Hi Folks,

I'm having my first attempt at making some simple wet lay CF shapes and using a glass sheet bonded to MDF backing as a mould base.

The part is flat 100mm x 50mm and has a 10mm radius on leading edge which has been formed using polyester body filler.

I'm following the how to guides & have coated the mould with 6 layers of Easy lease and brushed on the is EL2 (slow) resin.

Problem is that the resin seems to be repelled from some areas of the mould leaving areas where there is no resin at all!

I tried brushing it back over the uncovered areas but it just keeps opening up again a few minutes after its covered.

I used digital scales to accurately measure resin ratios and am working in clean area at 20 deg ambient temp. 

Any ideas?

Thanks,

David.

That's the release agent. Easylease is a 'high slip' release agent, and it lowers the surface tension to a degree where liquid molecules adhere more to themselves than to the mould surface. 

Hanaldo is spot on again.  EasyLease does tend to cause this effect during wet lay with thinner resins.  Most gelcoats are generally fine but thinner laminating resins can fisheye in this way.

As said, a layer of mould release wax will reduce the "slippy" nature of the surface enough to help resin application. 

If you are stuck in the situation then as the resin begins to thicken and gel then the resin is less likely to fisheye off the surface.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thanks guys,

I tried with the wax & didn't have the "Fisheye" only issue is it has left a cloudy finish to the surface layer.

Any recommendations on how to improve this?

Did you buff the wax off after applying it? 

I did buff it down but only fairly lightly as the directions said to be careful not to remove it completely?

You want to remove it to a degree where you don't see it on the surface any more, it should look like it is gone. But you don't want to buff it so hard that you rub off the release agent. 

You should be able to polish the surface of the part if it has a matt surface from the mould. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant