Hmmm might have to cave and buy a vaccuum pump and the four extra materials…I suppose it would save epoxy in the long run.
After looking at pumps again and realizing how expensive they are I have a new idea. I’m not sure if you’ve heard of Air Lift, its a tool used to put the coolant system into a vacuum, it replaces all the air in the system with coolant, and the device is essentially a venturi pipe that uses compressed air to generate vacuum. I think the same principle could be used to create a vacuum pump that doesn’t cost an arm and a leg. I found this one for $50 roughly.
http://www.veneersupplies.com/products/Vac-Pro-Venturi-Vacuum-Generator.html#
I was reading that you utilize different amounts of vacuum for the finish you want, hopefully this will work well. I might order it for my next project, for now I’ll finish these by hand.
At this point I wouldn’t worry too much about it. It is really only advantagous when you initially lay down the material as it will give you good compaction and even resin dispersion.
Have you been giving it heat after application in an effort to kick off the epoxy faster? I ask because when the temperature is rising it can cause air bubbles to expand and get trapped underneath. Also, too much hardener won’t let the epoxy ‘gas off’ enough before it hardens, it doesnt look like that is the case though.
Here is what I would do:
-Sand those pieces and try to get the bubbles exposed/sanded out, be careful not to sand into the material.
-Give it a good acetone wipe down
-Use a hairdryer or heat gun and warm up the part BEFORE applying another layer of epoxy (warm to the touch, about 140 degrees)
-Now when you apply the epoxy it will start to thin on the warm surface but immediatly start to cool causing the air to contract and essentially suck the resin into the air pockets. Also, any air that does get trapped will have an easier time getting out because the epoxy is thinner.
Hope that helps!
I haven’t been using heat at all, I just kept layering on the epoxy and after 4-5 coats it seems to even out, heating up the surface is a great idea though, I’ll definitely give that a shot! Where did you work? Or what do you do? You seem to be pretty experienced in epoxy use
Oh well I can’t tell you that 
Just kidding
I am actually fairly new to the world (I’m only 23). I have worked in composite repair for Boeing for the last two years. I Have learned A LOT from the old timers there and have done a lot of research on my own looking to get into similar projects as yourself. In addition, I have a material science degree in composites, which isn’t nearly as impressive as it sounds haha.
I’m 23 as well! Fresh outta the womb! That’s pretty crazy, its one of those jobs that you have to wonder how you get into. I tried to get Ocarbon to shoot me some pointers, but he got pretty offended, other than that just reading online, but the things you’ve mentioned are things I haven’t come across yet. Do you a lot of vacuum bagging? After seeing that venturi tool I’m thinking about trying out a vacuum bagging technique with it. $50 and an existing air compressor vs a $2000 pump
I could see why haha he is very proud of his work. And yeah it was kind of a weird thing I fell into, but I love it.
Everything we do is vacuum bagged and cured. Can’t take risks when you’re working on airplanes.
We use venturi pumps all the time. Nothing special. Can’t be lugging around big vacuum pumps around the factory.
Glad to know airplanes still have some quality in them. Any specific brand of venturi that you would recommend over another? That one I linked above was the first one I’ve seen aside from the airlift kit.
^Those are the ones that we primarily use. one end connects to compressed air and the other with a quick disconnect with an air line to run into the vacuum bag. There are a lot of different ways you can do it and that one you linked to will work just fine also.
y
Yeah I would like just a plain vanilla vacuum pump, keep it simple and easy. One thing I did find interesting is that you can either lay I the epoxy heavy and let the vacuum even it out, or I saw another kit where the epoxy comes in completely separate on another hose, as air is sucked out, epoxy is sucked in, wonder how well that works though. It’s crazy how many different techniques there are for such a simple task
Yeah resin infusion really only has an advantage when you’re doing large parts like boat hulls or making big molds when laying all the resin/fabric by hand will be extremely time consuming. You just get it all layed up and under vacuum and essentially suck the resin out of a giant bucket. Saves a lot of time. But is a little complecated to set up as you have to make sure you’re resin lines are spaced correctly to allow even distribution. I learned about it in school but have never done it. 90% of the stuff we do is with pre impregnated materials so it’s just sand out damage, lay up, vacuum and cure (in a nutshell)
Pre preg seems like the smarter way to go but I couldn’t find any that was red it was only in black.
Do you ever think of making carbon fiber body panels for your car? Sounds like you have access to everything you need. Make a hood, fenders, trunk, cut out like 100 lbs of weight.
Prepreg wouldn’t have given you the look you wanted. Wet layup is the way to go for cosmetic stuff.
And as much as I’d love to do that, it wouldn’t be worth the work that would have to into it. Not to mention I don’t have near the space or cash to take that on haha.
You ever watched the “/drive inside koenigsegg” videos? It’s a series on youtube. I guess to you it might be just ordinary work, but I was watching then make wheels, intake plumbing manifolds, all out of pre preg and Cnc aluminum molds, man it’s crazy, makes me wish I worked there, I would design all the crazy things.
I think he said a 19x10 wheel weighed in at like 13 lbs, my 19x8.5’s weight double that!
There a company in Australia who makes carbon fiber wheels for the b6/b7, carbon revolution, I spoke to them a while back but they wanted 25k for a set of wheels, the owner did mention they were working on an oem line of wheels not Audi specific but more or less hinting that they are expanding and with a bigger factory they would be able to have higher output and decreased cost to the customer. Maybe one day they will cost what forged wheels cost.
Damn man, they quoted you $25k? I actually emailed them last week regarding a set of wheels. They said their 19x8.5, they don’t make 18s, set would weigh in at 15.7lbs per wheel and the total cost with titanium bolts plus shipping would be $15,700. The best part was when he mentioned they couldn’t warranty them because they only have a short list if cars they’re approved for. Pretty sick though.
http://tapatalk.imageshack.com/v2/14/08/27/a31f7432f5782f67c0497aa97c9bdfd3.jpg
I’m looking to buy a set of ga3r forgelines now. 18x18.5s are 17.7lbs per wheel. That’s the lightest I can find other than the carbon revolution wheels.
By the way that YouTube series is awesome.
Nope you were completely right, I just looked at the email. $15k for a set of four, and 15 lbs a corner. its light…but I don’t think it warrants that much money lol. Wasn’t APR coming out with a set of forged wheels that were 19x8.5 @ 17 lbs? Probably like $4k but forged wheels aren’t expensive. Never saw more of those.
Yeah the “/drive inside” series are awesome, especially that koenigsegg segment, they really put a lot of work into it. The owner seems like a really nice guy.
HERE IS MORE INFO FROM CARBONREVOLUTION:
Hello Martin,
You are right in thinking that 15lbs is “heavy” for a 19x8.5 carbon fiber wheel. We have deliberately over engineered the wheel. Having said that you will be hard pressed to find any wheel approaching 15lbs in a 19x8.5. I don’t know of any.
There are other benefits to a Carbon Revolution wheel as well. The NVH goes down. Carbon fiber resonates at a different frequency than aluminum and our frequency tests prove that carbon is quieter.
<image001.jpg>
The CR-9 is definitely not the final design. But it is the only design at the moment.
In terms of axle load, I’m sure you know that each vehicle has a rated maximum axle load. GVWR. You will find this on a sticker inside the door, typically by the tire pressures, for a given axle load.
The appropriate wheel design load (DL) is GVWR/2. The DL is the basic input for validation testing.
In the USA there is no legal requirement for wheels. Wheels are not DOT approved or regulated by any body.
SAE does publish recommended testing and validation requirements for wheels.
SAE J2530 is a recommended standard. If a wheel is tested to these standards then the wheel may be marked with SAE J2530 and you know the part has met minimum requirement for the standard.
SAE J2530 includes:
• Cornering fatigue test to a bending moment calculated using DL.
• Lateral 13deg impact. To an energy level calculated using DL.
• Radial fatigue to 1.5 million cycles at a wheel load calculated using DL.
Once passed SAE will issue a testing certificate and the back of the wheel will be stamped with SAEJ2530 and the rated load.
In Germany wheels are regulated by a government body, the German equivalent of US DOT is called the FKT. The FKT publishes the rules and the TÜV executes the test. If passed you are issued a registration number for the part and you can put it on road in Germany.
For aftermarket wheels the standard is very similar to J2530 except that the bending moment calculation for cornering fatigue uses 0.9 coefficient of friction vs. 0.7 for US DOT SAE.
The lateral impact and radial impact are the same.
For some special cases TÜV will recommend a torsional fatigue test if the wheel looks suspect.
JASO is yet another certification for Japan. Again the tests are virtually identical to the SAE J2530.
Carbon Revolution is ISO certified and as such we have many procedures that must be followed. One of these is our internal requirements for release of a part. Currently our internal requirements are much more extensive than SAE2530 and are more aligned with the major OEM vehicle manufacturers.
Part of the mystery of why aftermarket wheels are lighter than OEM is the testing that must be passed to release it. For example in the aftermarket there is no radial impact requirement for the part or full vehicle crash requirement. An OEM part must pass a wheel radial impact test which is very aggressive and drives a lot of weight into the barrel and spoke. Many aftermarket wheels fail this test.
OEM’s must also pass full vehicle crash test and the wheel is a critical load path.
At Carbon Revolution we pass the radial impact test and have completed full vehicle frontal NCAP crash tests with our aftermarket CR-9 and we performed better than the OEM wheel!
As a side note at Carbon Revolution we have an and AND philosophy to testing, not an and OR philosophy.
Per the standards you would typically submit a new part to each test. This is OR testing.
Carbon Revolution uses one wheel to complete multiple test.
For example we will use one wheel to complete the full cornering fatigue, then use the same wheel for radial fatigue and then complete the lateral impact.
The aftermarket aluminum wheel company will submit a fresh new part for impact and the CR-9 has completed two fatigue lives already.
So in our development we ISO certified the CR-9 to the initial target vehicle set for Porsche, Audi R8, Lamborghini Gallardo etc… The front axle of the mid/rear engine platforms is lighter than the A4 front engine. So our smaller width wheels have not completed the testing for the higher axle loads.
I know that is a long explanation but I hope it helps you understand the next thing I write.
We have not encountered the maximum wheel load of our CR-9 because a test rig doesn’t exist to measure that amount of force. I’m sure we could destroy it if we crashed into a solid cube of concrete at ridiculous speeds, but who wants to do that?
However, we have destroyed Porsche 911’s in the process of trying to cause critical failure in our wheels.
Hope this helps.
Please let me know if you have any other questions or want to put in an order.
My reply:
Yeah material construction was something he dictated strongly on in our emails too but I look at cost to performance ratio.
And for 15k, as cool as those wheels are you aren’t going to get the performance gains of -500 lbs. with 15k I would do a whole vrt build or buy a another car or take 3 vacations, or get a blown up s4, fix it jhm supercharge it and still have enough to buy dinner for my date and I
Yeah I’ve seen that video. Pretty wild stuff. And that’s a little more extreme than the stuff we do, but I would love to do it!
I would never run them on the street though, especially in our heavy AWD cars. Imagine hitting a big pothole in those, it would just crack it most likely. But if you can afford to own and drive a koenigsegg, then you can probably afford to replace a $3500 wheel. Haha
And I know they extensively test them like they said in the e-mail, but I really would not want to be the one to find out. These are track only wheels as far as I am concerned haha.