Spawn Aerodynamics - Bullittes CF build thread.

[37Z]

"One mold provides the exterior contours and the latter the interior contours and structural rigidity. Once both molds are complete the two parts need to be bonded with carbon specific structural adhesive for wet layup, if dry carbon was used you could reintroduce heat and the two pieces would bond together in an autoclave."

Even better, vacuum bagged, pre-preg carbon fiber in a two-piece mold in an autoclave with humidity,temp, and pressure control.

[rufio11]

If you could make a front bumper without the fangs and still have it look stock, Kinda like the Nismo version without the lip, I think that would be welcome with open arms and open wallets.

[njmike]

Originally Posted by CCCLXXZ

I am assuming you have never made a carbon fiber hood before because you have not mentioned making two molds for the hood. One mold provides the exterior contours and the latter the interior contours and structural rigidity. Once both molds are complete the two parts need to be bonded with carbon specific structural adhesive for wet layup, if dry carbon was used you could reintroduce heat and the two pieces would bond together in an autoclave.

Completely untrue. Once a thermoset polymer is cured, it can not be reheated to bond to other matricies.

Read up on thermoset v. thermoplastic polymers. All structural resins are thermosets.

There are specialized adhesives used to bond cured composite components.

[CCCLXXZ]

Originally Posted by njmike

Completely untrue. Once a thermoset polymer is cured, it can not be reheated to bond to other matricies.

Read up on thermoset v. thermoplastic polymers. All structural resins are thermosets.

There are specialized adhesives used to bond cured composite components.

The prepreg is partially cured which means that it is in B-Stage. It can be trimmed, pleated and formed using a knife or a pair of scissors. The prepreg handles very easily and because of its tackiness, it will lay tightly into your mold.* You might still have relief cuts or pleats to contend with just like you would with a dry fabric.*

After placing the layers in the mold, the prepreg must be compressed to allow bonding, to remove any trapped air between the layers and to squeeze out any excess resin. Although there will be very little excess, the resin will naturally become thinner as the temperature is raised and there will be resin flow prior to a full cure of the resin.* **

The needed compression can be accomplished using a press but unless the part is perfectly flat, a press is not an option.* Consequently, the part is generally vacuum bagged.* *

With prepreg fabric, there is a benefit in having plenty of time to build your bag and get the part ready for the oven.* You are not fighting the natural pot life of the resin.* However, the more layers you have laid, the more likely that there will be air trapped between the layers.* You should really have perfected your vacuum bagging technique before laying multiple layers of prepreg for a single curing.

A big advantage of prepregs is that after curing and cooling, additional layers can be laid onto the part without scuffing or additional surface preparation.* Again, up to ¼” can be laid at a single time with the same consideration of not trapping air between layers.

After the layup is complete, the vacuum bag is built and sealed, and you are ready to pull vacuum and begin the heat cycle.* There are 3 recommended cure cycles for Fibre Glast prepregs.* All 3 will produce similar properties.

There is an unconventional new prepreg out that can be stored at room temperature and can be layed up in stages. This is not consistent with traditional thermoset resin prepreg that requires handling and storage at sub temperatures.

[njmike]

Originally Posted by CCCLXXZ

The prepreg is partially cured which means that it is in B-Stage. It can be trimmed, pleated and formed using a knife or a pair of scissors. The prepreg handles very easily and because of its tackiness, it will lay tightly into your mold.* You might still have relief cuts or pleats to contend with just like you would with a dry fabric.*

After placing the layers in the mold, the prepreg must be compressed to allow bonding, to remove any trapped air between the layers and to squeeze out any excess resin. Although there will be very little excess, the resin will naturally become thinner as the temperature is raised and there will be resin flow prior to a full cure of the resin.* **

The needed compression can be accomplished using a press but unless the part is perfectly flat, a press is not an option.* Consequently, the part is generally vacuum bagged.* *

With prepreg fabric, there is a benefit in having plenty of time to build your bag and get the part ready for the oven.* You are not fighting the natural pot life of the resin.* However, the more layers you have laid, the more likely that there will be air trapped between the layers.* You should really have perfected your vacuum bagging technique before laying multiple layers of prepreg for a single curing.

A big advantage of prepregs is that after curing and cooling, additional layers can be laid onto the part without scuffing or additional surface preparation.* Again, up to ¼” can be laid at a single time with the same consideration of not trapping air between layers.

After the layup is complete, the vacuum bag is built and sealed, and you are ready to pull vacuum and begin the heat cycle.* There are 3 recommended cure cycles for Fibre Glast prepregs.* All 3 will produce similar properties.

There is an unconventional new prepreg out that can be stored at room temperature and can be layed up in stages. This is not consistent with traditional thermoset resin prepreg that requires handling and storage at sub temperatures.

Yes, everything you posted is correct. (it should be, it was copy/pasted directly from Fiberglast's site).

About Prepregs - Fibre Glast Developments

your plagiarized work starts about 2/3rds down the page.

Yes, a prepreg system (like any other epoxy resin) allows laying up in multiple stages, provided proper debulking, etc as described in the link, but you're original statement that the OP could layup a hood skin, and the underlaying support separately, then simply clamp them together and place them in a autoclave to bond them is preposterous. Clearly you're misinformed.

There is very limited use of thermoplastic matrices used with carbon fiber, and non of them in a laminated structural part.

Again, read up on thermoplastics vs. thermosets. All epoxies (and poly/vinylesters for that matter) are thermoset resins and once cured, can not be melted and recured.

[SpawnAeroJohn]

What is your solution for storing the molds in your garage to retain proper symmetry and strength without distorting the original mold shape?
Since most of our early molds were small they would be stored on shelves or in storage lockers. Our latest molds have gotten bigger and bigger. Any mold that is practically a simple big shape (hood face, roof panel, etc) has a back brace that we mold into the final layers of the mold which keeps the mold from warping while curing. Once the mold is cured its cured for good and if its kept flat it wont change shapes. We also do not remove any molds until we are sure its fully cured. We don’t quick dry our molds with heat or UV lighting, we just let them sit for at least 48 hrs in room temp. We also use the highest quality resin we can find which has a super low warp or shrinkage rate. Even more so if the mold does not over heat so we do not put on multiple layers at once to prevent that.

Similarly, if you don't have the original parts you are creating... assuming you are making a fiberglass mold, what is your plan if one of the molds break or crack in the future?
We would either buy the part or preferably have a local come down to remold the product. We always would rather create molds of live parts since they are already fitted to the car and have kept shape for some time.

How do you control the humidity and temperature level in your workspace to achieve proper curing as per recommended specs consistent with the resin you use and to prevent the carbon fiber fabric to absorb ambient moisture?
Since most shops do not control humidity only temperature its never a real issue. But we can not control either or so the way we counterattack the "might be problem" is by mixing chemicals to alter the structure of the material yet alter it in a way so it does not change the properties of strength and or shape. We do this by either adding in acetone or other high evaporative substances such as that or other products which if the temperature is over 80 degrees. Those added materials evaporate before anything else gets a chance to. And by that time the parts are already curing. We also change the amount of activator / hardener we put in. If its hotter we put less hardener so it wont affect the shape. If its colder we put more so that the materials don’t separate.

What accommodations have you planned to incorporate the hood mounting hardware, for the hinges and hood latches?
We are still trying to work that out but the best idea so far is to have an outside company create steel plates that will go behind the hardware so that nothing cracks or separates.

I could ask so many more questions.... but I will just continue to watch. My questions are in no form derogatory or demeaning. I am trying to present constructive criticism to address areas where this extreme hobby experiment can go wrong. I hope to buy a few enhancements if all turns out well... I just think a simple dash kit would have been a good place to start and then add one additional product at a time.

If you have any questions, please feel free to contact me as I live very close to you and have created a few carbon pieces for hobby value.

There is a reason why F-1 teams have multi-million dollar budgets, because they work with and use carbon fiber...

And to throw it out and make this my longest post yet, OCC owned a steel manufacturing enterprise before dabbling with motorcycles. And coincidentally those motorcycles were made of 80% steel parts. Never did Paul Sr. design and build a motorcycle in his basement or garage...

And yes I do know that. I also know that its the TV show that got them to where they are today. But I try to personally look past those facts just to boost our confidence. We have never had doubt in ourselves but this just helps.

Thank you for your time - that is all for now,

Nick

And we only know you are trying to help. In no way I thought of this as an ill post. Yes right now we don’t have the best environment but it is a place where we can do our work with great concentration, all the surrounding businesses and neighbors are real happy with our presence as well as the local law enforcement as we are doing some jobs for local police officers, and right now it’s the best place for our position. Like I did say in a few weeks to late summer we will be renting out a 5000 sq ft warehouse in Chicago that a friend of mine / fiberglass supplier is offering us at a very great price. So right now its not the are around us or the are that we are in, it’s the techniques we use to counter all of the “what could be problems” which so far has worked well and we have yet to come across a problem.

Also all our carbon fiber is vacuumed to remove excess materials, thin and lighten them down, and remove any air bubbles / moisture that can ruin the part. That is the one technique that really does effect the overall outcome of every product fiberglass and carbon fiber.

I might be contacting you in the future

[SpawnAeroJohn]

Here are more pictures!

This is yesterday and today combined.

Here is Manny spreading on the gel coat (most of the pictures have him in it, and no he does not do all of the work ha)


The gel coat on the front bumper license plate back.


Starting fiberglass layup


The first 7 coats of fiberglass


Preping the rear bumper for the mold.


And today we pulled the mold for the front bumper (Ill get pics tomorrow) But here is a picture showing we take extra precautions to make sure the panels are not harmed during glassing them. As you can see the bumper is in the same condition as it was prior to laying fiberglass over it.

Tomorrow we will make the first carbon fiber roof, front bumper license back, and a FRP replica of the hood which we will modify for the scoops.

We will also start the fenders, hatch, and the reverse side of the hood for the molds.

10 days to go and allot of work to do

[nogoodname]

doing a good job !!

[Caravanshaka]

Honestly, I think the coolest part about this build is that you are walking us through the steps you are taking to build these parts. We don't just see a picture of the final product and order, we literally get to watch you build them so we can see as close to first-hand as we possibly can without helping you, the quality and craftsmanship that goes into the product.

I will definitely be interested in some of these parts in the end, especially since my car has a black and white theme

[semtex]

Originally Posted by Caravanshaka

Honestly, I think the coolest part about this build is that you are walking us through the steps you are taking to build these parts. We don't just see a picture of the final product and order, we literally get to watch you build them so we can see as close to first-hand as we possibly can without helping you, the quality and craftsmanship that goes into the product.

I will definitely be interested in some of these parts in the end, especially since my car has a black and white theme

I agree. What a refreshing change from the attitude that some companies have. Take SSR, for example. They won't even release offset info because they 'don't want to share their trade secrets with their competitors'. They're a bunch of tossers is what they are. Props to you guys at Spawn Aerodynamics.

[nogoodname]

^ that's the difference between a private shop and a commercial business shop.

+1 to u spawn

[Caravanshaka]

Originally Posted by nogoodname007

^ that's the difference between a private shop and a commercial business shop.

+1 to u spawn

Agreed, it's been the same with berk and their cat-back as well. getting to see the process along with testing has helped spark more interest, as well as more confidence in the consumer. It's a win-win situation for anyone building a quality product. If your product is a piece of crap though, you don't want to be doing this

[SpawnAeroJohn]

Awwwwww shucks!!!

[LiquidZ]

Keep up the great work Spawn!

[nogoodname]

Takes guts to show the process... Nothing to hide.

This reminds of fast food joints. Who knows what happens in the kitchen.