Hi new to CF, done a few bits but just keep getting surface bubbles…
so…
i’ve got some tape, vaccuming polyethene, fibre sheet + a peel ply.
just dont know what to do with it all???
Also how do i pay for the pay per view classroom???
thanks 
Are you doing hand lay ups or using what process to get air pockets?
i guess you are vacuum bagging? personally, and a couple of other members in here, doing vac.bagging without a surface coat, will give you porosity. transparent polyester gelcoat, or some other stuff people use in here (duracote whats its name), and then layup on that, will cure your problems.
Another question that comes to mind is are the bubbles in the unfinished part, or after you apply a clearcoat? We’ve seen some problems with vendors with outgassing in the finish when they don’t prep right…
-G-
Well, to start your tests (do small bits yeah, not a large mold)…
If you are doing wet layup and bagging:
brush down your resin
add your fabic, add more resin, make sure you got the fabric saturated.
do that for all your layers.
add a layer of perforated release, seal the edges of the release with tape.
add layer of bleeder (glass cloth, or airweave/breather)
tape and seal vac. bag, of course adding your vac tube AWAY from your resin (else, it gets sucked in your tube, and in the pump)
vacuum on.
wait.
tons of videos on youtube showing this, and VARTM.
First I would recommend buying the FiberglassSite.com cd-rom and reading up on it for $2. Next if you are able take much time reading up on this forum. Most everything is covered on the forums here, BUT it is scattered about so the search feature is the best way to find what you need.
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[/ul]Also there are many different ways to “lay up” a composite part.
There is pre-impregnated carbon fiber and fiberglass that comes on a roll already saturated with the resin. The resin is heat activated. It is also room temperature activated if your not careful. This requires a seperate freezer to hold the roll of cloth that comes about 50" length wise. It also requires an oven or autoclave to bake the laminate. Which in turn requires a mold that can withstand the temperatures of the oven.
Then there is open wet lay up, which uses no vacuum. For this to work you have to have a glue like surface sprayed onto the mold surface. Since spray glue is not going to work for this, people use clear polyester gel coats or clear polyester coat. This is the only way to prevent air pockets between the mold surface and the first layer of laminate. Read up on wet lay ups and open mold lay ups to know what products are used and how to use them.
Then there is vacuum bagging a wet lay up. Resin is brushed or sprayed into the mold, the first layer of carbon fiber or fiberglass is then layed down gently into the mold followed by more layers and more resin. Then a peel ply is layed down, followed by a perforated release ply, followed by breather cloth. All this is placed into a sealed vacuum bag. To do this method using polyester or MEKP activated resins is going to be hard to do because most times the tech(us or you) won’t be able to get all the plies and breather placed down before the resin gets to B-stage ( the stage where resin gels); and by then it is a junk laminate/part. Unless you only activate the resin with 1% or less MEKP catalyst… or if you work in a freezing cold shop you could use 2% MEKP and have a go at it. If you would like to see a good video on vacuum bagging check out YouTube and search for “Carbon Fiber Cello” part1 - part2 two videos.
With all resin systems temperature is the big work time factor. The hotter the ambient air, the faster you have to work OR buy the right resin for the temperature you work in. Currently I work in 95F so polyester or MEKP activated resins don’t work well for me. I use epoxy … it has a longer “pot life”. All resins have their uses and learning how to choose the right resin for you is the key to your success.
There are three more ways to make a composite part: VARTM, RTM, and RTM lite. You won’t really want to mess with these until you have been doing composites for at least 6 months using other methods.
The best way to learn about laying up composites is to practice. Make small test parts, this way you waste little resin and materials. Try making a few small carbon fiber/fiberglass plates. There are several ways to do it. Again the search feature on this forum. What this will do is familiarize you with resins and how they react and how you react to them. It’s also good practice.
If you plan on vacuum bagging you will need sticky bag tape, try the yellow tape from fiberglasssupply.com or fiberlay.com. or some other supplier. the yellow is called AT-199 or AT-200, can’t recall at the moment.
As for a vacuum bag if you are bagging complex shaped parts in the future, not now …please not now… try Stetchlon 800 vacuum bag. Airtech.com and fiberglassSupply.com sell it. I have found it to be very good and easier to work with than other types of plastic.
Materials are chosen based on the part you are making, what the intended use of the part is, and what environment is the part going to be used in. Once you narrow your materials down to that level then you can choose from a host of brands and types of products suited to your needs.