Hello all,

              I am currently having a problem with my Xpreg XC110 prepreg. In my last test the prepreg did not cure and was still  gooey once the cure cycle was complete. My oven, which is home is set up with a proper PID controller complete with the thermo coupling. Its shows to have reached the temperatures that are recommended for the XC110 system. My mold is a CNC'ed piece of aluminum 2" thick. The mold itself is 20" x 46" x 2" With basically the back and sides of a guitar cnc'ed into it. When I did the trial run once it had soaked for an hour at the higher temp I lifted the oven off the mold so it could room cool. So, what would be my problem? 
A. I should have left the oven over the part to let it slow cool
B. the aluminum is taking to long to reach temperature
C. the oven isn't actually reaching the temperature the thermo coupling says it is. 
Any other ideas on what it may be would be of great help.

Also, unlike the video my surface finish is almost like dry carbon, there is no clear looking finish on it at all. Does the Paper side of the pre-preg go down first or the plastic side? or does it matter? and could it be the either over cooked or under cooked problem that could have also caused that?  Any help would be greatly appreciated. Thanks!

JC

Thank You Gentlemen for the replies, you have confirmed my suspicions. My oven is crude at best but I thought it seemed to work well. The thermo-couple is mounted in the dead center of the over, running parallel underneath the surface. once the oven is lowered down over the mould it is approximately 1" away from the surface of the carbon. However, I plan now to run test on the system to see what the surface temperature is at various points on the mould and at different times during the cure cycle. Don't make to much fun of my oven, I can't afford one large enough to get a 150 lb. mould in at this point. I have the oven on a wench system that I raise and lower  over the moulds, which are mounted to there own rolling table. I polished the moulds to a high gloss finish after these pic were taken, but I believe the "print through" , which is exactly what I am getting, is due to my cure temps of the mould. As you can see, the mould is directly laying on a wood table. Would you suggest raising the mould up so there is an air gap underneath so that the mould itself would heat more evenly? I greatly appreciate your comments and suggestions. Just as a starting point would anyone
have a suggestion for a modified cure cycle to fit my circumstance? Thanks again!!



JC