The subject regarding pre-forms has been mentioned a couple of times with no response so I thought I would throw it out one more time. Just wondered if anyone here ever had the need to use them or if you have any expertise on the process and the sizing used. I’ve sure experienced difficulty in discovering any useful information on the subject.
Jon
I did some testing at home, but for my curiosity…preform with vacuum and then glue fabrics with glue sprye
There are several companies specialising in preforms. Basicly there are 3 types of binder used commonly:
-stitched. Usually for complicated relatively 2D shaped parts. Like brackets in carbon, stitched on veil. Used in RTM moulds.
-spray glue bonded. A bit “poor mans solution” and not suitable for large scale production
-powder bound gun roving: used a lot for RTM light. Polyester only.
http://youtu.be/QAmsiFUoxYM
http://youtu.be/J2qe8KtY9Bs
http://youtu.be/CUS1rfTcWwQ
http://youtu.be/tGYwOQPnMQg
Hehe, guess who made the mould in the first video (the small boat)
Herman, are you in the video? If yes…do you have the thermoset binder? 
That’s really cool Herman! I’ve watched these videos in the past but had failed to gather some info within, namely the banner that read “CompForm-American GFM”. Did a search and found the company site. There is a video in the site showing their very elaborate pre-form process but still not alot of help. I’m not interested in anything as elaborate as that, but would like to find out, as GAB981 is, as to what the thermoset or uv cured binder is that is shown in the above listed video, and whether it is compatible with epoxy or not. Is this a big secret?
Jon
These binders are soluble in styrene, so mostly targeted to polyester. (basicly the same stuff that holds CSM together)
No, I am not in the video. I am way more handsome… 
What kind of heat gun is that in the video and what kind of blanket was that, that he used to compress the preform before activating the binder with the heat gun?
The heat gun is probably a Leister, but any big-ass heat gun will work.
The fabric is a silicone. heat resistant, and air tight. Keep in mind the fiber is sprayed on a perforated mould/shape, and a vacuum is applied to get some fiber compaction. (which you can see as the silicone fabric is sucked towards the mould)