Sorry for digging up this old thread. What Alex said about the laminate taking bits off glass off, this has happened to me using a semi permanent release. I released both the glass (toughened) and an aluminium sheet that I used for the B side. The prepreg gripped really hard onto the glass, it ripped bits of glass off and left a print of resin on the surface which is going to take hours to scrape off. As for the other side, the aluminium released fine, but it left an even silvery residue over the entire surface (?).

Hi,

From what I can see in the above pics it looks as if you have had a bit of a "sticker".

For the laminate to pull up chunks of glass like that you would need a fair bit of adhesion and if you have adhesion between the part and the tool then this could only be caused by poor application, contamination or incorrect choice of release agent!

The Aluminium will also form an immediate oxide when in contact with air, I get the feeling this is whats been taken off with the laminate at time of release...

Kev.

When i did mine i sandwiched between two sheets of glass which had been thoroughly cleaned, and dried and then i waxed them with a good number of layers both panels of glass both sides and all edges, and also then used PVA release. I would be 98% certain that it was completely covered, and it wasn't just in a specific area where it peeled up, but all over and random. It didn't phase me too much, that sheet i now use as my cars ice/snow scraper in a morning 

I have made several flat sheets successfully by using a piece of 4mm float glass stuck down to a piece of 18mm MDF with double sided tape, the MDF stops the glass from shattering.  I used Meguiars Mirror Glaze No 8 wax for a release which seems to work fine, I applied about 10 layers of it to the glass before using it.

If you are concerned about distortion on thin glass you can use an envelope bag so you have equal vacuum either side .

Chris

I did an infusion once on a mirror and everything went perfect after 6 coats of  Meguiars Hi-Temp Mouldrelease.

It sure looks like you didn't have a good release present. I have used Easy Lease and ChemTrend. They seem to work and are applied the same.

Are you following directions? You must let it start to flash and then polish and wait 15 minutes. Not 5 or 10 but 15 in room temperature.

Do 5 or 6 coats and then wait a full hour. Not 45 or 50 minutes but a full hour. This is a test I do on every mold I prepare and I think it is a must.

To check to see how active your surface is. Take a 5 inch strip of good masking tape and stick it down before you apply your 1st release agent. Now pull it off straight up and note how much tack you have, or how active the surface is. Now apply your layers of release and when done do the tape test again. It should practically fall off. If it still sticks pretty good you have a problem.  

The only problem with this is that even the bagging tacky tape will hardly stick either.(I know that failed leak tests are sometimes caused by this)

So here is another thing I do on every mold.

I first apply the release all over the mold. When done I now take scotch brite fine and scuff the entire molds perimeter. In other words about in one inch from the edge of the mold. I now apply 2 layers of normal composite wax on the places that I scotch brited. (do a tape active test and see how inferior wax is to chemical release)

Now the tacky tape sticks like baby poo to a blanket! It also aids in taping down you stack layers. I never have leaks anymore.

Hope this helps.

Fred

I've been using glass that's bonded to a table since 1988 and use PVA release agent applied with a sponge and in all that time I've never had a panel stick. Resins vary from Polyester to Epoxy, vinylesters and even phenolics. The glass is 5mm normal stuff from the glaziers. I was making 50 panels a month for flight cases and never had a reject.