I’m thinking that, to make some of my small projects easier, having prepreg fiberglass, cf, and kevlar might be a good thing for me…so now I’m wondering how to go about making it!
So far, all I’ve been able to come up with would be to infuse individual sheets of the reinforcement on a plate of glass, and as soon as the resin is infused, stick it in the freezer to retard the curing process.
Thoughts? Ideas?
I and a lot of other people, especially here in Indianapolis do something like that.I call it “Wet-Preg”. We don’t infuse the resin in though. We lay a sheet of visquine (plastic sheet) on the bench and then pour some resin on the plastic and spread it around evenly with a bondo spreader or a decal “squeegee”.Do not use too much resin here; only a thin film is required. Carefully laying the fabric on to the small quantity of resin, the fabric is straightened out and smoothed down on the plastic. More resin is then poured on the fabric and spread it out. The correct quantity is when no resin is removed from the fabric with the spreader. I use a specific amount of resin per square inch. For instance, for 5.7oz 3K 2x2 carbon I use .085grams of resin (not including hardener)per square inch of fabric. Once the resin is spread on the fabric, another sheet of visquine is spread out on top of the fabric and it can then be placed in the freezer. I usually impregnate two layers at once as I usually laminate two layers at a time.
When you want to use it, bring it out of the freezer, let it thaw for a couple of minutes, lay your templates on it, cut it out and remove the lower piece of plastic and lay it in the mould with the other piece of plastic still attached. When happy with the position, peel off the top piece of plastic. Bag in the usual way. The vacuum ensures full distribution of the resin thoughout the fabric. I do virtually every part like this. I find it the best way to ensure the correct resin/fabric ratio. An excess of resin is often the cause of poor surface finish, blisters, breakouts etc because the cannot escape especially if the breather is clogged with resin.
Last sentence is supposed to say “because the air cannot escape”.