Fiberglass replacement panels

[tdave00]

I am gonna start building a truck this summer and I want to keep it as light as possible. Has anyone used fiberglass body parts and if so, where is the best place to order them from?

Thanks

[crazy longhorn]

www.usbodysource.com

[tdave00]

Thanks,

Has anyone on the board used any of these parts?

[PanelDeland]

I haven't used them but it's my understanding that they are race type parts.This generally means that they are not structurally designed for street use.I "think" they are quite thin and lightweight.From previous discussions the concensus is that if the fibreglas panels were built strong enough for street use they would weigh as much or more than steel.As I stated this is just what i remember from previous discussion.

[crazy longhorn]

They sell both "race weight" & street weight parts.....i have not used them , so I send this thread TTT....crazyL

[Mondo]

truckinfx.com

tilt front end might be nice

[Mordachai]

I have heard that the parts from USBody are really well built.

If you are building this truck to be 'light weight' are you intending to make a track/race vehicle, or do you want to build a streeter?
The two would be very different builds.


There is alot to consider for either build, as removing the metal body panels will remove alot of the structure of the truck(front fenders hold the Rad. support, etc)

When removing these parts, you need to replace them with some sort of metal structure. Usually for race, it'd be chrome moly steel. Usually in a race vehicle, the vehicle itself is rock solid, and the body panels simply cover the metal and give it some aerodynamics (how much in a p/u I don't know)

As said above, if using it for street use, the panels would have to be quite a bit thicker/heavier to resist the normal abuse of a DD. for instance in race weight a simple rock tossed up by another car can cause a nasty crack in that light fiberglass. And that race weight glass will tend to vibrate like crazy at cruising speed, unless it has really well designed bracing supporting the backside. And if you do use the heavier weight panels, you still need to add some steel bracing/supports. So either way, while removing the steel body parts, you will need to add steel to make up for the lost rigidity.


A good trade-off is to get a urethane glass front, instead of a resin glass front. The urethane is much more flexible and forgiving when it comes to the little bumps etc that a streeter will see.

Either way, going to glass panels is a big job, don't let anybody tell you not to do it....


I made my own front end, like a goof, out of urethane. But I might very well use the USbody bedsides if I don't make my own molds. I might even leave it steel, not sure yet.
Just to throw this around, my new front end is around 70-90 pounds lighter than the steel hood alone! I added about 100-175# of steel in the rad support braces(top and angled bottom) and front end hinge, etc. So even adding steel, I probably dropped about 250# of weight off the front. I did not take it to the scales to weigh it before I stripped it down, but I could feel the difference in driving. And my truck still had the heater assembly,radio and amps, big bench seat, power steering(instead of manual r&p for race) All things that a real track ride wouldn't have. So my truck is obviously not a race car by any means, but is simply race inspired!!

[tdave00]

Sorry, been sick for a few days. Thanks for the detailed info.

I was thinking of lightweight fiberglass for one reason - gas mileage. I just want a very nice DD that I can afford to drive . If I need to stick with a steel cab for safety then I will. I will probably give the guys at usbodysource a call to inquire about the structural integrity of their non-race parts.

I have been doing some research for the last few weeks on carbon fiber as well. I am gonna give it a shot at fabricating a frame out of carbon fiber if it makes enough difference weight wise.

[Mordachai]

My truck will be a steel cab when I'm done(give me a chance to keep my welding skills current), and probably glass bedsides with wood bed, and steel gate. the whole front clip is glass, and the inner wheelwells will be glass too front and back.

Too bad you're in TN, or I'd say I can work with you to make the parts.

Just from experience, the thought of a carbon fiber frame is cost prohibitive unless you are building a true out and out race car. To have CF function properly and give all the strength it should really be press molded. Vacuum bagging is pretty good, but the true way to reduce light it to reduce the overall mass, and only press molding CF will make it VERY lightweight and Stronger than steel. If you are just vacuum bagging it, and leaving alot of resin in the fiber, then you might as well use traditional glass fiber.

I'm not trying to tell you that you can't, but the cost to finished effect is incredibly high on a CF frame. (Just think each part of a pressed CF frame needs two molds that the CF and resin can be sandwiched in. And those molds need to be constructed to apply a very even force over the whole surface of the mold while being pressed. A vacuum bagged part still needs one mold per part, so there's a ton of work in having it done right.)

I think that instead of trying to reduce weight with a CF frame, doing simpler things to reduce overall weight are better suited to a DD. ( smaller gas tank, run flat tires and no spare,lighter seats, etc) If you were really inclined to reduce frame weight, I'd build a chassis out of chrome moly tube steel with machined Al parts on it....


I'd ask USbody if they can produce a part for you with urethane resin(instead of polyester resin). Urethane will allow the body panels to take quite a substantial hit, before it breaks, and then it will often just flex and crack. The polyester will shatter upon impact, and even small flexes can make it crack. I have seen poorly mounted glass panels crack from flexing while driving because they were not properly mounted. MY urethane front has actually seen a few bumps, and one or two bangs, but not a crack on it! (It is also around 1/4" thick on all the edges and outermost surfaces. The only thinner areas are the hood and fendersides, and even those have strips running across them that add alot of rigidity.

[tdave00]

Thanks. That's good info to have. A carbon fiber frame is probably a little ambitious , but I was thinking of building a small mold from a piece of the frame and testing it. Since the frame rails are basically 3 sided with 2 90 degree bends I was thinking of making a mold around the frame and then creating a plug out of some semi stiff foam. From there I could lay the carbon fiber into the mold and then the preformed foam. A piece of preformed tubing could then be centered on top of the foam and clamped from the top of the tubing to the bottom of the mold, which should essentially press it into place???

That should be interesting to find out what type of resin they use for their body panels.

[Mordachai]

yeah, that urethane casting foam could work for that, but you'd have to be sure to use the high density casting foam(16# per Cu. Ft.) That HD Foam can actually be cast and then milled, it's really tough stuff. But while it is rigid and hard it is also kind of brittle.
The other thing if using that foam for a plug would be that it is porous, so you would have to fill and seal it to prevent your resin from bonding to it.
Also make sure you use a casting foam that can withstand the temps of a kicking resin. If it melts, it's a world of a mess.
Also, if you simply pipe clamp it, I'd use a clamp every 8-12 inches starting from the middle and working out to the ends. Be sure to liberally apply release on the mold and clamps and anything else that the resin might stick to.

Also, instead of using that casting foam, you could just as easily make a fiberglass plug for the inside.

One of the other things that help give carbon fiber it's inherit strength is the shape of the finished part. A tube, or cylinder is the strongest 'profile' that you can get, and that's why Cf parts are often round in profile.
CF tubing is kind of easy to make, Take a piece of polished SS(I always use SS, easy to work, stays rust free...) and wrap 3-5 layers of masking tape on it. you can also wrap it with newspaper and then 1 layer of tape. Then make two molds that cover the wrapped pipe. Once those molds have cured, you can take the tape off of the tubing(or use a fresh piece) and then make your CF part, by applying pva and release to the pipe, applying resin and wrapping the tube with CF 'tape', 2-3 layers of the 'tape' with the seams covered by the middle of the next layer. Once you've got them on,cover it with your release fabric and press the two outer molds on the pipe and wait for the cure.

That's a really simple explanation, but should work, unless I forgot about an important step.

[Mordachai]

here's a well known sports car that utilizes Cf fro many components, including the chassis!

http://www.compositesworld.com/hpc/issues/2005/July/923

I think this illustrates the R&D/Engineering that goes into a project like a CF frame/chassis...

As well as considering things like stress points and the orientation of the fibers, and things such as heat factors from your engine/tranny(CF composites do not like heat at all)

Read that article, it should give ya good insight to what you might or might not consider doing on your vehicle.


I'd go with steel frame, using USbody's Glass cab(race weight is like 50-100#!!!) and building a full CM roll cage. Glass panels and Aluminum parts(even the engine block) would be a great way to reduce weight and maintain structural rigidity as well as safety.

BTW- many race cars use composites not only for weight savings, but in the case of an accident they are great for helping to distribute the force of impact in event of a crash. Have you ever seen a race car's panels 'explode' on impact? if so, then they were doing their job!

take a look through composite world's sourcebook pages, there's a ton of helpful info there...