Build a Bearer of Burdens

by Wade Tarzia in Workshop > Cars

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Build a Bearer of Burdens

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack on car, side, , August 2007.jpg
And so there came a day when I traded my old Rodeo for a Ford Focus, and though I gained reliability and fuel efficiency, I lost much cargo-carrying ability for bring kayak and outrigger canoes to the water. Exeunt the evil (though not the most evil) SUV and its practical applications for True Sports Utility.

But surely the Ford Accessories department has an answer. 'Hello, yeah, parts department. How can I help you?' 'Do you have a rack for a Focus?' 'Yup, for the wagon model.' 'Not the ZX3 coup?' 'Nope.' Short and sweet, the answer is No in the comfortingly predictable American Automobile Tradition.

Enter now The Grand Thule. Shrouded in swirling northern mists, enhanced by the evocative name of the ancient kingdom whispered about by the Greek traders and Roman invaders of Iron Age Europe, The Grand Thule called its ravens named Adventure and Spirit (in translation), and they croaked, 'Do we have the thing for you! You pay only $400 AND you get the aura of our name besides a 200 pound capacity!' I bowed and replied, 'I have a short roof Ford Focus.' The ravens screamed and flew off, The Grand Thule withdrew into a blast of icy wind peppered with ice shards, and I heard the fading but still grand voice, 'We offer no rack for your model at this time.'

Enter next the fresh, sleek, happy salesperson at Eastern Mountain Sports. 'We have just the thing for you, this Yakima roof rack. Oh, you have a short roof and the rain gutters do not extend past the door (coup model)? No problem, for we have this wondrous accessory.' She rang a bronze cymbal, and cloaked devotees came in from the carven stone grotto that all EMS stores have out back (and you thought it was all steel racks and stacked cardboard boxes, didn't you?), singing a hymn to the Updated Demeter, goddess of the earthy-crunchy sportslife. They bore on their litter the Sacred Short-Roof Adaptor. There followed a poetic explication on its use, chanted in decasyllabic meter. 'And your sacrifice need only be in the amount of $300 (on sale!).' That left me with one solid roof connection at the front on the rain gutters, and a won-drous bracket with a rubber pad resting on the roof top for the rear support, connected by the lon-gitudinal rails. I suppose it would work, but the engineering configuration did not fill me with $300 worth of awe. Now what?

Enter the workshop. It smells slightly of paint and sawed wood. The floor is dotted with drops of cured epoxy. The tools wait in their raw wood racks, saying nothing directly (they seldom speak like that), but insinuating promising possibilities (always!). Towla, a blacksmith character in my novel The Sorcerer's Chain, once made the comment, 'The only certain thing is the hard handle of a tool.' These fictional characters sometimes seem realer to me than many a flesh and blood persona (how sad; that's on me). I took his advice.

UNCREATIVE SUMMARY

I built a hasty and crude roof-rack to fit my focus. I used scrap wood at hand (2x3 studs, 1x2 strapping), scrap rope at hand, Tightbond Glue (get the new Tightbond III waterproof type if you have to buy), some epoxy and graphite power left over from boat building (not needed but I wanted to try the graphite as a tough, slippery bearing surface for the kayak), some screws at hand, and then I bought one piece of 8 foot x 6 inch wide pine board for about 10 dollars, and two ratcheting nylon strap tie-downs for about 12 dollars.

I hastily painted it white to match my car, but would have used white in any case because that's the paint left over from boat building (exterior latex primer and glossy topcoat). I padded the roof-bearing surfaces with pieces cut from an old closed-cell-foam sleeping bag pad (end-lessly useful in projects, and you can sleep on it too).

The rack works great (have driven with my 70 pound kayak on top at highways speeds for about 400 miles so far; I can now also carry long heavy pieces of wood and uncut plywood -- the stuff I can't fit inside the car itself with seats folded down) and saved me a lot of money. How much would it cost if you had to build from all newly bought parts? Well, I don't know, but I'm think-ing not more than 40 dollars (probably less -- everyone has some glue, screws, and scrap wood available), still a deal.

The following steps show vaguely how; they are suggestive instructions since your own car's di-mensions and configuration will differ from mine.

How It Works

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, strapping on August 2007.jpg
C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, strap around hinges, August 2007.jpg
The cargo straps go through holes in the primary cross-bars (white pine 0.75 x 6 inch, as knot free as possible, and with grain running perpendicular to surface if possible (quarter sawn, which reduces effects of shrinking). I open the doors, run the front strap through the passenger compartment, connect, and tighten.

In my car and for my height, the straps lay just behind the plane of the headrest, and interfere with nothing. But be sure to leave the heavy ratchets on the cross-bars, not inside the cabin: you do not want them bouncing around inside the car, hitting you on the head, though if well thought out, that method might keep you awake on long drives. The wider the straps, less wear on your rubber door seals. I need to sew on pads to reduce wear there, I think.

WARNING: RAIN CAN SOAK THE STRAPS AND DRIP INSIDE THE CAR via interesting physical laws after a while (could be a good high school science class experimental demo). Do not leave the straps on over-night in the rain. You will get in the next day, and wonder why your butt is wet, at a time when wetness if not socially acceptable (meeting mate's parents for first time, shopping, eating out, etc.).

-- close-up photo of front cross bar with strap shown

For the rear attachment, I open the hatchback, run the straps under the hinges but leave straps loose for now so that when you close the hatch, the hinge will NOT scissor the straps (!). The hinges seem heavy enough to bear the load on the rack, which is low in the fore-and-aft direction.

Close the hatch, BUT insure the straps are loose and hanging under the scissoring action of the hinges, and tighten the straps. Again, protective webbing on the straps where the straps go around the hinges is a good idea (no, a Great idea -- much wear here). I have a scavenged piece of heavy and wide nylon tow strap found by the roadside, which I plan to sew over the strap wear-points.

--close-up of open hatch showing strap

Note -- The rack itself has 'soft' attachment points made of heavy nylon rope loops on which a second set of cargo straps hook to tie down your loads. These will not damage loads carelessly plunked down or dragged across them, as might happen if you used eye-bolts.

Designing Your Roof Rack (by Seeing How I Did Mine)

Well, the word 'design' here is a little compromising, but, no matter, I will eschew the self-deprecation (since adequate numbers of appraisers will selflessly fulfill this function for me soon) and move on.

(A) SUMMARY OF DESIGN PROCESS, WITH WISDOM ATTACHED FOR YOUR CONSIDERATION -- The design work is mostly all about (a) staring at your car a while, let the mind work without constraint or formality, (b) taking some measurements, (c) writing the measurements on the wall of your garage, then (d) going to a book store that sells coffee, (e) buy a book, (f) buy a cappuccino, (g) read, a little, think a little, and (h) sketch the roof rack now that you subconscious mind has been uploaded, fed, distracted from the fact that it was given a job to do, and finally, asked to emerge and perform.

Therefore: KNOW YOUR MIND! It can be a good ally if treated properly; this treatment may include exploiting it, fooling it, making it promises that will be hard to keep, and so forth; but sleep well, for the result will be the justification.

(B) THE PROGRESS-MAKING PHASE -- Plan basic measurements; (1) get measurements for roof rack width (SUGGESTION: you want the bearing surfaces of your rack to miss any rubber door seal/rain gutter seal by at least an inch, so that sliding rack will not push them out); (2) get measurements for the length of the rack, especially its bearing surface points (ADVICE: these points should not 'oil can' your roof, and should miss any antenna mounts; get the bearings close to the strong roof edges as long as your consider the suggestion above); (3) and get measurements for the points where your cargo straps will wrap around car parts and holes -- with some thought as to the points on the rack where the straps will attach. This last point is more interesting than it sounds. See Discussion B1 below.

B1 Discussion

The strap-to-car and strap-to-rack relationship may sound a little kinky but is consensual and critical. I suggest planning some 'tensional offset' (you are granted use of this excellent phrase under the Instructables Legal Agreement) into the car-to-rack attachment points.

Example: plan the front strap to go around the front door rear corner (doors are open when running cargo straps through! do NOT tie yourself in! how embarrassing) and the rear strap around rear door rear corner if you have a sedan. No sedan? Then straps go throughfront door rear corner and around the hinges of your hatchback/trunk-hinges, etc. Get those measurements, I say, and then plan the attachment points on the roof rack (simple holes for the straps); the attachment points on the rack should be INSIDE the attachment points on the car by at least a few inches (more below).

Why 'rear corner of doorway' and suchlike? The dynamic aero-pressure of driving will push your load rearward, so at least one set of straps should resist that by pulling on the rear corner of your doorway). In contrast, when you brake, the load will shift forward, so one strap (front or rear) should be placed so that it will pull on the load when it slides forward (I suggest the rear strap, to always provide a straightening moment force on your load when braking). With enough angle on both sets, the rack's fore-and-aft position on the roof can be well maintained. Remember too, you have paint on your roof, and you do not want the rack to slide, wearing the paint.

What about the lateral positioning? To resist cornering forces and wind shear? Do not take any corners, and drive at an angle to the wind to always keep the resolved vector (or 'apparent wind') straight over your roof load. If you cannot do these things, then know that the foam pads, screwed to the wooden rack, and the tightened straps seem to keep the load centered on your roof (I had about a half-inch shifting; using solid rubber rather than oft closed cell foam might stick to the roof better (saw it off the 'roof extension accessory' of a commercial rack! The DIY gods will protect you from the offended commercial gods).

Building the Rack, Part 1

C:\Documents and Settings\Wtarzia\Desktop\roof rack\roof rack, gluing on end supports.jpg
The pictures tell all, I think. There is no rocket science here or adanced CAD (or simple CAD!). But anyway...

A -- Start with the fore-and-aft pieces (rails). Cut to length, round off the edges. To keep rails level by the end of the project, depending on the curve of your roof, you may need to add 'raising pads' at the rear of each rail, OR do a graceful job scribing the curve of your roof on the rail-wood so the rails will fit the roof (rails will need to be wide/tall enough so that after the curve is cut out, enough wood remains for strength).

I added pads since I was working with the wood I had (2x3s, not wide enough to scribe a roof curve on the curvy Focus ZX3 and leave enough wood for strength). (That 'ZX3' sounds pretty cool, but it is code for 'the most basic model you can buy'; good marketing strategy, though.)

B -- Or start with the cross-bars. (1) Cut to width, round off the edges. Elliptical edges will be more streamlined. Cross-bars should be wide enough for intended loads (for me, they were a little over 48 inches wide so that I can lash 4x8 foot plywood sheets on the rack), but should NOT be con-stant head-bashers of you or pedestrians.

(2) Round off their ends with wide radius (jig saw) for when you do hit your head on them.

(3) Chamfer/radius the edges to a small radius of 0.25 inch or so (keeps paint better, less prone to dent, and is smoother = safer).

(4) I added end cross-pieces (quarter-round oak scrap I had) on the cross-bar ends to brace the pine boards across their end-grain to resist splitting and also to reinforce in case later I drill holes there for attachment points on the extreme ends of the cross-bars.

The photo shows the end pieces being glued on but more importantly, the holes to pass the straps. I made them too big for a reason too embarrassing to discuss. Just forget about it. What was I thinking? But.... the holes are spaced according to the width of the door opening (across the roof) for the front cross-bar and the narrower spacing of the hatchback hinges for the rear cross-bar attachment points.

-- photo of cross bar end pieces clamped

Building the Rack, Part 2

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C -- I felt a need for strengthening the cross-bars with a beam (the 0.75 inch thick pine boards would flex, perhaps vibrate at the natural frequency of the car and destroy it, and anyway, maybe just break), so I glued two layers of strapping (you can use one piece of 2x2 if you have it) on their fronts (leading edges), and rounded them off as a nod to aero-smoothing but just a nod, they are still pretty blunt. With ambition and time, you could make strengthening braces on the pine boards nicely elliptical, or airfoil-ish, or epoxy on Dow insulating foam leading edges (surfaced with fiberglass cloth) shaped like wing leading edges, to lift your car and reduce its road friction. That was a joke. The beams also let you keep the metal strap ratchets on the board, i.e., under your load, since the load rides on the braces, so that your load does not rub against the ratchets and become scratched!

-- photo of beam/rail being clamped and glued

D -- I epoxy-graphited the top of the braces (load surface) to let kayak slip off for load-ing/unloading. I will tell you someday if that was a good idea. Strips of high-density plastic might be just as good or better (sold at woodworking stores as saw-stand lumber slides). Then I painted over the graphite as an experiment about how well paint will stick to it, and as an indicator of where most of the wear will take place, to be used if/when I improve this design with other features.

Building the Rack, Part 3

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, loading canoe August 2007.jpg
C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, screwing on foam pads.jpg
E -- Loosely lay out the cross-bars on the rails, spring clamp, think about it, and draw pencil marks where you think (1) they all attach, and (2) where any load-attachment holes will be drilled. You will need holes for the straps holding rack to roof, and holes for rope loops, eye-bolts, eye-straps, etc., for strapping loads to rack.

Note -- I like rope loops (3/8 inch, and tie them with nonslip knots, especially the bowline bend or some other) because they are cheap, strong, flexible (will not damage load if you rub against them), and easily checked and replaceable. You can paint the nylon rope loops if you think UV damage will degrade them sooner than wear and tear.

F -- Now assemble on your roof loosely and think about it. Make final adjustment and change your marks if needed. Simulate the way you will load your loads (such as kayak) so that the rack will intercept all bashing, damaging, angered motions of the loading event. If you want to spend more money, now is the time to buy or build rubber rollers to help load the kayak on the rear cross-bar, or install plastic slidey things.

G -- Now level the assembly on the roof if you did not scribe the roof curve on the rails. I used wood wedges to level the rack on the roof by lifting the rear end of the rack, took the measure-ments, and built spacer blocks (angled to the roof angle) by laying the blocks against the wedged up wrack and drawing the outline of the relationships on the blocks. Finally, I shaped the blocks, glued them one the rails, and reinforced them too with a 3/8 wooden dowel glued into block and rail. The photo shows the spacer blocks leveling the rack as well as the illustration for the Step J, 'test load your kayak.' Just trying to save Instructables' data space.

--photo of kayak leaned on the rear cross-bar

H -- Then glue and screw the whole assembly. Sand and paint.

I -- The final step is to cut your foam pads to wrap around the front rail and the rear leveling blocks. I used stainless steel screws and washers to attach the pads (the washers prevent tear out).

--photo of the foam pads being screwed on



Building the Rack, Part 4

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, still room to open hatch, August 2007.jpg
J -- Practice loading the typical load or kayak. Tension the rack straps enough to hold it all down but DO NOT destroy the rubber seals around the edges of your door frame! Let me know if you have a way to avoid that! Because I have no clue except for using widest straps possible, foam pads, etc.

I load a 70 pound kayak by myself, which is sometimes a graceless event. The important thing is that while resting kayak on the rear cross-bar, it does not touch your car. If you measured well, it should not.

Afterthought -- I think I could use a short upright brace on the end of the cross-bars (one side would suffice) so the kayak will not slide off the side of the car on a bad day (could be graphite coated, plastic-strapped, or have a roller to ease pushing the kayak across).

In the photo, you see there is still room to open the hatch with the load on; see now why you should level the load by raising the rear of the rack?

WARNING: If you close the hatch without loosening the straps and pulling them away from the hinges, the hinges could scissor your straps if you thoughtless close the hatch on them.

--photo of kayak loaded and hatch open

Admire the Load

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, kayak loaded, August 2007.jpg
K -- Admire the completed system! I think it looks like a Genuine Ford Accessory from distances greater than 15 feet. In fact, many are the times I have passed Ford Parts trucks on the highway and saw the drivers scratching their heads and making sudden cell phone calls.

-- photo of loaded kayak on car in yard

Enjoy Life, Courtesy of Your Roof Rack

C:\Documents and Settings\Wtarzia\Desktop\roof rack\Roof rack, reward 2, August 2007.jpg
Don't forget to enjoy life, ever. It is so easy to forget, strange as it may sound. We can resemble an ant colony, each of our members assigned a task with other tasks waiting in line. Blame the Puritans (America's very own religious fundamentalists -- the first ones but not the last, so 'some people' should stop pointing the finger at other cultures all the time) and their Work Ethic. Nations without a Puritan history probably have more pleasant philosophies about work.

In any event, here we are. If only the roof rack could bear other burdens, but no, it is a physical solution for physical problems. Expand holistically, and make the world itself bear the loads, as now....

Step L -- L for last step, but better, L for Lovely day on the water, the proof that it was all worth it.

-- photo of kayak on Bantam Lake swamp river