time and Backup Time
Catalyst level and temperature will influence the gel time. The product only requires the addition of
catalyst to start curing. We recommend the use of a 50% MEKP (type Butanox® M-50) which should be
added at 2% in the gelcoat.
For optimum life, a mould constructed using Crestamould® Gelcoat 15PA (B) should be fully cured before
being put into use. This can be achieved by placing the mould in an oven at 40°C for 30 hours. If this is
not practical, the mould should be left in warm conditions (>20°C) for 2-3 weeks prior to use. Where a
mould is likely to experience severe conditions (e.g. due to high exotherm temperatures within backing
laminates), it should be post cured at an elevated temperature. Contact our Technical Service department
for further advice
Mould Release System
When a new mould is manufactured, traces of residual monomer remain within the tooling gelcoat.
Although post curing at 80°C will reduce this to an insignificant level, exposing a new mould to this
temperature is not always practical or desirable. The first release from a new mould is, therefore, likely to
be the most difficult, particularly if a mould which is not post cured is subjected to elevated temperatures
during its initial use. These temperatures could arise from the exotherm of the laminate contained
within the mould, or from the mould itself being passed through a heated area during use. The following
procedure was developed to combat release problems on new moulds manufactured and cured at
workshop temperature. It demonstrates an excellent release performance on new moulds and is equally
effective on moulds of any age:
1. Before first use, allow the mould to mature for a minimum of 7 days at 18°C or above.
2. Clean the mould thoroughly with a polyester mould cleaner.
3. Apply a polyester mould sealer according to manufacturer’s instructions.
4. Apply a semi-permanent release agent according to manufacturer’s instructions.
5. Optional – apply one coat of a hard wax such as Mirrorglaze. This will reduce any tendency to de-
wet or pre-release when the mould is used.
6. After the first release, use a masking tape test to check that the release agent remains on the
7. If so, apply one coat of semi-permanent or hard wax. If not, repeat steps 2 to 4.
8. Continue as step 6 until the release performance becomes predictable and easy then re-apply
one coat of release agent as and when required.