Talk Composites - The Forum for Advanced Composites

residue left in mould

http://www.talkcomposites.com/Topic32362.aspx

By Drew - 3/18/2019 8:32:36 AM

Hi,
I am making flat carbon sheets using EL2 resin with fast hardener and vacuum bagging on a glass mould but I am having a problem with a residue left behind when I release the cured sheet.
I weighed the resin and hardener with digital scales and mixed for at least 1.5 minutes.
room temp was about 17 - 18 deg
mould is waxed with mirror glaze
the residue will wash off with soapy water but I'm sure that this is not normal.
this is my  first time using epoxy and carbon  in a mould but I have a background with GRP and have never had this before.
any advice would be appreciated.
Best Regards,
Drew
By Drew - 3/19/2019 8:41:46 PM

 
Warren (Staff) - 3/18/2019 10:06:45 AM
A slight residue or print through could well be from demoulding slightly too soon.  Especially as you are working below 20C you may well find the resin is curing a bit slower than usual. So ensure you have had a proper cure time before demoulding.

Thanks for the tip Warren.
I have done my second lay up today and have got the room temperature up to 25 deg 
I will break it out in the morning.
Hopefully that will do the trick
Br
Drew.