Step 1: Dump that Old Bumper!
First, locate all bolts affixing the bumper to the frame. Soak those suckers in PB/WD-40. Wait 10 minutes...and soak them again.
Unbolt everything, and drop the old bumper away. Take your time....those bolts are probably large, and you probably can't break them off, unless you're sporting 26" arms, and a 'born to kill' tatoo.
As for your old bumper, I'd suggest storing it, in case this project goes wrong, OR just in case you decide to sell the truck later, and fear your new custom dragon tooth bumper isn't going to be a 'good selling point. If you have plastic trim/moulding/etc surrounding your bumper, be careful removing those...you may need them later, and just jerking them off is sure to crack them...take your time.
Step 2: Measurements and Mock-ups
You need to:
- Have an idea of the type of design you are looking for
- Measure your existing frame mounting points
- Assess how you can mount your winch, and make appropriate measurements (if mounting a winch)
- Create several cardboard Mock-ups to give you a feel for what you want/can do
My design is a pretty simple layout, but nicer than just a random piece of pipe welded in place. Be conscious that the more complex your design, the more complicated the fit-up. Don't underestimate how long a more complicated design will take. It's easy to imagine an incredibly complex design...but it's considerably harder to produce it.
Measure Mount Points:
This step is key, and accuracy is critical. Assuming you can use the mounting points from the old bumper, you need to VERY ACCURATELY measure the distance between them, and all other relevant dimensions. Make a quick pencil sketch of the mount points and be sure you are intimately familiar with the layout.
This is the fun part (well, the most fun part). Get some cardboard boxes...and duct tape...and start cutting out panels, to mock up one side of your bumper. There is no need to mock up the entire thing (unless your design is not symmetrical). Create different panels, and experiment. Stand back from each one, and look at it from different angles. Take pix of each, so you can flip through them and compare different mock-ups you've created.
It's way easier to spend time now cutting cardboard and seeing what it looks like...than it is to do the same thing with plate steel.
Once you have a design you like, you will use the mock-up to create measurements for each piece of steel panel which will make up the bumper...remember...this is not a Swiss watch...so leave yourself some wiggle room in the measurements. You can always cut metal off...but putting it back can be a pain.
Step 3: Winches Optional!
I used a piece of heavy wall 2"x6" square tubing as my mount material.
You'll need to cut a notch in each frame horn to receive the 2"x6" tubing. Mark your cuts, check it twice...then cut away.
Test fit your tubing and winch to ensure your winch is free and open, and that it's not hitting anything (like the radiator mounts).
After you're satisfied with placement, weld the cross tube in position.
You'll have to drill your tube for the winch mounts, and be sure that those holes are dead on, as the winch MUST be fully and firmly affixed to the cross tube. Failing to do this winch assembly could literally kill someone. Imagine you shortcut this, or make a mistake...you sell the truck next year with a flimsy winch mount...and some 16 year old buys the truck. Out in the mud one day...he needs to winch out, and your mount fails in what our friends the engineers class as "catastrophic failure"....that's not something you want to happen...so if you aren't comfortable with this...get a seasoned welder/fab shop to do this setup.
Once this is all in place make the final welds, and get paint on quick. Preventing rust here is important.
Step 4: Main Panel - Creating an structure to work from
As is often said...getting started is sometimes the hardest part.
In our case the easiest way to get started is to get an initial structure you can build off of. In the case of this bumper build , this means welding the main cross plate to the two primary mounting plates which will connect to the frame. This will allow you to work from this platform/structure, to accurately assemble the rest of the bumper, and will allow you to 'test fits' as you create the rest of the bumper.
Reminder: I really suggest NOT welding on the bumper while it's attached to the vehicle. It's tempting...but don't do it. It's dangerous. I know it's done all the time (and you might see in these pix, I'm guilty)...but just take the time to remove the bumper after each test fit, and just weld it on the bench.
CREATING A STRUCTURE TO WORK FROM:
Using your cardboard mock-up, you should have come up with dimensions for your front main panel, and how deep the mounting panels will sit back on the frame.
1) Create your two panels (frame tabs) which will bolt to the frame. I used 1/4" thick plate, about 7"x10". Using measurements from earlier, drill mounting holes in those two frame tabs, so those can be bolted to the old bumper mount positions. With the truck sitting on level ground, make SURE you drill these so the frame tabs sit parallel to the ground (use a level to check). Test fit, and measure repeatedly, until these are perfectly the same distance out from the truck, and at the exact same distance from the ground on the left and right. If you get this uneven, the rest of your bumper will be a mess.
2) Bolt the two frame tabs to the frame. Tighten your bolts completely.
3) Use a stand to 'crib up' the front main panel, so it's in contact with the frame tabs you just bolted on. I cut my front main panel from 1/4" plate (same as frame tabs). Once in position, use a square to ensure true-ness, and tack the front panel to the frame tabs you bolted onto the frame. Ensure this is a strong tack weld, as you'll be building off of this structure, so it will be coming on/off the truck for test fits...and you don't want this to break mid-way through the process. You also don't want to have it welded so well, that you can't cut it loose if you figure out you have a problem during the build.
Step 5: Keep building! Adding corners
Reference your cardboard mockup corners, and check those dimensions. Pull your mock-up panel for your corner, and affix it to your 'real' bumper that's bolted up to the truck. Move the cardboard around, and fine tune it, until you figure out the dimensions and angle for your corner panels. I cut my corner panels out of thinner steel than my main panel (I used 3/16" on everything other than the main panel and frame tabs).
Once you have the cardboard right, transfer that as a stencil to your 3/16" plate, and cut your first corner. I used a bandsaw to cut my panels, as it's cleaner than a plasma or torch. You can use a jigsaw, sawzall, or anything you want, but remember, you'll have to clean up any rough cuts...so the cleaner the cut, the better.
Once cut, tack that panel in place. As long as it's tacked lightly, you can use a hammer to 'tune' the angle by tapping it in or out, until it's at the angle you want.
Now that you have the angle where you want it, use a protractor or similar to gauge and record the angle of the panel you've tacked in place. Then complete the same operation for the other side of the bumper, using the protractor to ensure both angles are IDENTICAL.
Step 6: Adding the Upper Panels
Once again, using your cardboard mock-up panels, determine the size and angle of your upper panel(s). In my case, I had a left and right panel, as I wanted to leave room to access the winch in the middle. If you didn't mount a winch, you can probably get away with one continuous upper panel all the way across your bumper.
After using the cardboard to determine the exact size of your upper panels, transfer that size (as a stencil if you can) to the 3/16" plate steel, and cut it out (again, using a bandsaw, sawzall, or similar). I'd suggest you only cut one panel, and position it first, before cutting the second. That way, if you run into an issue with size, you won't waste the other steel.
Once cut, tack the first upper panel in position. Check the angle. Remember that truck bodies move in relation to the frame...so don't make the tolerance between your upper panel and the truck body too tight. The truck body could move slightly under load and contact your steel upper plate, resulting in scratched paint, or worse. Make sure there's some wiggle room
Step 7: Completing Corners
Continue to use your cardboard mock-up panels, to determine size and angles. Create your two remaining upper corner panels. I chose to do my rear-most upper corner panel first, leaving a gap. This is again all out of 3/16" material.
On my corners, I simply stenciled the gap to create the final inside piece, rather than trying to get into complicated geometry. Feel free to do the later, but you'll spend more time on the geometry, than you will just filling in the gap using pencil and cardboard. If you have already fired up your favorite CAD program (Google Sketchup), then you're doing this wrong, you overcomplicated person you!
Step 8: Test Fit and Trimming
You'll need to bolt up your bumper and go back to your original sketches. After you have a peek at your sketch, and your mock up panels, use keel chalk to mark lines for cuts. Once you've marked the lines, use a sawzall/jigsaw/etc to make the cuts.
Once complete your bumper should be starting to look closer to the final overall form.
Notice in these close ups, no welds are complete yet...just in case I need to cut something loose.
Step 9: Cutting in Winch Port
With your bumper OFF the truck, cut use a ruler and keel chalk to find and mark the center of the bumper. If you've already mounted your winch in the frame, be sure to keep the port lined up with the front of the winch as related to the frame (vertically). Once marked, use whatever cutter your prefer (I used a plasma cutter) to pop the hole in, that is appropriate to your fairlead roller setup. My fairlead setup came with a sheet telling me the minimum hole size for the cable, as well as the bolt pattern for mounts.
You'll want to also drill your holes for mounting the fairlead roller Be SURE you cut the port wide enough that your winch cable will not contact the steel plate, or you will certainly destroy your winch cable at some point. I went a little larger than the paper recommended to avoid a frayed winch cable.
This hole will be hidden by your fairlead roller, you can get away with a slightly sloppy cut on this one.
Step 10: Cutting in Recessed Light Pods
I chose to create recessed 'light pods' for two driving lights. If you choose to do this, you'll need some pipe slightly larger in inner diameter (ID) than the outer diameter (OD) of your chosen driving lights.
First, cut yourself two lengths of pipe (I used a bandsaw here), which will allow you to recess your lights slightly, and will give you somewhere to mount them. I used about a 4" long piece of pipe on each size, with an ID that allowed my light room inside (including some wiggle room).
After cutting your pipe for the pod, chalk a line onto the front plate of your bumper, using the light pod light as a stencil (do the left and right pod).
Use your cutting tool of choice (again, I used a plasma here) to cut both holes using your marks. Be conscious that you will be welding in the light pod pipe, and that will come back a bit toward your truck. be sure it's not going to interfere with existing bodywork/etc.
After you cut the holes, slip your pipe joints in the hole as a test fit. The cleaner your hole you cut, the less you will have to make up with welds to cover you mistakes. You can see my plasma cuts are sloppy...so it took me more time to fill in with weld.
Once you like the setup, weld the pipe permanently into the holes you prepared. You now have a nice recessed light pod setup.
I used old pipe I had laying around. Avoid using rusty/mill scaled pipe if you can, and use something shiny and new to ensure good welds, and a good clean setup.
Step 11: Lower Panels
If you run into the same desire, simply follow the same steps as earlier, and create some cardboard mock panels, to get a feel for what you want, in terms of size. Cut those panels, and tack them in place, doing test fits on the truck to get the feel. Use cardboard again to get exact angles for each piece, and work from the middle, out to the ends.
REMEMBER: EVERY PANEL YOU ADD MAKES THE BUMPER THAT MUCH HEAVIER!
Step 12: Closing Up the Welds
Start at the center and work your way out, putting final welds on. Remember, more welds can make angles change slightly, and "draw up" steel (depending on which side you are looking at). It's a good idea to weld a section, then re-test fit. Keep doing that until you've completely wrapped up all the welds.
Once complete, get out the grinding wheels, and clean up all the welds to prep them for paint. If you're lucky and using a gas Mig...you might have a cleaner time of it.
Step 13: Paint
I chose to use Rust-Oleum's Truck Bed Coating kit. I'd read different reviews, and it seemed like decent stuff for the money. You'll need to completely clean up your entire bumper, removing all dust, oils, etc.
After you have it cleaned up, in a WELL VENTILATED area, apply the Rust-Oleum bedliner using the roller. The material looks more textured when wet...but dries to a nice 'textured, but not TOO textured finish'.
Step 14: Wrap Up/Completion
Over the first week, keep a close eye to ensure that the bumper isn't TOO close to the bodywork, and that it doesn't contact the body of your truck as the truck twists over rough road/etc.
Also check the bolts holding the bumper on, a couple times over the first week. Make sure they stay TIGHT.
Have fun, and wear your safety glasses!!!