Hey People,,

Here's a quick one thats hopefully straightforward?

My problem is, I am making a  plug and getting ready to take the mould. The plug is pretty much a rectangular cube which I'm gonna do in 2 sections, 3 sides of the box per mould.

Now to make the mould I've stuck on some corrugated card to act as flanges that block off the parts I do not want to use yet. So the question is, how do i stop gelcoat getting between the card and the plug? There's very little room to use modeling clay as it will get in the way of the defined corner.. Do I pull the card away a little and then fill the gap with clay, just behind the corner?

Or do  I use nothing at all and hold the card in place (its stuck on with double sided tape, i'd just be holding it to stop it flexing too much) whilst applying the gelcoat, using any lines created as guide lines when I trim the part??

I can post any pics if needed, just let me know!

Thanks for your help!

Rob