Should I use both male / female formers when vacuum bagging?

[flanajb]

I am about to embark on laminating some tight curves and I was wondering whether I could achieve a tighter curve with less risk of tensile failure on the outer face if I use a 2 piece mold and then vacuum bag, or will the vacuum bag provide enough support on the outer face so that I will only need a single former ?

Thanks

 

[Peter Sefton]

You may well achieve a better tighter curve with less risk if you do use a male and female former but we usually only use one half. But I always recommend using a 3mm MDF cover sheet to spread the pressure evenly (I know in theory a vacuum applies the pressure evenly but in practice it struggles to pull down to a totally flat surface). It is even better if the MDF has a painted face to prevent it from sticking to the veneered surface