Hi all,
I’ve seen that release fabric and release film are not always put on layers in the same order: sometimes the sequence is
1- layup-release fabric-release film- bleeeder/breather
and sometimes
2- layup-release film-release fabric- bleeder/breather.
I can understand ther first setup , but I wonder the reason of the second (the most application used hand layup and vacuum).
Why are you using two releases? You either use a fabric (eg nylon, poly) or a film (perforated with holes).
Layup - Release Film/Fabric - Bleeder Breather - Vacuum Film
If you are using peelply you still use a release film(usually perferated). then after the release film you have the breather material. Then the bag.
That is all assuming you are talking about vag bagging and not infusion
Yes, I’m talking about wet hand layup &vac-bagg and not infusion
I would use:
Nevertheless I wonder if make it sense to use a sequence like perforated-peelply-bleeder-vac film
If you put the peelply between two layers of perferated film, you would just be waisting the peelply and the second release film in my oppinion as it would not acheive anything. Could actually cause further problems
#2 makes no sense. Peelply (release fabric) and then film. I have used Film, then fabric, but no breather, so i get airflow over my prepreg for compaction, but NOT have a rough surface finish. (breather leaves more of a lumpy surface.)
Riff42,
what I understand from you post is : layup(prepreg)-release film- (release ?) fabric-vac bag ?
If it’s so, what happens if , in your stacking sequence, you remove the fabric on top the film ? Did yo get the airflow for campaction as well ? ( using release film with larger density of holes, for example )
layup(prepreg)-> peel ply-> release film(if you want)-> air weave (or breather cloth, whatever you want to call it)-> bag
For non-prepreg I am going to use:
lay up,
nylon peel ply,
perforated release ply,
breather fabric.
I so far am not a fan of plastic release ply against the laminate… gets ugly wrinkle patterns on the backside of the laminate.
The way I use it is
lay up
peel ply (only if I want to bond sth later or to achieve a better looking surface on the back of the laminate- otherwise u can skip it)
perforated release ply (after the peel ply to help me remove easier the wasted soaked with resin materials or after the layup to prevent breather from sticking to the laminate)
Breather fabric
Bag
I see different approaches, but ,at the end, I conclude that:
Thank you all 
im having problems with my slow cure epoxy.i use perf-breather-bag.the harder i have recently switched to has to be cured at a minimum of 140f.at room temp it will take a day and a half to cure.so what i have been doing is letting the bagged parts sit in room temp for a few hours before putting them in the oven.this doesnt seam to help.the parts are still loosing to much resin.so i have heard that the teflon coated nylon peal ply will not allow so much resin to soak through into the breather.anyone have any other tricks to stop the resin loss during the curing cycle?
what type of release film are you using? there are many different size preferations and spacing. I would suggest using a p3 release film as that only has pinprick size holes, this will help from pulling too much resin from the laminate.
i buy the perforated from fiberglass supply.they only stock one type.it is .015 size holes on 1/4 inch centers.that is a pretty small hole.so is there smaller perforated than this?
thats p3. what viscosity resin are you using? you resin viscosity is probably droping very low under your curing temp. let the part cure in ambient temp, then post cure.
yea,thats what i was thinking too.im just not sure how long to let it go in room temp.if i have to go more than 5 hrs it really cuts down on my production.im not sure what the viscosity of the resin is.its plasco high impact clear with the medium hardener.
Perforated film controls resin drainage. Get a lower perforated film, for instance P31, but there are many more.
Another option is to wait longer for the resin to raise in viscosity, or to lower the vacuum.