VIP for a race car?

General Composites Discussions Composites Talk
#1

Hey guys,
We are experiemnting with vacuum infusion like crazy. We are building tons of test panels and we are goign to do some major testing. I will publish the data if I am allowed.

First let me say this. We have plenty of 6k Prepreg sitting in our freezer. But we want to try and do some vacuum infusion to build our next race car.

Here’s what we are trying. Infusing two plies of 6k dry fabric. Then a layer of film adhesive, then Flexcore for the core material, Then film adhesive. THEN XXX

Now, the XXX we are experimenting with different procedures. One thing we are trying is dry fabric then infusing ontop of that.

Then we are trying two layers on infused material which is already hardened and bonding to that.

We are trying very hard to develop a method of vacuum infusion to work for the formula SAE race cars.
We are testing VIP because it is so annoying to build a seal the plugs, then build the female mold, then lay the part up. We do 6 trips to San Clemente to use an Auto clave.

We are trying to maching our foam, female mould, seal it and make the car 100% in house.
Now, our prepreg which was donated is 350degree cure. so this is why we need the heat from the autoclave.

We use foam from Coastal Composites and their high temp foam can’t go over 300.

Any suggestions?

Do you know of a high temp high density foam that we could possibly use, in case we go with the prepreg?

#2

Infusion is fine for race cars if done right. It seems this is for a FSAE team at a school, so it will most likely have a tube frame anyways.
Why wouldn’t you be allowed to post results? It’s not exactly top secret stuff.
Swift is pretty far from your location. There are other places with autoclaves and large ovens.
BTW, it’s Coastal Enterprises. :wink: A 250* prepreg would work with their PBHT.

#3

TET.
our car is NOT a tube frame. The monocoque means the body is the frame.

We have been using two p[lies 6k prepreg. .5in thick flexcore, 2 plies prepreg.

And u are right about Coastal Enterprises. My bad.

Our prepreg is 350* so it seems like none of their foam would work for us.
Do you know of any other relatively inexpensive material that can be machined and used for a female mold and taken up to 350*?

Swift does our autoclave work for free. thats why we have been using them

#4

Ok - bad joke but so CA.
SO are you stuck? I don’t know - but maybe this could be a substitute :

Make a Female Mold.
OK - so THIS IS THE PROBLEM – the temp needed for the pre-preg is melting the foam plug when in the autoclave.
Maybe – stop that!

ALTERNATIVE – SAVE the pre-preg and use some other resin/glass composition for the female mold. (CONCRETE? PLASTER? OTHER?) Probably cheaper than the high temp foams - and quickly available! Then use the — hopefully high temp resins mold for the pre-preg. Just outta the box – may be off base too – but something else to consider.

BTW really - REALLY like the monocoque idea you are working with.
Cheers - Jim

#5

I have been working over 10 hrs a day for the past 3 days but I finally figured out a way to use honeycomb with the infusion method.

Infuse two layers. Then, place a layer of the proper film adhesive, then honeycomb then film adhesive then two dry layers.

Infuse the two dry layers. Then cure the two layers of film adhesive.

Going to perform destructive testing on 4 or 5 panels on Friday. I am crossing my fingers that everything works.

yesterday I helpped a guy infuse a carbon fiber one piece wheel. I can’t believe that it actually worked. Ill post some pictures if he lets me.

#6

Won’t work. How are you curing the film adhesive? Is it compatible with the infusion resin?

It would be interesting to see pics of that wheel. Hopefully it won’t actually be used on anything a person rides in/on!

#7

IT works! The infusion resin is cured for both sides, then the film adhesive is cured.
The film adhesive works as a barrier between the honeycomb and the dry fabric.

I will take pictures and take some time to write a througho demonstration.

The carbon wheels are so damn strong that the machine which does the destructive testing was not able to put enough load on them to crush them.

We are insuing some small scale versions to see if the strength will be there for the infusion method.

#8

What type of orientation should I use for plain weave? 0 and 45?

#9

Is the film adhesive heat set/cured? The real test would to be sanding/peeling off the one side, and see if resin filled the cells!