Just finished my Vacuum bagged Carbon Fiber smooth flow windscreen fairing , using carbon fiber twill fabric and west systems epoxy eliminates most of the bobblehead buffetting yet provides some wind protection, dead zone of air in front of my chest with smooth air flowing overhead
Damn!:eek1 That looks awesome. Well done. Are you gonna be making these for sale? I have no doubt there will be a lot of interest I know I would be interested in one when I get my 990.
I cut down my oem shield like many out there, and it didn't solve the buffeting. Now I just get lots of bugs on my faceshield. How tall are you? Do you find your faceshield is clear of bugs? Are you going to make MORE??
these are difficult, expensive and very time consuming for me to make I gtot all my materials from Aircraft Spruce and Supply, the highly flexible and strong West Systems epoxy is about $50 a quart, takes 1/2 quart each and 1/2 yard of carbon fabric, then theres sandpaper, polyester resin for the mold and vaccuum bagging suppplies, I wasted the first 3 parts to get a decent one, I have about 40 hours and $400 to get to this one, then it takes an entire weekend to vacbag cast and cut and finish it would be nice to sell a few to recoup some of my costs but with the hi quality materials it barley at a profit , especially with all the finish work involved, it is near impossible to get it perfect I can make more so I would sell this one for $190 if anyone is interested it is about 9.5 out of 10 in perfection there are a few tiny bubbles and minor imperfections around the edges but overall very cosmetically acceptable the design is a vast improvement but is not magic , dont expect it to be like riding on a Gold Wing you can cut and lay yours back to see if it works for you if anyone is interested let me know and I can ship it quick and Ill make another
If you think you have a good design and just can't get the manufacturing process to be cost effective, maybe work something out with one of the companies that work with the stuff every day.... CJ Racer carries some pretty trick CF parts and I'd bet he has some contacts in the right places. I used a guy over in Greece (Carbon Aramid Constructions) but I wouldn't think that's the most cost effective solution. Good luck!
thanks but Im not really having production problems I looked over at CJs and see CJ is getting $100 for a pipe guard, there were some fenders and side panels but says out of stock and limited production, put in an order and maybe they will make some. I would bet the reason is the same reason I would not do it, its a lot of work, and effort doesnt matter how pro you are Casting gel coat fiberglass is easy, even castin CF is easy , but casting cosmetically perfect CF in epoxy with a lot of bends is not easy the pipe guard is less than 1/4 of the material with less bends so it would be relatively easy to cast in phenolic heat resistant resin , the tight bends make CF difficult, I have made some pipe guards too, wouldnt mind getting $100 a piece. by price comparison this fairing should be in the $400 range a few people expressed interest so I put out the offer to sell a few, its been all day and not one nibble think I'll edit and change the price or withdraw it it would be a teeny tiny market and it would be easier to make money selling hot dogs its just a fun hobby I have been doing for about 20 years if youve ever done it youd realize whats involved I would think most manufacturers would need to cast in polyester with one layer of carbon and the rest fiberglass backing in order to keep the price in range I could do that too but all carbon with epoxy vacuum bagged is a different species than average run of the mill production pieces
Nice looking screen there!! For the fools like me that might be interested in trying to vac-form something like that, do you have a specific source for info? I know I can google and get hundreds of hits, but was there one (or a few) websites that you found particularly helpful for the process and procedure? Cheers, Greg
Have you looked at vac infusion? That would solve 90% of your problems - and if you went to prepreg it would solve just about all of them. Tooling is specific and youd need an oven to do it tho.
OH yeah ! I am DOING vacuum infusion, its also known as vacuum bagging 6mil layer sealed to the top of the mold with a perforated peel ply and breather cloth and vacuum pump pulling 14hg for 2 hours this is no mickey mouse part it is all aircraft quality prepreg and infusion would be awesome but the cost would be thru the roof next weekend I'll be doing a pipe guard for the RFS using CF and HTR heat resistant resin, the heat sheild works best with even less resin to CF ratio , it will need lots of vacuum clamp the HTR resin is $160 a gallon
I have been using the same west system vacuum bagging instructions since about 1996 http://www.westsystem.com/ss/assets/HowTo-Publications/Vacuum-Bagging-Techniques.pdf I have found one of the most important steps is "wetting out" the fabric it has to be fully wet with all the air squeegeed out without distorting the fabric and with the least amount of resin possible before placing the first ply needs to be layed in with no fabric distortion yet have all the bubbles sqeezed out before the next layer goes in , not an easy task, then each layer needs to go in with no bubbles without distorting the first layer , the other thing is having everything layed out and ready so that the entire mixing, wet out, lay up and applying vacuum clamp happens within 6 minutes
Infusion is where the resin is pulled into the bag after the vacuum has been applied. What you are doing is a vacuum assisted layup. You will never get a perfect face for ornate CF straight out of the mold. It will always require post processing. Shield looks good...
Oh hey thanks, are you making those tall ones ? what process and materials are you using,they look great
Composites is a bit of an art, and it usually takes a lot of time and money before you can make production quality pieces. Most people start out using fiberglass and a simple mold, and then move on to more complex lay-ups, techniques and materials. http://www.cstsales.com/tutorials.html has some nice tutorials to give you an idea of the basics. I used to really enjoy it, but I've got a building alergy to epoxy...
I do. and thanks. Before starting my lighting operation I was an aerospace and automotive composite toolmaker since the late 70's We still do quite a bit of prototype work There are a lot of different ways to skin a cat. Ive developed a process of compression molding that does leave a very good face, however I still struggle with getting a perfect part every time. The naca ducts in that shield are a pain to say the least. One advantage to infusion is that you layout the cloth dry, so you really see what you have, the disadvantage is that it is expensive. The next step up is RTM molding this requires a two sided sealed mold much like the compression process only the resin is injected..This is typ how high end ornate production composites are made. Alu or steel tools. There is nothing wrong with a vacuum assist layup, its time consuming and expensive, then requires secondary ops to finish the part. Its still the way 90% of composite aircraft parts are made, only they use prepreg and dont care about the finish.
thanks for that, I dont feel too bad then that I just get a few small bubbles around the edges can you suggest a better mold release than mguires carnuba ? it releases the part well but seems to interact with the surface of the epoxy,
any of the carnuba waxes should work well. Believe it or not for a very large unmentioned aircraft company the norm was treewax sold for doing wood floors. I still use it if I'm in a pinch. I often use freekote, but that requires an oven. what kind of reaction are you getting? Did you seal the mold surface?
I originally planned to make only one so i didnt even do a gelcoat it seems like the mold always needs a few runs to get conditioned , even after 5 coats and melting a few coats in with a hairdryer if I use PVA it is really hard to release but the surface is more clear, the wax works great but leaves a dull finish that requires wetsanding with 600 and 1000 grit. so I guess it doesnt get any better
It does sound like a mold issue. Using pva is giving you a seal and making a better part. PVA has its own issues and is problematic for most. I think your doing fine..
