Design Donor and Tools of the Trade
From The Scratch-Built Hot Rod
Chapter 1: Design, Donor and Tools of the Trade
Nearly every hot rod starts with a source of inspiration and motivation. It may have been a car you saw in your youth. It may be a car you spot while cruising the interstate. Or, it may be the car pictured on that weathered page from Street Rodder Magazine you have tacked above your work bench. It's not necessarily a car you want to "clone" or replicate or re-create in exact detail. Rather, it's the car that gets your creative juices flowing and drives you forward to design something entirely new and unique. Something you can call your own.
The source of motivation for the sedan delivery project came from a fairly unlikely place: a cartoon. It was the yellow sedan drawing used as a logo for the Goodguys car club. While the completed car shown in this book shares very little with that Goodguys image, that was never the purpose. The cartoon served instead as a way of getting motivated each day for the work that lay ahead. It created the "itch" that just had to be scratched. It set in motion the entire process of planning, designing, building and finishing the hot rod shown in the following chapters.
No matter where your particular inspiration and motivation might come from, the big question is: how do you convert what you see in your mind's eye, into a full-size, roadworthy automobile?
Putting it on paper
A good way to move forward with your inspiration or motivation is to begin collecting as many pictures or illustrations as you can of the car or concept you have in mind. Photos 1-2 through 1-4 show just a few of the sedans and sedan deliveries that caught my eye.
Normally a project design will begin with a series of sketches. But don't panic. This does not mean you need to be some sort of artistic genius with a gift for drawing cars in order to accomplish this part of the task. As you can see from the accompanying photos, the drawings used for this project were crude, at best. There is no need for a highly-stylized piece of art. What you are after is a rather simple side profile of the car - a silhouette of the car as it sits directly in front of you.
If you are comfortable around computers, there are a number of good graphics programs than can be of great help while doing your sketches. Photoshop was used extensively during the design of this project but there are other good programs as well, including the free "Paint" program that comes with many computers. Again, neither a computer nor software is necessary to create your sketches. A tablet of graph paper and a few sharp pencils will do the trick almost as well, but software does make the job easier and quicker. So, if you are handy on the computer and you can get access to Photoshop or an equivalent program, by all means use those tools.
Sketching the body
For the sedan delivery project, the design work began with scanning a side-view shot of a sedan, such as the one shown in Photo 1-4, into the computer. Then, using the lasso tool in Photoshop, the wheels and tires were separated from the car, hiding them on separate layers of the drawing. The eraser tool was used to eliminate any extraneous lines and background from the photo or illustration. This leaves a layer containing only the basic body.
Next, the ruler tool in Photoshop was used to measure the length of the body. This measurement can then be used to create a scale between the drawing and the full-size car we want to build. For example, if the photo or illustration on your screen is 1 foot long and the full-size body is going to be 6 feet long, the scale will be 1:6. This scale can then be used to start seeing how your finished car will actually look in real life. What you need is at least one fixed element of your drawing that is created and always maintained at that 1:6 scale (or whatever scale you determine for your car).
The "fixed element" used for this design was the tire size. To create tires in Photoshop you can just use ordinary circles, which the program can easily create to any size you want. If you want to use 32" tires on the rear of your finished car, for example, you know that your Photoshop "tires" must be 5.33" in diameter on screen (32" divided by 6, because of the 1:6 scale). If you want to use smaller tires on the front of your car, then do the same calculation to permanently fix the size of your front tires.
Once you have created these circles to the correct scale and put each of them on a different layer in Photoshop, you can move them into the approximate position they should be in relation to the body. This will give you a very good first impression of how your finished car is going to appear.
Your design may look out of proportion or downright awful at first, but Photoshop can remedy many problems. By using the scale, rotate, skew and distort tools, you can adjust the height and length of the car, as well as alter the size and shape of other critical components, such as the windows and the roof height. You can even alter the angles of the car, making it more wedge-shaped or more rectangular by using the skew and distort tools.
|Using Photoshop, the body is continually massaged until you find the exact right combination of elements that give your design the character and look you want, while remaining in correct proportion to the wheels, the one fixed-size element of the car. Remember that by knowing the tires are correctly scaled to "real life" tires, and always keeping those tires that exact same size, the rest of the car (length, height, rake etc.) can be manipulated until it all looks like it's in correct proportion (Photo 1-5). The next step is to dummy up a correctly-sized engine and transmission for your drawing. In this case, a simple trip out to the shop produced the basic measurements for the height, length and width that were needed. Using Photoshop, you can then make a crude drawing of the engine shape and the transmission shape, both scaled to correct size. The engine and transmission drawings can then be placed on separate layers in Photoshop, so that you can move them and place them at will while you adjust such things as the cowl height, grill shell position and windshield angle (Photo 1-6).|
|When you are happy with the Photoshop sketch on screen, it is time to transfer your dream car from the computer to a usable drawing outside of the computer. Here is how that can be done. First, print out the simple side-view sketch that you developed earlier (Photo 1-7). Then measure this sketch to make sure it coincides with the measurements shown by the Photoshop ruler tool. This is necessary because occasionally printer software will not print to the exact size shown on the Photoshop screen. If yours does not print correctly, you'll have to make some slight adjustments to your on-screen sketch using the scale tool until it prints out correctly.|
Assuming the sketch prints out correctly, you next need to "graph" it. In other words, you want your sketched car to show up as if it were drawn on a piece of graph paper (I use the graph paper style with 1/4" squares). To do this, put a piece of graph paper in your scanner and scan it into Photoshop. Then, put that image onto a separate layer of your drawing, placed "under" the layer containing your car's image. What you should see on your screen is the drawing of the car superimposed over the graph paper. You then use the scale tool to resize the graph paper image until it fits on the graph paper to the scale you want to use.
For this project, we will scale up the drawing so that each 1/4" x 1/4" square on the graph paper represents a 2"x 2" square in real life. So, assuming that you want your car body to be 6 feet (or 72") long, the full-size drawing of the car would cover a total of 36 squares - each square being 2" x 2". Thus, on your Photoshop drawing, you want to enlarge or shrink the graph paper image until the body covers exactly 36 squares of the graph paper lengthwise. (Note: be sure you manipulate the size of the graph paper image and not your car body image.) As long as you keep the aspect ratio 1:1 while you do this manipulation, the height of the graph paper will turn out exactly proportional to the width.
When you are done, print it out and you should have a drawing looking something like the one shown in Photo 1-8. As you can see, this a fairly simple drawing and you can achieve something quite comparable with just graph paper and a pencil if you are not a big fan of computers.
Sketching the frame
We will return to this scaled drawing of the body and use it at the beginning of our chapter on body fabrication. At this juncture, we can put the body design work aside and turn our attention to the frame and chassis.
|Once again in Photoshop, you can now use the body silhouette, engine drawing and wheel placement to determine your frame length, your wheelbase and your rear frame kick-up or "Z". Don't worry if your hand sketches or Photoshop frame are an inch or so too long or too short; this can easily be accommodated later. You can just factor a couple of extra inches of wiggle room into the design at this juncture, knowing that you'll be adjusting things slightly as the actual build progresses. What you should end up with is a very simple drawing of the frame like the one shown in Photo 1-9. Next, you need to determine the frame width and the location of your suspension mounts. The front suspension mounts are particularly critical in this particular design because of the Ford Twin I-Beams being used. These axles require special attention in order to get the front end geometry correct. The mounts are also a critical factor in determining the width we must make the frame.|
|No matter what suspension you are using, it is a good idea to determine at this point exactly how and where it will mount to the frame, and include those mounts on your sketch. For those of you who might consider the twin I-beam suspension, the drawings and sketches used for this build have been included (Photos 1-10 to 1-13). It should be noted that twin I-beams can be mounted either under the frame, as was done with the roadster project, or they can be mounted over the frame, as we'll be doing with the sedan delivery. This creates an "underslung" chassis and puts the car closer to the ground. But be aware, the underslung chassis also creates challenges for achieving full suspension travel. It should also be noted that the mounting point (or pivot point) for each of the two I-beam axles is critical, both in terms of height and distance from each other. As you can see in the sketches, in order for the axle king pins to line up parallel to each other, and for the wheels to be correctly spaced, the I-beams must overlap one another at exactly the right position and angle. The most reliable way to do this is to set the distance between the mounting points (pivot points) at the exact distance they would be in a stock application (as measured on the donor vehicle).|
|The distance between those two pivot points establishes where the brackets must be set to hold the pivots. And, to keep a nice, clean look, we want those brackets to mount directly to the side or top of the frame rail, and not extend to the outside or the inside of the frame by any noticeable distance.
We'll be looking at the chassis fabrication in much greater detail later, but Photo 1-14 might help explain how the axle pivot points and mounting brackets (see arrows) determine the width of the frame, which for this set of axles turns out to be 32" from outside-to-outside of the frame rails. Since we will be using a simple ladder-type frame for this project, the frame width will remain the same 32 inches from the front to the rear of the frame.If the above is confusing at the moment, don't be too alarmed. Hopefully it will become more clear in the next chapter, where you will see the full-size frame and mounting brackets being fabricated, and you can see more clearly how the I-beam geometry dictates the frame width.
Selecting a donor
Even though we are creating our own hand-fabricated frame and body, there are still a ton of parts and pieces that are necessary to complete any scratch-built hot rod. Most of those parts and pieces will come from a donor. If you want to keep your costs to a minimum and be certain the parts work together and are suited to the design, donor selection is critical. I own three scratch-built rods, and all three have used late 1970's Ford F-series pickup trucks as their donors. The reason is simple: bang for the buck...or if you'll excuse the pun, bang for the truck.
From one $300 donor you can salvage:
- A decent V8 engine ranging from 302 to 460 cubic inches.
- A hearty transmission, either C-6 automatic or standard 3-speed.
- A very stout rear end, either a Ford 9" or a Dana 44.
- An independent front suspension with the "look" of a traditional hot rod straight axle.
- Disc brakes for the front and decent-sized drums for the rear.
- Steering column.
- Usable leaf springs.
- An assortment of additional minor parts and pieces.
Every rodder will have their own ideas about what make, year and model they might want for a donor. For my particular purposes, nothing can come close to the 1978-1981 F-100 or F-150 in terms of cost and usefulness. Personally, I'm not choosy when it comes to Ford, Chevy or Mopar under the hood. They are all quite adequate engines for a hot rod intended purely for cruising and having fun. If you are a hardcore racer or have major horsepower demands, it becomes a different story. But for my needs and wants, I'm looking for the donor with the most usable parts possible with the lowest price tag. So, the F-series fits me perfectly.
For the sedan delivery project, a local 1979 F-100 was found in non-running condition for $150 (Photo 1-15). The non-running engine was not a factor since a complete overhaul would be done anyhow. It was also a 3-speed, which would make for an even more interesting project.
After getting the truck home, it was stripped down to the chassis as shown in Photos 1-16 and 1-17, and all the usable parts and pieces were salvaged, marked and boxed up . The rusted frame and body panels were tossed aside and donated to a local scrap collector who kindly visits once or twice or year to clean up the yard.
Tools of the trade
Any job requires appropriate tools. Most hot rodders will already have assembled many of the basics, but for those who may not yet have a fully-equipped garage, this list is being provided to help prioritize your future tool purchases. These are the tools which, for the most part, are essential for the two main elements of the scratch-built car: frame construction and body fabrication. There are also a couple of suggestions at the end of the list regarding paint and upholstery tools. Some builders may choose to farm out those particular tasks, but the tools have been included here for those who want to take on paint and upholstery work as well.
As noted earlier, I am a firm believer that 1920's and 1930's-era bodies can be fabricated without the need for expensive or exotic equipment. The Italian tradition of coachbuilding, through the early 1950's, fabricated car bodies using the most basic of tools including wooden stumps, sand bags and an assortment of hammers and mallets. In the 1950's book Sports Car Album, John Freeman and Alexandre Georges include stunning pictures of body panels for Italian cars being hammered with mallets over old tree stumps. And there are a number of websites, including one of the best, Metalmeet.com, where these basic and inexpensive metalforming techniques are explained and discussed in great detail.
The black roadster pictured in the introduction section was built from scratch without an English wheel, planishing hammer, metal brake, power hammer, shrinker/stretcher, bench press, bead roller, metal sheer, or mechanical metal rollers of any kind. For the sedan delivery shown in the later chapters of this book, an entry-level Harbor Freight English wheel (approximately $300) and planishing hammer (approximately $130) were purchased and used on the project. However, the car could have easily been completed without these two tools. The tools make the work go a little faster, but the actual results achieved with these tools can also be accomplished with basic hand tools and some hard work.
Obviously, if you are going into business to create these bodies you would need to keep your labor costs to a minimum, which justifies an investment in high-end machinery. But for the hobbyist, very satisfactory results can be achieved without any special high-dollar equipment. Yes, it demands a lot of time. But time is the one element most rodders have available to invest. And when it comes to creating scratch-built bodies, time can pay off in spades.
That's not to say you don't need tools. You do. But these are tools most hot rodders either already own or ought to own if they are serious and have long-term love for building cars. These are also tools some folks can access through buddies, a local car club, friendly shops or a local trade school. And even if these tools need to be bought, they can almost all be purchased for about the same cost as one high-end English wheel.
Here are the principal tools used during construction of the sedan delivery.
|1. 14" Metal chop saw - essential. I use a DeWalt, but many good ones are available for around $150 or less (Photo 1-18).
|3. Welder - essential. Alternatively, live next door to someone who has a welder and knows how to use it. I prefer a MIG welder for all-around use and I happen to own the Miller 175 wire feed (Photo 1-20). However, Hobart and Lincoln also make very good MIGs. A decent welder with required accessories is going to be one of your two most expensive pieces of equipment, running between $700 and $1,000 for a machine that is up to the task. I also have a stick welder (Photo 1-21) which comes in handy for some specialty items, but I do not consider it essential at all, just handy.|
|4. Drill press - essential. The heavier-duty, the better. I have a Craftsman circa 1978 which I've abused since it was new without a single problem (Photo 1-22). If you don't already own a good drill press, this is something you might be able to find secondhand and save some bucks. The bigger industrial machines hold up pretty well over time and can be a good investment providing they still run true, and there is no damage to the bearings or other working parts. If buying new, don't waste your money on the really cheap units from big box stores. Most of these are good for wood at best and will not provide satisfactory performance for the thick metals you will be drilling. I believe Craftsman is a good bet for the home shop, and with a 1 hp motor, these units, or other comparable brands, can be found for $600-$800.|
|5. Compressor - essential. Not only to paint, but to run air tools like die grinders, sanders and media blasters. If possible, opt for a two-stage unit with a minimum of 6-10 hp and an 80 gallon upright tank. Check the cfm output and psi ratings to compare quality from unit to unit. Horsepower and tank size don't tell you that much; it's the cfm and psi ratings that tell you if the machine will do the job. Here's the tag from my compressor (Photo 1-23) and a shot of the compressor itself (Photo 1-24). Your compressor is the other major expense on this list rivaling the cost of a welder. Figure on spending $800 - $1,000 for a unit that will keep up with any air tool in your shop.
6. Bench vice - essential. Get a good one and a big one. You'll use it almost every day. Cost will be $75 and up depending on the quality and size (Photo 1-25).
|7. Clamps - essential. Zillions of them. Of all sizes and all shapes. You can be almost certain that no matter how many of them you buy, you'll use them all (Photo 1-26).
8. Assortment of metalworking mallets, hammers and dollies - essential. You can pick up adequate body and fender sets (Photo 1-27) for under $50 from Harbor Freight or Eastwood, and they will have most of what you need.
|9. For shaping sheet metal, I mostly use a plastic-headed teardrop mallet like this one from Eastwood (Photo 1-28). In addition, if the metal is really stubborn, you'll need to have a couple of small sledge-type hammers in your arsenal (Photo 1-29).|
|10. Blasting cabinet and/or portable blaster - almost essential. I recycle and make use of a lot of used parts, and that means a lot of rust. Media blasting is usually the fastest and best way to clean things up. I have an inexpensive Harbor Freight cabinet (Photo 1-30) and a portable blaster for doing larger parts like rear ends and axles (Photo 1-31). As an alternative to purchasing, check out your local area for an outfit that does media blasting. Their price may be cheaper than buying the equipment if you only intend to build one car. If buying new, a freestanding cabinet will run $225 and up, while a portable blaster will be between $100-$150 for something adequate for the home shop. You could, in a pinch, do all your parts with a portable blaster. But be warned, it is very messy and it is difficult to recycle whatever blasting media you are using.|
|11. Bench grinder - almost essential. The alternative is using your 4 1/2" angle-head grinder. But, you'll find a bench grinder much easier and safer for many grinding chores (Photo 1-32). An adequate grinder will run from $50 to $75 and another $30 for the stand if you need it.
12. Assortment of air tools - almost essential. I use a right-angle and a straight die grinder, jitterbug sander, orbital sander, rotary sander, sheet metal sheers, reciprocating hacksaw and a right-angle air drill (photo 1-33). I would highly recommend all of these, but you could get by without them in a pinch.
|13. Long shaft grinder - almost essential. I use a Chicago Electric from Harbor Freight (Photo 1-34) and it has held up well. These run $30 to $50.
14. HVLP paint gun - Highly recommended if you intend to do your own paint and primer work. You could possibly borrow a gun if you are short for funds, but it is best to learn and practice with your own gun. Harbor Freight sells lower-end guns that are adequate for primer, and some rodders have even had good luck shooting color with them as well. My own choice for a decent and economical setup is the Devilbiss Finish Line 3 kit (around $230) which includes the gun, air regulator and four different fluid tips so that you can shoot everything, from epoxy to clear coat, with just one gun (Photo 1-35).
|15. Full paint suit with remote air supply - nearly a must. Yes, a lot of folks paint with only a minimal face mask, but if you value your health, you owe it to yourself to look seriously at remote air masks and hoods. There are a couple of decent units for home and hobby use. I happen to have the Hobbyair shown in Photo 1-36. They will set you back about $400, but they can save you a lifetime of hospital and doctor bills.
16. Sewing machine - highly recommended if you intend to do your own interior and upholstery. What you need is a machine with a walking foot and a high-lift foot (so that the foot can be raised high enough to get multiple layers of fabric and foam under the foot). One way to keep your cost down here is to look for a used upholstery-grade machine. Unfortunately, if you don't know much about the machines or you don't know someone who can look over the machine for you, this could end up to be an expensive alternative if there is excessive wear on the machine. Another option is to borrow or share a new machine with others who might be friends or in a local car club. I recently loaned out my machine to a local rodder who was doing new upholstery for her '48 Chevy. It worked out well for her, and I figure the machine might as well be getting some use while it's sitting between my own projects. I bought the Tacsew T111-155 for my upholstery work, but there are any number of good units on the market. I've seen the Tacsew on eBay recently for around $600 for the base unit. You should strongly consider investing another $300 to get the table, stand, and most importantly, the servo motor rather than the clutch motor. The servo motor allows precise control of stitching speed, particularly when you first engage the motor. This feature offers great benefit to newbies or folks with limited sewing experience (Photo 1-37).
One final note regarding sewing machines. Yes, it is possible to sew upholstery fabric with a typical household machine (Brother, Singer, etc.). If you were only sewing fabric, this would be a very viable option. However, nearly all automotive interior work requires that you sew through backing foam, sometimes up to 1/2" thick, and sometimes those thicknesses are layered one over the other. The problem isn't the needle going through the material, it's getting all that material under the foot, and then the machine having the capability of moving that big wad of material under the needle without having it slip or bind up.
While an upholstery-grade machine is nearly a must if you want to tackle this portion of your build, there is a money-saving option. If you only intend to do one car, there is a pretty lively market on eBay and other places for used machines, especially machines with very few hours on them. So, you can often get a fair return on your investment if you sell it after you are finished with your project.
In addition to the tools mentioned above, this book assumes the reader owns or has access to the more common tools associated with any automotive work such as sockets, wrenches, screwdrivers, hammers, crowbars, drills, saws and the like. Unfortunately, no list of tools can ever be totally exhaustive since as soon as the list is completed, someone would come up with one more tool that would be handy to add to the list.
What I really want to make clear by itemizing the above list of tools in such detail is the absence of any of the exotic or expensive machines we often associate with the craft of coachbuilding. Instead, our tool bag is primarily filled with common ordinary items that can be found in nearly every rodder's shop or garage. Granted, any high-grade metalworking tool you can afford will, in fact, make your work easier and go a bit quicker. But there is no need to postpone construction of a scratch-built body because you can't afford a nice English wheel or a fancy bead roller. Those big ticket items are simply not necessary to get that dream of yours completed and on the road.
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