This is the extention of the FAQs page where I go into more detail, philosophy, and humor on the various subjects in the FAQs.
Fiberglass is a "composite material" (two or more dissimilar materials mixed to provide a part with the best characteristics of each) and consists of fibers captured in a plastic resin matrix. The resin is liquid in raw form and catalyzed to harden and hold the fibers into the orientations that give the final parts their strength and stability of shape.
My fabricators use standard benzoil peroxide catalyzed polyester resin systems with S-glass fiberglass. This is the most cost effective system for automotive applications.
Other resin systems (vinylester, epoxy) and other fibers are available. However, they add significantly to the cost.
Here's a little philosophy about alternative fibers (Carbon fiber, Kevlar, etc.): If you have a specific need for such materials (maybe you are building a Formula One car or an airplane), you know what you are doing, and you know exactly the benefits of certain materials in certain applications, alternative fibers can be great. However, if you want them because you think they are fashionable, I'm happy to help you waste your money. I can do it, but it will cost you.
Carbon fiber is a lot stronger than fiberglass and can be used to make some extraordinarily lightweight parts. However, to fully realize the difference you need to use an advanced resin system and to autoclave (cure under heat and pressure) the part. This will increase the cost by a factor of at least ten.
For a given weight, raw carbon fabric is about twice as strong as S-glass. Theoretically, you could make a part half as heavy. However, the dry fabric is only a portion of the weight of a final part. Even if you could acheive 50/50 resin to fiber ratio (a very good ratio) cutting the weight of the fiber in half will only reduce the weight of the part by 25%. Plus, for simple panels the thickness of the part adds a great deal of stiffness. With less fiber, you have less thickness and have to compensate by capturing layers of some core material between layers of fiber, thus negating some or all of your weight savings.
Carbon is only slightly tougher than fiberglass, so don't think you can run your carbon fiber airdam into a curb without damage.
Starting to get the picture?
Ditto all these problems when you are talking about Kevlar. PLUS, Kevlar fibers are so resistant to cutting that drilling holes in them or trimming them will require special tools. Heaven help you if you ever sand through the gelcoat and into the fibers. They, "fuzz" and cannot be sanded off. You have to bury them under bondo...there goes your weight savings.
Yes, Kevlar is a lot tougher than fiberglass, but again don't think you will eliminate collision damage. The fibers may survive an impact that would shatter fiberglass, but many times the damage to the plastic resin results in a bunch of crunched up plastic held together by some really expensive fibers!
How about thinner parts for racing?
It seems to me that 3 oz (weight of dry fabric per square foot) is about the lightest I like. This translates to 1/8 to 5/32-inch (0.125-0.156) thickness (rough guess). My preference is for a little thicker glass. 4.5 oz seems to work out well. That results in 5/32 to 3/16 (0.156-0.1875, again rough guess). The parts will be easier to work with and more stable when mounted. They also won’t require so many fasteners to pin it in place.
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Crating and Shipping
Shipping fiberglass IS a pain. Trying to ship it for a resonable price is a bigger one. Trying to properly package it for shipping at a reasonable price adds even more brain damage. All these costs have to be paid by someone.
If the customer expects the supplier to remain in business, then he can also expect to pay these costs...one way or another...either directly or in the form of very high prices. Side note: Just for comparison sake have you ever asked other fiberglass companies what they charge for shipping similar items? Keep in mind that (I believe) a lot of their fiberglass stuff is pre-boxed.
However, I am not insensitive to the cost of crating and shipping, even though the customer pays for it, for two very big reasons. 1) It is a deterrent to the purchase. There are some guys who will buy the stuff no matter what the price or the shipping cost. However, for the majority of us (I'm in the same boat myself), it is an issue.
Obviously, as the seller I want to give the customer as many reasons to purchase as I can, but I also want to remove as many deterrents, too. I'm in the business of selling the parts. The more I sell the better. If I sell a lot, once in a while I can buy the wife a steak instead of feeding her peanut butter sandwiches. 2) Any money you spend on shipping and crating (Which I make NOTHING on, BTW. More on that later) is money you don't have available to spend buying parts from me.
The downside of shipping fiberglass is that it occupies a lot of volume. This means that you need big boxes and that they can't be shipped via UPS. Motor freight is the only practical alternative, and on items that occupy a lot of volume they charge for "dimensional weight," which is a fancy way of saying they are charging you for the volume rather than weight.
You can't blame the carrier, as the trucks are made to carry a certain amount of weight. When you ship something very large that doesn't weigh much (and therefore is mostly air) you displace other revenue generating cargo (i.e., heavy stuff) from the truck. WRT the boxes: When you ship small items (e.g., mechanical parts for cars) you can simply purchase boxes at a reasonable price from any packaging supplier.
I don't have that luxury. For big stuff you have to have boxes made. This costs a lot of money, but the setup costs more. In the amount of volume that I ship (two or three kits a month if I'm lucky...you can see why I'm not getting rich) it doesn't make sense to have this done and suffer the big hit on setup charge or the inventory cost of stocking (ordering AND storing) a bunch of huge boxes.
For a while, I was making my own boxes. It took probably twenty or thirty hours to get "proficient" at it. I say that in quotes because it is still a huge pain. Fortunately, I have made a couple of serendipitous discoveries that help me as well as the customer.
First, I am now scrounging bumper cover cartons from the local body shops (which explains why your box may say "Porsche" or "Subaru" on the side). Most of my fender kits will fit in these pretty nicely if I take the time to organize and nest the parts properly (an artform unto itself, I might add). If a hood is included I sometimes have to do it differently or ship it separately.
These boxes hold up very well to the rigors of motor freight, provided you don't put too much weight in them, and you pad the contents properly so the parts don't poke or rub holes in the box. You also don't want the parts to rub each other.
Even though the boxes now only cost me an occasional six pack, I still have costs and have to charge a nominal crating fee for the time required to go get them, wear and tear on the company vehicle (87 Toyota pickup...I told you I am not getting rich ), and the brain damage of solving the packing puzzle. I also have to purchase and maintain tape guns, tape, banding tools, and banding materials.
Remember, even though this is your hobby, it is the way I feed myself. I have to make money commensurate to the time I expend...that's the way we all get paid at our jobs. That notwithstanding, the cost is a lot less than it would be otherwise.
On the really big stuff (a complete VR kit for example) I still use a professional crating service to build wooden crates. I pass the cost along to the customer with no markup. This is in spite of the fact that I have to supervise the crating and ultimately spend almost as much of my time in the process as the crating guys.
Before you ask: Yes I have tried to build the wooden crates myself, and no, I cannot do it any more economically than the professionals can.
On the shipping: If from the above discussion you now have the idea that crating is a pain, you should try to ship the stuff! It's not much an issue on the smaller items (hoods, fender kits) but on a VR crate where the whole thing is 3x6x7 feet high and weighs three hundred pounds, how do you get it in the back of the truck? You have to have a forklift which has to be fed (cost of purchase, fuel, maintenance...just got through replacing the fuel pump at the cost of four man-hours and a couple hundred bucks).
I no longer have to shop all the carriers, fill out a bunch of BS paperwork, etc, thanks to my second discovery: Freightquote.com. Given origin, destination and the nature of the item to be shipped, they give you quotes via their website that allow you to pick the best price for the speed of shipping that you desire. This has cut the shipping cost in half!
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