So, I tried laying up my first part at the weekend, and got nowhere fast. lots of slow, unidentifiable leaks. I tried again and again, and couldn’t get my bagging film to seal on the glass.
In these times, if you’re lucky enough to have a mentor (Warren, Carbon Copies Ltd), that’s when you ring them. His first suggestion is that laminated, toughened glass can be porous. So, I liberated a mirror and did a small lay-up on that. Then I started struggling with the final seam on the bag. There’s always a bit of slack, and it ends up as a crease (in which vacuum escapes). So, he suggested not going into a corner (which was my default behaviour, not design), but to finish on the seam nearest you in the middle, and to put a bit of extra gum-tape on the bagging film where you know it will meet the gum tape you’ve laid down. Ta-daa – where the seam appears, you already have tape, and can treat it just like a pleat.
So, I pulled full vacuum, and left it overnight. it’s still there today. I suspect I have one more leak in my system to eradicate. I patched it last night, and removed the patch today. if the vacuum drops then I know this is an issue, and have a solution to fettle it.
I feel quite pleased – Warren did say to me “well, you’re at the point when people give up, plough through”. That I did.