Hi folks,

I've been using the above on my current project (model aircraft) and have been impressed with it's hardness when cured. But I find it's quite thick to brush on and doesn't flow very well, leaving quite an irregular surface .  Is it possible to thin it slightly so that it flattens out better?




Many thanks, Marty

The issue with foam and polyester is down to the styrene melting the foam if its the wrong type.  You can seal the foam with a coat of epoxy or use the right foam.  For example I have recently made some wing mirrors.  I used a non-stable foam and coated it with epoxy.  I took moulds from this in polyester gelcoat.  I then made mouldings in carbon / epoxy from the polyester mould.  I see no reason for concern.    However, if you really want to use epoxy then try putting it on thick and you should be fine as its the surface next to the plug that matters.  Alternatively you can wait for it to start to thicken and then smooth it out as it gels.  Out of interest whats your model?  I'm currently building a gas turbine.

ETA:  Been away anywhere nice?

Hi FLD,

Yeah, the plug is glassed and epoxied (see attached) but another reason for using epoxy is that my workshop is attached to the house and polyester is just so smelly! 

The model is a 1/8th scale of a Westland Wessex Mk1 - 6ft from nose to tail. going for electric on this one but may go turbine on the Mk5 version.

Cheers, Marty