Type of Fiberglass?

[Agewon]

Just to preface this question; I would be unable to complete this project if it were not for this forum. Thank you.

Now for the question. i am making a cooler liner and have made one of two layers of 6 ounce cloth that i feel is a little flimsy. Of course the insulation will help stiffen it up, but i am afraid that it will cause it to distort too. If you look at my posthttp://boatdesign.net/forums/showthread.php?t=18873, you will have an idea of what i am making and the strength needed. I am trying to stay away from woven due to my inexperience, and cost and am unable to glass in "stringers" due to clearance. Is there any way to strengthen the one i have already made? Adding heavy cloth panels to the shell? I plan on making a few of these, so i am prepared to purchase new fiberglass if need be. thanks again.