2nd Gen OEM style rear bumper build (basic tools only + plans, angles and measures)
Apr 5, 2011 | 08:18 PM
#1
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
2nd Gen OEM style rear bumper build and body rehab
After two rainy days of being stuck in the basement I thought I'd log in to share the progress and hopefully get some encouragement to get back down there tomorrow.
Vermont winters being what they are, the Runner is due for some body work, and a new rear bumper is more fun than the rest so I'm doing that first! Wanted something that kept the lines of the original, but with angles rather than curves and not too heavy (it's the work DD). Slightly limited also by lack of plasma cutters, pipe benders, plate benders, metal brakes, garage, etc... Took rough measurements of the stock one and this is what I came up with
Keeping the original lines meant not just going with a simple squared off design so I busted out the scientific calculator and went to http://www.purplemath.com/modules/basirati2.htm for a little trigonometry help. Never took it but the basics are surprisingly simple. Now I'm hooked, but that's another story! After some figuring came up with the plans - subject to change without notice
Also, in case my angles seem unclear, the degrees listed are measured as subtracted from the 90* end of the 1x1 workpiece like they would be on a speed square.
Next step for me was to draw the angles I would need, together with their complement. 61* and 29* e.g., coming from the same point. Easy way to set the T bevel, and also to check for square after cutting.
First came the base and mounts, parts for which are listed below the bottom drawing on the plans. I made 3 styles of these, each composed of two pieces cut at 59.5* to form the angle I wanted of 119*. Three of this type which also had the base cut at 61* to the tow frame. Two others, same but without the lower angle (less cutting), and four for the sides, which like the OEM will be a total of 9" high with a step-up.
Also squaring it up - since my base cut of 61* would kick the piece up at 29*, I placed it on the line I drew at that angle, and then the mating piece on top of it. This mate needs to be square to the ground so I used the speed square to adjust it so, lock it in with the magnet, and welded.
Yes, went with flux core, don't ask me why... But speaking of cutting, I first tried a grinder cutoff wheel. (Not even breaking out the acetylene for these cuts!) That was slow going as it was tough to keep the sides square to each other. Soon I caught an edge while trying to do one side at a time and the wheel disintegrated at 10,000 RPMs, right in my face. Good thing I obeyed OSHA and wore my safety glasses! Tried an abrasive blade in a cut off saw next, but it was a Craftsman (which I think must translate to "homeowner" in Chinese) and saw angles were way off, way slow, and a pain jacking up the workpieces to cut with a 7" blade on a 10" saw. Best method turned out to be a sawzall with the brandy new Freud "Diablo 'Liquid Metal'" blades. I made more than 50 cuts with one blade and can't even notice tooth wear, leaves Lennox in the dust. Polished up the angles with a grinder afterwards as necessary (usually was...)
With 9 of the base pieces out of the way, got into the meat of it with the step-up wraparound corners. This pic shows the three pieces cut and squared up on a carpenters square. And also my handy welder ground extension...
And lining up my 2" riser, plus the steel which will sit on it makes 3" of rise, like the OEM.
Getting technical... Lay my main bumper support on top of the (upside down) corner pieces, went to draw my 3-4-5 triangle for square, and realized that I had no point to measure from with my corner being as it was. So improvised by laying the carpenter square on the ground and butting it up to the speed square which I butted up to the main bumper span piece, making sure it was parallel to the span as pictured. Then measured the adjacent corner piece near and far ends off the square, adjusting until the measurement was equal. Worked like a charm!
So here's where I'm at. Haven't done a dry fit yet, or even brought it out of the basement. Slightly apprehensive since I haven't previously built without multiple trial fits as I go along but according to the measurements it should work! Famous last words, I know. We'll find out tomorrow...
Vermont winters being what they are, the Runner is due for some body work, and a new rear bumper is more fun than the rest so I'm doing that first! Wanted something that kept the lines of the original, but with angles rather than curves and not too heavy (it's the work DD). Slightly limited also by lack of plasma cutters, pipe benders, plate benders, metal brakes, garage, etc... Took rough measurements of the stock one and this is what I came up with
Keeping the original lines meant not just going with a simple squared off design so I busted out the scientific calculator and went to http://www.purplemath.com/modules/basirati2.htm for a little trigonometry help. Never took it but the basics are surprisingly simple. Now I'm hooked, but that's another story! After some figuring came up with the plans - subject to change without notice
Also, in case my angles seem unclear, the degrees listed are measured as subtracted from the 90* end of the 1x1 workpiece like they would be on a speed square.Next step for me was to draw the angles I would need, together with their complement. 61* and 29* e.g., coming from the same point. Easy way to set the T bevel, and also to check for square after cutting.
First came the base and mounts, parts for which are listed below the bottom drawing on the plans. I made 3 styles of these, each composed of two pieces cut at 59.5* to form the angle I wanted of 119*. Three of this type which also had the base cut at 61* to the tow frame. Two others, same but without the lower angle (less cutting), and four for the sides, which like the OEM will be a total of 9" high with a step-up.
Also squaring it up - since my base cut of 61* would kick the piece up at 29*, I placed it on the line I drew at that angle, and then the mating piece on top of it. This mate needs to be square to the ground so I used the speed square to adjust it so, lock it in with the magnet, and welded.
Yes, went with flux core, don't ask me why... But speaking of cutting, I first tried a grinder cutoff wheel. (Not even breaking out the acetylene for these cuts!) That was slow going as it was tough to keep the sides square to each other. Soon I caught an edge while trying to do one side at a time and the wheel disintegrated at 10,000 RPMs, right in my face. Good thing I obeyed OSHA and wore my safety glasses! Tried an abrasive blade in a cut off saw next, but it was a Craftsman (which I think must translate to "homeowner" in Chinese) and saw angles were way off, way slow, and a pain jacking up the workpieces to cut with a 7" blade on a 10" saw. Best method turned out to be a sawzall with the brandy new Freud "Diablo 'Liquid Metal'" blades. I made more than 50 cuts with one blade and can't even notice tooth wear, leaves Lennox in the dust. Polished up the angles with a grinder afterwards as necessary (usually was...)
With 9 of the base pieces out of the way, got into the meat of it with the step-up wraparound corners. This pic shows the three pieces cut and squared up on a carpenters square. And also my handy welder ground extension...
And lining up my 2" riser, plus the steel which will sit on it makes 3" of rise, like the OEM.
Getting technical... Lay my main bumper support on top of the (upside down) corner pieces, went to draw my 3-4-5 triangle for square, and realized that I had no point to measure from with my corner being as it was. So improvised by laying the carpenter square on the ground and butting it up to the speed square which I butted up to the main bumper span piece, making sure it was parallel to the span as pictured. Then measured the adjacent corner piece near and far ends off the square, adjusting until the measurement was equal. Worked like a charm!
So here's where I'm at. Haven't done a dry fit yet, or even brought it out of the basement. Slightly apprehensive since I haven't previously built without multiple trial fits as I go along but according to the measurements it should work! Famous last words, I know. We'll find out tomorrow...
Last edited by jbtvt; Apr 17, 2011 at 04:12 PM. Reason: Changed title to reflect body work involved
Apr 12, 2011 | 01:32 PM
#5
Banned
Joined: Mar 2011
Posts: 60
Likes: 0
looks good
Looks like a good start. Looks like you might be stick welding? maybe Fluxcore? Either way, with any welding, watch the warp issues. SMAW is my favorite welding process. Good luck, and keep the pictures coming.
After two rainy days of being stuck in the basement I thought I'd log in to share the progress and hopefully get some encouragement to get back down there tomorrow.
Vermont winters being what they are, the Runner is due for some body work, and a new rear bumper is more fun than the rest so I'm doing that first! Wanted something that kept the lines of the original, but with angles rather than curves and not too heavy (it's the work DD). Slightly limited also by lack of plasma cutters, pipe benders, plate benders, metal brakes etc... Took rough measurements of the stock one and this is what I came up with
Keeping the original lines meant not just going with a simple squared off design so I busted out the scientific calculator and went to http://www.purplemath.com/modules/basirati2.htm for a little trigonometry help. Never took it but the basics are surprisingly simple. Now I'm hooked, but that's another story! After some figuring came up with the plans - Top drawing is looking down, middle is looking straight on (the lower 2-3/4" slant inward), bottom left is side view of main bumper. Plans subject to change without notice Also, in case my angles seem unclear, the degrees listed are measured as subtracted from the 90* end of the 1x1 workpiece like they would be on a speed square.
Next step for me was to draw the angles I would need, together with their complement. 61* and 29* e.g., coming from the same point. Easy way to set the T bevel, and also to check for square after cutting.
First came the base and mounts, parts for which are listed below the bottom drawing on the plans. I made 3 styles of these, each composed of two pieces cut at 59.5* to form the angle I wanted of 119*. Three of this type which also had the base cut at 61*, and will be welded onto a 3" piece of 1x1 with a hole drilled in it to mount to the tow frame. Two others, same but without the lower angle (less cutting), and four for the sides, which like the OEM will be a total of 9" high with a step-up.
Also squaring it up - since my base cut of 61* would kick the piece up at 29*, I placed it on the line I drew at that angle, and then the mating piece on top of it. This mate needs to be square to the ground so I used the speed square to adjust it so, lock it in with the magnet, and welded.
Yes, went with flux core, don't ask me why... But speaking of cutting, I first tried a grinder cutoff wheel. (Not even breaking out the acetylene for these cuts!) That was slow going as it was tough to keep the sides square to each other. Soon I caught an edge while trying to do one side at a time and the wheel disintegrated at 10,000 RPMs, right in my face. Good thing I obeyed OSHA and wore my safety glasses! Tried an abrasive blade in a cut off saw next, but it was a Craftsman (which I think must translate to "homeowner" in Chinese) and saw angles were way off, way slow, and a pain jacking up the workpieces to cut with a 7" blade on a 10" saw. Best method turned out to be a sawzall with the brandy new Freud "Diablo 'Liquid Metal'" blades. I made more than 50 cuts with one blade and can't even notice tooth wear, leaves Lennox in the dust. Polished up the angles with a grinder afterwards as necessary (usually was
)
With 9 of the base pieces out of the way, got into the meat of it with the step-up wraparound corners. This pic shows the three pieces cut and squared up on a carpenters square. And also my handy welder ground extension...
And lining up my 2" riser, plus the steel which will sit on it makes 3" of rise, like the OEM.
Getting technical... Lay my main bumper support on top of the (upside down) corner pieces, went to draw my 3-4-5 triangle for square, and realized that I had no point to measure from with my corner being as it was. So improvised by laying the carpenter square on the ground and butting it up to the speed square which I butted up to the main bumper span piece, making sure it was parallel to the span as pictured. Then measured the adjacent corner piece near and far ends off the square, adjusting until the measurement was equal. Worked like a charm!
So here's where I'm at. Haven't done a dry fit yet, or even brought it out of the basement. Slightly apprehensive since I haven't previously built without multiple trial fits as I go along but according to the measurements it should work! Famous last words, I know. We'll find out tomorrow...
Vermont winters being what they are, the Runner is due for some body work, and a new rear bumper is more fun than the rest so I'm doing that first! Wanted something that kept the lines of the original, but with angles rather than curves and not too heavy (it's the work DD). Slightly limited also by lack of plasma cutters, pipe benders, plate benders, metal brakes etc... Took rough measurements of the stock one and this is what I came up with
Keeping the original lines meant not just going with a simple squared off design so I busted out the scientific calculator and went to http://www.purplemath.com/modules/basirati2.htm for a little trigonometry help. Never took it but the basics are surprisingly simple. Now I'm hooked, but that's another story! After some figuring came up with the plans - Top drawing is looking down, middle is looking straight on (the lower 2-3/4" slant inward), bottom left is side view of main bumper. Plans subject to change without notice
Also, in case my angles seem unclear, the degrees listed are measured as subtracted from the 90* end of the 1x1 workpiece like they would be on a speed square.Next step for me was to draw the angles I would need, together with their complement. 61* and 29* e.g., coming from the same point. Easy way to set the T bevel, and also to check for square after cutting.
First came the base and mounts, parts for which are listed below the bottom drawing on the plans. I made 3 styles of these, each composed of two pieces cut at 59.5* to form the angle I wanted of 119*. Three of this type which also had the base cut at 61*, and will be welded onto a 3" piece of 1x1 with a hole drilled in it to mount to the tow frame. Two others, same but without the lower angle (less cutting), and four for the sides, which like the OEM will be a total of 9" high with a step-up.
Also squaring it up - since my base cut of 61* would kick the piece up at 29*, I placed it on the line I drew at that angle, and then the mating piece on top of it. This mate needs to be square to the ground so I used the speed square to adjust it so, lock it in with the magnet, and welded.
Yes, went with flux core, don't ask me why... But speaking of cutting, I first tried a grinder cutoff wheel. (Not even breaking out the acetylene for these cuts!) That was slow going as it was tough to keep the sides square to each other. Soon I caught an edge while trying to do one side at a time and the wheel disintegrated at 10,000 RPMs, right in my face. Good thing I obeyed OSHA and wore my safety glasses! Tried an abrasive blade in a cut off saw next, but it was a Craftsman (which I think must translate to "homeowner" in Chinese) and saw angles were way off, way slow, and a pain jacking up the workpieces to cut with a 7" blade on a 10" saw. Best method turned out to be a sawzall with the brandy new Freud "Diablo 'Liquid Metal'" blades. I made more than 50 cuts with one blade and can't even notice tooth wear, leaves Lennox in the dust. Polished up the angles with a grinder afterwards as necessary (usually was
)With 9 of the base pieces out of the way, got into the meat of it with the step-up wraparound corners. This pic shows the three pieces cut and squared up on a carpenters square. And also my handy welder ground extension...
And lining up my 2" riser, plus the steel which will sit on it makes 3" of rise, like the OEM.
Getting technical... Lay my main bumper support on top of the (upside down) corner pieces, went to draw my 3-4-5 triangle for square, and realized that I had no point to measure from with my corner being as it was. So improvised by laying the carpenter square on the ground and butting it up to the speed square which I butted up to the main bumper span piece, making sure it was parallel to the span as pictured. Then measured the adjacent corner piece near and far ends off the square, adjusting until the measurement was equal. Worked like a charm!
So here's where I'm at. Haven't done a dry fit yet, or even brought it out of the basement. Slightly apprehensive since I haven't previously built without multiple trial fits as I go along but according to the measurements it should work! Famous last words, I know. We'll find out tomorrow...
Last edited by PadgettFabrication; Apr 12, 2011 at 01:33 PM.
Apr 13, 2011 | 03:25 PM
#6
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
Yeah, the warping caused some trouble on the wraparounds. It did occur to me, but I was tired and just tried to heat each side evenly and hope for the best. Wound up having to reheat with acetylene the next day and pound them out a little bit.If I could do it again I'd probably build a jig out of 2x4s. Do you pros have any easier solutions though? Thought about the thermal protective cream for example, but the joint itself would still get hot and cool causing issues, no?
Appreciate the feedback.
Apr 13, 2011 | 03:53 PM
#7
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
Progress
So for future reference, mistakes I've learned from so far are not to chance it with warping by welding freehand, and also the issue of multiplication of errors, so to speak. More on that one below.
Tore the stock bumper off with a fair amount of effort and broken bolts and am very happy with the weight comparison. I think that mine is actually lighter than the stock one right now. Of course, it still needs a few pieces and cladding in 20 ga sheet, but not bad at all weightwise.
Yeesh, that's what's been hiding behind the trim all these years. Looks like there's some body work in my immediate future...
Reinforced the tow frame with 1/4" plate where I'd be drilling through since this rig sees a fair bit of hauling weight.
This was my second issue, so far. I had anticipated some leveling would be needed, relative to the tailgate of course (not using the bubble here), but not the horizontal adjustments. My pre-fab pieces were off by just a hair, as horizontal width goes, but by installing them close to the center where I did, I essentially multiply the discrepancies as the bumper frame reaches it's outer edges. Obvious with 20/20 hindsight. Oh well, need to do some grinding and/or shimming. If I weren't cladding it I'd just fudge the difference in my welds but things need to line up for sheet.
Pulled the glass, regulator, and wiring, and welded in some 24 ga where rot had set in. Sacrificed smoothness of appearance for toughness with solid steel and welds ground smoothish, skipped out on body filler entirely. Don't need that cracking out every time I slam the tailgate down.
As it sits now. Cut metal from the entire bottom up to the fender. Will weld in some 20 ga for rockers tomorrow hopefully, rear quarter is a combo of metal and chicken wire where I could get away with it. Wheelwell will be wire welded inside the body, then matting and resin. Want to get this stuff squared away so I don't have to keep taking the bumper on and off.
Tore the stock bumper off with a fair amount of effort and broken bolts and am very happy with the weight comparison. I think that mine is actually lighter than the stock one right now. Of course, it still needs a few pieces and cladding in 20 ga sheet, but not bad at all weightwise.
Yeesh, that's what's been hiding behind the trim all these years. Looks like there's some body work in my immediate future...
Reinforced the tow frame with 1/4" plate where I'd be drilling through since this rig sees a fair bit of hauling weight.
This was my second issue, so far. I had anticipated some leveling would be needed, relative to the tailgate of course (not using the bubble here), but not the horizontal adjustments. My pre-fab pieces were off by just a hair, as horizontal width goes, but by installing them close to the center where I did, I essentially multiply the discrepancies as the bumper frame reaches it's outer edges. Obvious with 20/20 hindsight. Oh well, need to do some grinding and/or shimming. If I weren't cladding it I'd just fudge the difference in my welds but things need to line up for sheet.
Pulled the glass, regulator, and wiring, and welded in some 24 ga where rot had set in. Sacrificed smoothness of appearance for toughness with solid steel and welds ground smoothish, skipped out on body filler entirely. Don't need that cracking out every time I slam the tailgate down.
As it sits now. Cut metal from the entire bottom up to the fender. Will weld in some 20 ga for rockers tomorrow hopefully, rear quarter is a combo of metal and chicken wire where I could get away with it. Wheelwell will be wire welded inside the body, then matting and resin. Want to get this stuff squared away so I don't have to keep taking the bumper on and off.
Trending Topics
Apr 14, 2011 | 03:39 AM
#9
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
Right, we were discussing the EZouts, Poultney if I recall? Get that skidplate squared away? I'm in Mount Holly. Have to give a shout if I make it out wheeling over your way, think some trails in Ira/Middletown Springs are definitely on the agenda this season. Back to the body work for now...
Apr 17, 2011 | 04:40 PM
#11
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
Body work finished, - the paint
Starting to look like something out there. Got the rockers built first
The cheapest metal brake around, free actually, but works well. Lagged together two 4x4s along one edge, giving me about 3" of bending capacity. Aligned metal, tightened bolts, and pounded edge over with a 2x4 and hammer.
Worst beads I've ever laid. Why did I pick the windiest time of year to MIG weld upside down in my driveway? It's OK, they're getting rubberization.
Masonry/stucco mesh tacked up inside the body for the curves since I lack a metal stretcher. 24 ga on the doors, slight curves we can do.
Whole new door bottom done one evening and some patches the following morning. Guess which day had the 40 mph wind gusts...
This side went smoothly enough. Used the "gel" fiberglass resin, close knit matting, and bodoed over it, then body filler over that to fill in the pinholes.
Not so smoothly. Checked the weather, since I have no thermometer, which said it was 41, so went at it. Out of Gel resin so had a go with the regular stuff. Holy
words Batman! I had forgotten how much easier the gel was to work with.
Finally got it done but it wasn't setting, borrowed a heater to throw on it and it started melting off.
Had to tear it all off the next day, I will not take chances with temperatures again. Bought "lightweight body filler" to set the matting, and same procedure as the other side. Third time's the charm.
Rockers coated with rubber, estate sale freebie item! Loving it.
Tailgate finished product.
Planning on taking most of tomorrow off to finish the paint and start back in on the bumper frame, maybe even sheeting.
The cheapest metal brake around, free actually, but works well. Lagged together two 4x4s along one edge, giving me about 3" of bending capacity. Aligned metal, tightened bolts, and pounded edge over with a 2x4 and hammer.
Worst beads I've ever laid. Why did I pick the windiest time of year to MIG weld upside down in my driveway? It's OK, they're getting rubberization.
Masonry/stucco mesh tacked up inside the body for the curves since I lack a metal stretcher. 24 ga on the doors, slight curves we can do.
Whole new door bottom done one evening and some patches the following morning. Guess which day had the 40 mph wind gusts...
This side went smoothly enough. Used the "gel" fiberglass resin, close knit matting, and bodoed over it, then body filler over that to fill in the pinholes.
Not so smoothly. Checked the weather, since I have no thermometer, which said it was 41, so went at it. Out of Gel resin so had a go with the regular stuff. Holy
words Batman! I had forgotten how much easier the gel was to work with.Finally got it done but it wasn't setting, borrowed a heater to throw on it and it started melting off.
Had to tear it all off the next day, I will not take chances with temperatures again. Bought "lightweight body filler" to set the matting, and same procedure as the other side. Third time's the charm.Rockers coated with rubber, estate sale freebie item! Loving it.
Tailgate finished product.
Planning on taking most of tomorrow off to finish the paint and start back in on the bumper frame, maybe even sheeting.
Apr 20, 2011 | 09:15 AM
#12
Thread Starter
Registered User
Joined: May 2009
Posts: 578
Likes: 11
From: Southern NH
Final update for a while
Man, quiet group in the fab shop. Y'all scared of a little body work? Ran out of time for sheeting, gotta get back to work and kind of digging the spaceframe look so this is how it's going to be for a while. But first
Quick fix for the flapping gas cap. Tried melting bracket in at first, didn't hold so went with rivets.
Painted, Lower quarters black to match the rubberized rockers, body paint matched by Sanel Auto Parts, best around for it that I've ever seen.
Capped the ends
It'll still get sheeted one day most likely but looks good as it is and enough time spent on my own projects for a while.
Quick fix for the flapping gas cap. Tried melting bracket in at first, didn't hold so went with rivets.
Painted, Lower quarters black to match the rubberized rockers, body paint matched by Sanel Auto Parts, best around for it that I've ever seen.
Capped the ends
It'll still get sheeted one day most likely but looks good as it is and enough time spent on my own projects for a while.
Thread
Thread Starter
Forum
Replies
Last Post
dirtrider0129
Buying & Selling Advice - Feeler/Gauging Interest
10
Jun 24, 2015 12:24 PM
