+x

 

Classicarbon - 3/3/2020 7:58:59 PM

Made mould,dry nicely but still can see through gelcoat.I mean it not went completely " milky". I used 3 layers.One for coupling coat and 2 after.
Should I apply another layer of fiberglass?
picture was taken  before full cure.

+x

 

Hanaldo - 3/4/2020 2:55:54 AM

+x

 

Classicarbon - 3/3/2020 7:58:59 PM

Made mould,dry nicely but still can see through gelcoat.I mean it not went completely " milky". I used 3 layers.One for coupling coat and 2 after.
Should I apply another layer of fiberglass?
picture was taken  before full cure.

You need a minimum of 4 layers of 450g CSM when using tooling resin, NOT including the coupling coat. Hopefully the layers you have already done will still cure properly, as tooling resin actually needs to bake itself with the heat it generates from its exotherm during cure to achieve full mechanical properties. 

For a one off the mould will probably be ok, so just sand the surface with 80 grit before adding another 2 layers of 450g. 

+x

 

Matt (Staff) - 3/4/2020 8:18:09 AM

Yes, as Hanaldo has said you need 4 layers, 2 layers of 450g mat (even laid up resin rich, as the Uni-Mould system is) is still only around 2mm, a fibreglass mould of this size would need to be *at least* 4mm thick. Again, to reiterate Hanaldo's comments, the Uni-Mould system relies on its own exotherm to cure properly and this exotherm is only reached when there is adequate laminate thickness, which is 4 layers of 450, applied 'resin rich'.

Was there any reason why you only went with 2 layers of 450g?  - I'm just trying to get a handle on whether the instruction to use 4 layers needs to be clearer in our instructions for the Uni-Mould system.

+x

 

Hanaldo - 3/4/2020 2:55:54 AM

+x

 

Classicarbon - 3/3/2020 7:58:59 PM

Made mould,dry nicely but still can see through gelcoat.I mean it not went completely " milky". I used 3 layers.One for coupling coat and 2 after.
Should I apply another layer of fiberglass?
picture was taken  before full cure.

You need a minimum of 4 layers of 450g CSM when using tooling resin, NOT including the coupling coat. Hopefully the layers you have already done will still cure properly, as tooling resin actually needs to bake itself with the heat it generates from its exotherm during cure to achieve full mechanical properties. 

For a one off the mould will probably be ok, so just sand the surface with 80 grit before adding another 2 layers of 450g. 

+x

 

Classicarbon - 3/6/2020 9:17:38 AM

+x

 

Hanaldo - 3/4/2020 2:55:54 AM

+x

 

Classicarbon - 3/3/2020 7:58:59 PM

Made mould,dry nicely but still can see through gelcoat.I mean it not went completely " milky". I used 3 layers.One for coupling coat and 2 after.
Should I apply another layer of fiberglass?
picture was taken  before full cure.

You need a minimum of 4 layers of 450g CSM when using tooling resin, NOT including the coupling coat. Hopefully the layers you have already done will still cure properly, as tooling resin actually needs to bake itself with the heat it generates from its exotherm during cure to achieve full mechanical properties. 

For a one off the mould will probably be ok, so just sand the surface with 80 grit before adding another 2 layers of 450g. 

What can you suggest for mould reinforcment?
After all layers I was planning to fibreglass in wooden frame in to mould stiffen mould and be able to stand mould.upside down.I was thinking about some kind of ribs to make reinforcment (what kind of material can be used?).