$5000 budget Mustang

[preston]

>now carbon fiber, to do it the right way, not so much.

CAn you expound ? I have heard that

1) CF is more delicate when handling and cutting
2) it tends to curl up at the edges while curing, especially in mold less construction.

Why else would it be more difficult to work with ? You don't have to vacuum bag it except to cure problem #2. I'd be interested in your experiences.

[jackfrost]

>now carbon fiber, to do it the right way, not so much.

CAn you expound ? I have heard that

1) CF is more delicate when handling and cutting
2) it tends to curl up at the edges while curing, especially in mold less construction.

Why else would it be more difficult to work with ? You don't have to vacuum bag it except to cure problem #2. I'd be interested in your experiences.

ok, well, I must admit I've never used CF. but I did stay at a Holiday Inn Express last night.

here's what I've gathered:

- the dry fabric itself is very hard to deal with. you need to tape everywhere you cut so the fabric doesn't fray
- FG can use poly resin versus CF must use epoxy resin. epoxy is actually better, but harder to deal with
- IMO, to do CF right is to vacuum bag it. otherwise you've just got a fiberglass part that has a pretty black pattern. that means extra equipment and more work
- it's a lot more expensive, which makes screw-ups expensive

[claytonisbob]

Well, if you want to make something out of carbon fiber and you're going to paint it, I'd imagine aligning the weave isn't as critical. Many CF hoods and other parts are fiberglass reinforced, so essentially they use the CF as decoration. To make a CF part truly light weight requires more than just brushing on resin and adding layers like we'd do with fiberglass... It can be done, but a lot of the weight would be because of excess resin.

Aren't production CF parts made of that impregnated cloth that has the resin in it or something, reducing the amount of resin needed?

[preston]

Yes, high quality CF is made with pre-preg which has the resin already impregnated in it with the correct amount. However to cure it requires an autoclave which is an oven that also creates atmospheric pressure, so it is out of reach for most peopl especially on automotive scale parts. Even a small autoclave is probably a bit spendy. I believe parts going in the autoclave still require some bagging or absoprtion ply too, so its not as easy as just laying it down.

[Bryce]

I am a test/design engineer for a aerospace company. i have done the composite layup classes so I know how they are built. This way I know how to design something from CF that can be manufactured.

We use prepreg and dry cloth. But we vaccuum bag all parts in an autoclave. The resin cures around 300F. The aligning of weave is to ensure a uniform stiffness across a part that is larger than the width of a roll of CF.

If you want to know something specific ask me.

[Ron S]

Its all mute for us regular guys any way, to build a one off part in carbon would cost more then I'd be willing to pay. A buddy gave me a roll of glass matting, so I shouldn't have more then $150 in the thing.

Got most of the sculpting done, have to refit it to the car again, prime it a couple more times, and start spraying gelcoat, and laying fiberglass. I'll let you know how bad it is. Ron

[FirstGenZq8]

that steel part looks great! how much does it weigh? how much weight can you hope to drop w/ a fiberglass version?

[Ron S]

I knew the bumper was just going to be a plug for the fiberglass mold, so I built it out of metal out of my scrap barrel. Its just tacked together, so I really can't use this as a finished part. The bumper probably weighs between 15 - 20 lbs. I would think the glass part will be half that.

[Dan S.]

Dayum! That looks awesome.

[John Wright]

Dayum! That looks awesome.

+1 great job...."AGAIN!", Ron. You just keep on hitting the big home runs. Can't wait to see the finished deal w/ splitter and all attached.

[Ron S]

Yeah, well the fiberglass part isn't made yet. The jury is still out on the homerun, it may end up being a strike out. Ron

[Bryce]

How many layers of fiberglass are you going to use? I would guess with 2 layers that bumpers weighs in at 5-7 lbs. Unless you use too much resin.

[CruizinKev]

looks awesome!!!

[Ron S]

I will probably use 2 layers for the part, and 10 or so to make the mold.

[fordsbyjay]

So did you start with the original bumper and add too it or build the whole thing from scratch? It was kind of to tell from the previous page pictures.

[CruizinKev]

like a glove

[Ron S]

Yes, the top is a cut down peice of the original front bumper off the car. Seems kind of boring without the splitter and strut rods. Still have to finish the ends to fit the car,but it is pretty close.

[Zanie]

I’m nostalgic and like all the old muscle car styling. When you first talked about changing the bumper, my first reaction was: NOOOOO! I love the old Shelby bumper with the chunk missing! I thought: you can’t do better than the tough guy look of the Shelby bumper……or so I thought
But once again, you’ve somehow improved that car.
That looks really cool, so far. I can’t wait to see the finished product.


Your project thread is one of my favorites on the site, and one of a handful of reasons I go to the Motor State Challenge.

[Bjkadron]

I can hardly wait to see it with the splitter and the strut rods!! Looks Mean! And not cookie-cutter like a shelby style! Even though they do look nice.

[jackfrost]

nice work so far Ron!

have you thought about how you're going to attach the FG bumper? you might need to fab some brackets while you're at it