99% of the time when you get a leak in the bag its usually not the bag but the sealant tape. Best thing to do is to look closely at your sealant tape from the side view, you will see little gaps where there overlaps and its not sticking well. Also make sure that where your sealant stick there is...
you may even be able to buy a mat-fish gelcoat or additive, but no too sure because I have never needed it. You could call some suppliers to get there opinion
you can use a mat-finish semi permanent release such as frekote. but the real question is do you really even need gelcoat? if you infuse correctly your part can have a pitfree surface with no gelcoat and also be mat-finsihed from the release. but maybe it needs to be a certain color or have a...
another point to add is you must have a perfect vacuum with absolutly no leaks. You ahould be able to cut your vacuum source off before in infusing for atleast 15-30 minutes and see absolutly no drop in vac. level. One peelply strand can ruin this. Do not attempt to infuse unless you have no drop!
It sounds like your draining your part because either your laminate or infusion mesh is connected to your vacuum source. You should have at least 3-6" of space between where your laminate ends and your vacuum source is, the only thing connected the two should be peel ply. You also want to keep...
I would try the same panel on a different surface such as tempered glass. See if you get the same amount of warpage. Or try a lower post cure temp for longer time if possible(check manufacturer). That should tell you if it is warping at higher temps.
