hey guys =]
i didnt want to hijack the other flanging thread but as i mentioned in there i have a mate who prefers not to flange at all if he doesnt have too, majority of his work is hand lay up though… is it mainly for bagging? i will admit about a fair few of my automotive panel moulds like front bars, gaurds etc i didnt flange… i have been told a few reasons for and against, but is it worth flanging every single mould??
flanging vs non flanging???
I find that it always makes life easier if the mould has flanges around the edge of the part because it gives something to allow excess resin and cloth to spill onto, if there isnt a flange and the cloth falls over the edge for whatever reason it will easily lift meaning flaky crappy edges if your not carefull. flanges make bagging easier if your doing that also.
people who do open molded parts like nonflanged molds because they can trim them while the part is green, saving a lot of time. also it saves time on plug/mold building since you do not need to flange. Other than that there is no benifit and is not recommended for any part that gets vacuumed, even if you plan to do a envelope bag on the mold.
even on a open mould you put a flange as it gives stability to mould and avoids twisting.
we would never waste time or materials making a good mould and not put a flange on, not talking of once off or to make a “better plug shape"moulds which will be thrown out after one or two castings.
also my wife builds products and as she says " where will I put the resin container, you expect me to hold it all the time” is another reason all bigger moulds get 120mm to 150mm flanges.
Smart man you married a keeper! I wish my wife had that kind of sensibility. 
yes she is quite educated on composites and I cringe as most men treat her like a fool, meanwhile she knows a lot more than some of the reps we do business with, yet
they treat her like a fool.
…never judge a person by their genitalia! 