I'm new to this whole composites thing and have started pulling parts from my first mould. It was made using the EC gel coat and I sanded down to 1500 grit. As the finish isn't important I didn't go down the polishing route on the plug or the flanges.

Hi

Did you put the same release coats on the flanges? If not that is your problem. I use a different release agent that I think is similar to EC ez lease. This is what I do. I apply the release agent on the whole mold and flanges as instructions. I do a masking tape test on the surface of the mold to check and see how active the surface is. By that I mean, how easily does the tape come off in comparison to an untreated surface. Do the same on the flanges. If it comes off very easy you are good to go.

One problem I had was that the release I use is so slick that the bagging tape would not stick very well.(note this is not EC ez lease) So the solution for me was that I took 400 grit sand paper and scuffed the outer inch of the flange where the bagging tape would get applied. (in essence I removed most of the release) I then applied release paste wax on this area as well as half way in on the flange to give a better barrier. Now I can hardly remove the bagging tape which is OK because I don't get any leaks anymore.

Another tip I have learned. Once you are all bagged up and you are about to infuse. I put my mold in the heat box I have and get things real warm. I then pull it out and go over the bagging tape seams and boy does that stuff stick when warm. I now infuse.

This tip might help you guys who are still having trouble getting a perfectly sealed bag. 

Hope this helps.

Fred   

Hi Fred

On a non-polished mould I use 10-12 coats of easylease.  I find the surface just eats it up!  If you polish the surface then 5-6 coats is enough.

Wow 12 coats!?!?!   Okay I'll give that a try 

Yeah, bit extreme but mouldings just drop out of the mould that requred a bit of a pull previously!  Should sort your problem out.

Hi Andrew

I infused 2 molds for my airplane panels. You can see the finished panels in the projects section.

I slit the gum tape very thin and then put that in between my mold surfaces that get clamped together to act as a seal. (I did have channels in the flanges for this though.) You may be able to use something like this. 

Even a coat of wax release over the release couldn't hurt if your mold is rough.

Fred

silicone sealer on the parting flanges is great, you can also wipe off excess if it enters on to the mould surface quite easily, would sort your problem out

Well, I did another layup this weekend. I put a further 8 coats of EC Easy lease on the mould. It released much easier and the resin on the flanges scraped off very easily. 

Great news!  Glad its worked for you.