FRAME BUILD-UP PART I

 Prepping the Frame Rails

  Finally we Begin Construction on the Frame.!.!.! 

     We purchased new reproduction Frame Rails from Horton's Hot Rod Shop back in September of 2006.  They were made by American Stamping Company, which has been producing Frame Rails for many years.  The Rails are made by a very large press that forms the Rails in two hits of it's mighty press, the first hit cuts the metal to size and the second hit forms it to the unique shape of the 33-34 Ford Frame Rails.  What started out as simply as a sheet of 10 Gage metal, is now formed into the useful series of sharp bends and gently rolling twist that we will use as the bases for our Project COBRA'33 street rod.

     Before we ever mounted the Frame Rails, there was plenty of work that needed to be done for a project such as this.  We needed to fashion several adjustable Frame holders and positioners.  These we had out of 2" and 1-1/2" square tubing.  The ideal being to make several adjustable stands that would be placed under the frame rails and bolted to the top of the welding table, allowing us to not only support the Frame, but level it and hold it in the position we choose.  The frame has to be held in position, you need to insure that the two Frame Rails are square with each other and held level and at the height you need.  For this reason, the holders need to be made adjustable and strong.  We drilled our welding table down each side so the adjustable Frame positions could be bolted into position anywhere the length of the table at 3 inch increments.  This allowed us a almost infinite amount of adjust-ability, which proved very useful as the project continued along.

Boxing the Frame Rails

Pictures shows bare Frame Rails and Boxing Plates laying along side.  Care should be taken to remove just enough material to allow the plates to fit inside the rails.

     We purchased our Frame Boxing Plates when we bought the Frame from Horton's, though you can easily make your own from a sheet of 1/8" steel.  The first thing you need to do is fit the pre-cut Boxing Plates to the frame, adjust them back and forth till you achieve the best fit.  You will have a front and rear Boxing Plate for each Frame side.  I like to mark each Boxing plate and Frame Side with a simple "A" or "B" so as to not fix them up.  Also, once you have figured out the best fit of each plate, mark the Frame were each Boxing Plate starts and ends, this way you will be able to easily reposition each plate.  The Boxing Plates will need to be trimmed, they should be trimmed so they fit inside the Frame Rails with relative ease.  This will take some time, and at least the help of a side grinder.  Our Boxing Plates needed extensive trimming, with one needing the removal of 3/8" of material from the full length of a side, this we cut with a metal circular saw in little time, but would have taken hours with only a side grinder.  So, be prepared to allow several hours for the fit of these Boxing Plate, you may want to break it down to the fit of each plate.  This would allow you to feel like you accomplished something, and also allow you to take a break from the grinding.  Speaking of which, grinding is something you should not take for granted.  Eye protection is a must, you are using an abrasive disk to remove metal, which results in a sparky mixture of fine metal and disk pieces flying through the air, you and everyone around you need to be wearing protective eye wear and protective clothing.  Safety is your responsibility, and is really just a good habit to get into.  Once you decide to take safety seriously, it seems natural and completely ordinary to wear good safety glasses and protective clothing.  Building things is suppose to be fun, or at least it is for me, and I don't think it would be to fun if something were to fly into your eye and cause serious damage.  Your building a Street Rod to drive and have fun in, not to be reminded of a serious injury you sustained while in the building process. If you don't want to were the glasses and protective clothing for yourself, do it for you wife and children, they are the ones that will be effected and devastated when you can no longer see or work because of an injury you might have been able to avoid.  Safety is something you do for both yourself and for the ones you love, an injury hurts everyone.

     Hopefully now you have the Boxing plates fitting pretty good, the next step is to prepare the Frame Rails.  There are many items that get bolted to the Frame Rails, the running boards, fenders, and gas tank is but a few.  You will need to prepare for these and all the other parts and pieces that will be bolted to your Frame.  Boxing the Frame Rails is necessary for added strength, closing in that open side really adds to the rigidity of the frame, but it also eliminates the ability to get at the inside of the Frame Rail.  You will need to prepare for this loss of access by one of the following.

1.  Weld oversize nuts or "Weld-a-nuts" to the inside of the Frame Rails where other parts will attach.  I like to use oversize nuts, which can be bought in many hardware stores.  They are simply nuts that have a larger then usual exterior size for the type thread they are.  A typical example would be a 3/8" thread would normally have a 9/16" exterior size, but an over size nut might have a 5/8" exterior size.  Another great source for oversize nuts is to use "Unistrut" or "Be-Line" brand spring nuts.  I just simply cut off the spring part and the metal body is very large giving you great strength and plenty of area to weld to.  You will see them on the frame we are building.

     "Weld-a-nuts" are sold at many Hot Rod shops, and are small thin strips of metal (1/2" x 1" X 1/8" thick) that are threaded in the middle and are welded to the frame anywhere you might need a threaded fastener in the future.  They also work well, but are a little thin for some items I think. 

2.  If you do not want to use a nut or "weld-a-nut" then you can weld a piece of flat metal 1/4" thick at any of the spots that need a fastener, and latter drill and thread the piece for what ever thread size you might need.  This might prove beneficial later, as you can drill the hole exactly where it's needed.  Sometimes fitting up old or even reproduced body panels don't always fit just as they should, this might allow you the room needed for that misalignment.

      The large Rectangular threaded pieces are Unistrut spring nuts, modified by removing the spring portion.  They offer a thick, and secure mounting point for future use.

     Which ever method you choose is up to you, the main point is to make sure you allow for future attachments now before the Frame Rail is welded shut.  Another consideration is the amount of set-back for the Boxing Plates.  We kept our Boxing Plates set-back into the Frame Rails just enough to make the plate level with the rest of the Frame Rail when finished.  This produces a nice clean surface on the inside of the Frame Rail to run future items like brake lines, fuel lines and to mount items like fuel filters and brake proportion valves.  There are variables, like the "So-Cal" Frame which positions the Boxing Plate down into the Frame Rail by about 1/2" or so.  This type of mounting creates a lip at the top and bottom of the inside Frame Rail, which some consider better then flush.  The advantages they see by this type of mounting are the lip helps protect the lines (brake and fuel) mounted to the boxing plate and the lip provides for a better weld joint by providing extra surface to weld to, and not grinding the weld like one would if it was flush.

Here is a shot of the Blueprint we used to lay out our frame.

     The decision is yours to make, we choose to mount our Boxing Plates flush to the Frame, I liked the clean look, and simplicity of mounting anything we wish to a smooth and flush surface.  Again, the choice is up to the individual and the look they are after, both ways work.  No matter which style you choose, you will need to install small blocks to set the Boxing Plates on that will make sure they are set to the depth you want.  You can see in the picture that we used small sections of round tubing for our Boxing Plates to rest upon.  We simply measured the depth needed to keep the Boxing Plates flush with the top of the Frame Rails, and cut them to size.  I welded them to the Frame Rails in various places along the entire length of the Frame Rail, this assured me that the Boxing Plates would be well supported and flush the entire length of the Frame Rail.  There are many different ways to do this, and none of them wrong as long as the result is the same, the main point is to not only support the Boxing plate along the edges but also in the middle so it comes out flush and smooth.

     We also choose to run a length of conduit down the inside of our Frame Rails before we welded them shut.  This provides us with a easy and very hidden passage for future wiring, I think it was worth the added expense and effort, but you will need to determine that for yourself.  If you do decide to follow suite, and run the conduit in your Frame Rails, be sure to route the pipe so it doesn't cross any areas you might later need to modify.  Case in point, we well need to section a piece out of the rear area of our frame for the "C-ee", that area directly above the rear axle tube.  We must remove this section to make room for the axle tube, necessary because of the lowered stance we seek.  Other considerations might be the future addition of the braking systems pass thru fitting, that goes thru the frame in both the front and rear areas.  Like any other part you may choose to add, just make sure it's completely compatible with the current and future frame.

Picture shows the spacers we cut from a length of tubing to set the Boxing Plates to the proper depth.  Also shown is the conduit we ran the length of the rails for future wiring.

 WELDING THE FRAME

    The Boxing Plates have been fitted to the Frame Rails, all the threaded fasteners are in position, and you have decided what the finished rails will look like with regard to Boxing Plate setting.  Now comes the Welding.  First thing we must do is to lay the frame off in no more then eight inch sections, I like to play it safe and will lay my frame off in three inch sections.  What we are trying to do here is prevent to much heat from building up in one place or area.  The frame is not simply a flat long piece that can be easily held in a position and welded, instead it rolls and twist along it entire length with not much more then a foot or two of like area.  If the frame was flat, we could easily clamp it to our welding table and prevent it from distorting, plus any such distortion would be very apparent.  But since that isn't the case, be must use great care when welding the frame to prevent or at least hold to a minimum any changes in it's dimensions.  I have read where some claim that loading the frame from front to rear will also help avoid any such distortion.  That meaning apply tension with weight or jacks to the front and rear sections of the frame, pulling from front and rear.  While this may or may not be a good way to minimize frame distortion, we chose not to use that method, instead reducing the weld length and constantly jumping around from front to back, side to side and top to bottom with or welding to prevent any concentrated area of heat build-up.  Here patience is key, along with a good command of welding fundamentals.  For our Frame Boxing project we will use the MIG (Metallic Inert Gas) welding process.  This process involves an electric welding machine that supplies a constant quantity of metallic filler material protected from the atmosphere by a Inert gas most commonly Argon or a Argon mixture.  This welding process is very common in the automotive world used by both automobile manufacturers in the assembly of cars and trucks on the assembly line, and aftermarket companies and race teams building everything from NASCAR type race cars and to automotive exhaust systems. 

The Frame is ready to be welded.  The Boxing Plates have been fit and tack welded into the Frame Rails.  We laid off the Frame in 3" sections all along its perimeter, this will aid us when welding so we don't weld to long in any one section.

     Can I weld my own Frame? 

     Welding is a very particular skill that takes time to develop and master.  Time to practice welding on the many different types and thicknesses of metal.  Time to practice welding on the many different welding positions and environments.  Like any other obtained skill, welding is something some people catch onto faster then others.  It requires a steady hand and great eye to hand coordination, a general understanding of metals, and the ability to properly set-up the machine and prepare the materials to be welded.  Currently there are many books available that cover welding, from the beginners guide to the advanced welder, you are bound to fine several books that fit your interest and skill level.  Locally, Borders Books is a great source for welding instructional books, but you can also find an abundant supply on the web, just Goggle "Welding".

     Welding your own Frame is no place to start or practice your welding skills.  An automotive frame such as the 1933 Ford Frame we are building is subject to a great many stresses and torsional loads, these loads are, under some conditions, extreme and may even be life threatening!  Practice on similar gage metal until you feel confident in your ability to make consistent and quality welds, then if you feel you are up to it, try welding your Frame Rails.

Close-up of welded Frame section.  Next to come is the clean-up.  The Frame will be grind smooth for a clean look.  Because we are grinding the frame smooth, great care was taken to insure good weld penetration.  Grinding a bevel on the Boxing plate will help penetration.

CLEAN UP

     There is no way to get around clean up when it comes to welding, it's as much a part of the welding process as anything else.  For me, it's one of the more enjoyable.  I like seeing it all come together, looking good and taking shape. 

     You will need a few common electrical tools to make the clean up process go quickly and look great.  First on the list would be a quality 4-1/2" side grinder, this is the trade mark tool of the fabricator or welder.  The side grinder is small enough to get in 95% of all the places you will need to get into, and light enough that it won't wear you down.  You will need a few 4-1/2" grinding wheels, these are used to quickly remove material and shape the metal, they last a long time so don't over do it when shopping.  One word of caution when using these abrasive grinding wheels, the grinder operates at an extremely high RPM, most around or above 8,000 RPM!  Make sure you always visually check the condition of the grinding wheel before each use.  Just look it over checking for damage to the edge of the wheel or cracks running from arbor to edge.  It is not that unusual to drop or accidentally knock the grinder over, causing it to hit hard on the grinding wheel and damaging it.  Because of it's high RP Ms, any fractures or broken edges can greatly effect the balance and or integrity of the wheel resulting in a potential wheel failure at high RPM, which could be very dangerous to both you and others around you.  Trust me, I have experienced wheel failure at full RPM, and it is a very scary and dangerous situation.  Buy quality grinding wheels and attachments, it's just not worth getting hurt or injuring someone else to save a few bucks. 

     Next you will need an assortment of sanding disk, I like to use the 5" size.  These work great at cutting away metal and smoothing things out.  You simply buy a backing disk that attachés to the side grinder, in place of the grinding wheel and the sanding disk attachés to the backing disk.  Replacement of the used disk is super simple, just loosen a center screw and remove and replace the disk with a new one.  The whole process takes less then a minuet and you need no tools.  The disk are superior to the grinding wheels in that they contour to the metal to be finished, making them an excellent choice for finish work as well as general sanding.  The sanding disk come in a wide variety of grits, from the super aggressive #25 to the fine Finnish of the #200 grit.  I use a #36 grit 90 % of the time, it cuts fast and makes short work of most grinding situation.  Then when it's time for final sanding, I like to go to a #80 or #120 grit.  You'll find that no matter the grit, a soft touch can do wonders. 

     The key to finishing the metal is to only remove the necessary metal and no more.  The fact is, by grinding down the weld until it's flush with the Frame Rail, you are weakening the structure.  In reality, you really wouldn't want to remove all the weld, but because we are Hot Rodders and looks count as much as they do, we grind and sand the Frame Rails smooth.  This brings us back to the part about quality welds, you can now see why it's so important that the welds that box the Frame Rails be of the highest quality so the maximum amount of penetration happens.  If you have any questions or concerns about the quality of your welds, it may be advisable to have a welding professional box your Frame Rails.

ADDITIONAL BOXING

     One area we addressed that isn't covered by the standard Boxing Plates is the front Frame horn and rear Frame section.  The standard boxing plates end some distance from the actual end of the frame.  In fact many only box in the frame from the cowl to just in front of the engine, or only in the area of the front cross-member and or in the area of any rear cross-members.  This partial boxing is very popular, but in my opinion falls short of what boxing the frame should be all about.  Our Boxing Plates we bought at Horton's Hot Rod Shop were full length, and address the boxing needs of most any frame in it's entirely.  But as comprehensive as they are, they still stop far short of completely boxing in the entire frame.  For our project, we wanted a more complete boxing of the frame, but did not want to completely enclose the frame sections on the ends.  As you will see in the following pictures, we made our own end pieces and added some holes to allow us entry into the middle of the frame rails and access to the conduit we installed.

The front end of the boxed frame rail, and where it normally ends.  The holes in the Frame Rails are for the bumper brackets, since we plan on using a bumper on Project COBRA'33, we will weld in a few nuts for future use.

A look at the cardboard rendering we made of what the front frame boxing plate should look like, it's metal brother and the piece of sheet steel we cut it from

     For our rod we wanted the front frame horn to be fully boxed in, yet allow us access to the hidden conduit inside.  We made a cardboard template of the shape needed and traced that pattern on a piece of 1/8" sheet steel.  With the help of a plasma cutter it and the other side panel was carved out in little time leaving only a few minutes working the belt sander to bring it to a finished part.  You could use the side grinder to finish the part just as well, only it would have taken longer.  Once the new boxing plate was welded into position, we simply had to add a small metal plate to the end of the Frame Rail,  to finish off the frame section.  We welded out the boxing plate like we did all the others, working side to side and front to back, to keep the heat spread out and from concentrating to much in any one area.  Patience is the key, like with most welding jobs.  Use the sanding disk to finish off all areas and again only remove what is necessary.  We added the extra touch of a dimpling die to our access hole for a professional looking touch.  Dimple dies can be purchased at many fabrication supply shops, we purchased our set from Trick Tools.  They allow the fabricator to add a touch of class to a other wise ordinary hole.  Dimpling also increases the strength in the area of the hole, so it's a win, win situation.

Finished front Frame horn

A shot of the rear Frame section, and the boxing plate we made to continue the boxing all the way to the end of the Frame Rail.  Like the front, it is made of 1/8" sheet steel and has three different size holes that we dimpled.  This allows us future entry, while spicing up the rear section as well.

SETTING UP THE FRAME RAILS

     Now that the boxing is complete, we move on to the setting up of the Frame Rails for the rest of the assembly.  This is the point where we get to use all the fancy mounting and positioning tools we made earlier when we were preparing for this project.

     First off, we mount the appropriate size position-er front and back.  We are going to mount the frame as close to ride height as possible.  For those that do not know, ride height is the height at which the car, frame or any of it's parts will be when all is said and done and the car is sitting on level ground supporting it's own weight.  Why is this something we need to know and plan for?  If you do not know the Ride Height, you will not be able to set up the car to have the look and ride you want.  It is important to correctly set up the rear suspension.  There is but a few valuable inches of rear suspension travel available on most modern Hot Rods, so we need to make the most of them.  Combine that with the low mean look most are concerned with and that all important "Stance" and you see knowing and under standing the ride height is a very important piece of information to know.  Buy setting the car as close to the actual final ride height, we not only use this to mount and properly set up the rear suspension, but it proves to be just as useful when mounting other objects such as filters, transmission and even engines, in being able to see if there are in problems with regard to road clearance.  The closer you can assimilate actual running conditions, the better you are able to spot potential problems.  As a general rule of thumb, you don't want anything hanging down to be closer to the road then five (5) inches.  This means oil pans, transmission oil pans, fuel filters, and everything else that might be damaged form road Debra.

We positioned the frame on the adjustable Frame brackets.  Then we leveled and squared the frame.  Once it was in the correct position, we clamped it to the brackets.

 SQUARING THE FRAME RAILS

     Probably the most important step in working with the Frame Rails is Squaring them.  This sets the foundation for the rest of our project, and any problems not corrected here will show up later when it's to late to make simple corrections.  Everything we do now affects countless other aspects of our Hot Rod, from the body alignment to the way it tracks while running down the road.  Patients here is mandatory.

     The Frame Rails are setting on there mounts, and should now be level.  To hold the rails together install the rear spreader bar, it simply mounts between the Frame Rails with a couple 1/2" bolts.  For the front, we made a spreader bar out of 1" square tubing and welded two ears on it so it could be bolted in place where the front bumper brackets would normally go.  The width up front should be 30-13/16" between the outside of each Frame Rail.  

     The Frame can now be prepared for the middle cross-members or Center Frame section.  We are using a round tubing center section manufactured by Welder Series, which we purchased from Horton's.  The included instructions spell out the locations of the upper two cross-members, which we mark and hole saw out.  We are hole-sawing the frame because I feel it allows better penetration, which means a stronger Frame Rail then if we would have simply butted the tubing up against the inside of the Frame Rail.  By cutting a hole into the frame, the cross-member can be inserted into the Frame Rail on both ends which captures the cross-member and allows us to get a better weld all the way around the tubing.  Simply use a hole-saw that most closely matches the out-side diameter of the tubing, in our case the tubing measures 1-5/8", and we used a hole saw the size of 1-3/4".  When measuring the cross-member for fit, allow enough length so both sides of the cross-member fit back into the opening by at least an 1/8".  Install both cross-members and any members that tie the two cross-members together, remembering to only loosely fit them together for now.

     Squaring the Frame Rails to each other will require the aid of another person.  Pick a location at the rear of the frame, I like to use the mounting holes on the top of the frame as the reference, just remember to always use the same point when re-checking.  And find yourself a similar reference point on the front area of the frame, now measure the distance between the two opposite points.  Remember you and your helper need to be as consistent as possible when re-checking the frame after an adjustment, the key is to measure from the same point as accurately as you can.  The two measurement should be the same or at least no more then a 1/16" difference between them.  Loosen the clamps holding the frame solid to the positioning arms and adjust the Frame Rails back or forward until you have the same measurement from hole to hole.  Take your time and get this right, it's to late once everything is welded up and painted.  As you go Thur the process of moving the Frame Rails searching for that equal measurement, don't forget to also check that you are still running level side to side of the Frame.  Once the Frame Rails are set to the right measurement and level with each other, you can tack weld the cross-members to the sides of the frame rails and to the pieces that Tye the two cross-members together.  re-check all your measurement after welding, just to be sure nothing moved.

Frame Rails with round tubing center section install.  Picture shows the two Cross-members and the two pieces that Tye's the cross-members together.  Additional center brace shown in picture was needed to spread the frame to the correct dimension.

Another view, but from the opposite side.  You can see the center brace better that was installed to spread the Frame Rails apart to the correct distance.

     If everything is still square and level, you can go ahead and weld the cross-members to the Frame's inside rails, and the two cross-members to the two members that tie them together.  Since the frame is only lying down and the best welds come when you weld in position (flat), you may decide to only weld the top portion like we did, and later worry about the bottoms.  But do weld enough to  hold the frame in  position, till the frame can be flipped over and welded in it's entirety.

For more on the frame Build-up go to Part II