Bumper fab tips needed

[johnwaynejeep2]

I'm building my bumper and I need some fab tips from the experts. The problem is the angle at the front of the grill (I call it the beak). I cut my bumper in half and now I'm trying to fit it to this angle before I re-weld it but I'm not sure how to accurately match the angle. I don't have any tools for measuring angles.

I'm using 5 inch "C" channel for the bumper. I'm using 1/4 plate steel for the mounts bolted to the stock mounting holes in the frame. I cut the "C" channel into 2 equal sections but I can't hold the pieces stable enough to match the anlge of the beak. Even if I could I'm only eyeballing the bumper and this is not always accurate of course. My buddy suggested pounding a strip of sheet metal to the angle of the beak and then using that as a guide when I weld my bumper back together. It sounds good but I wanted to get some other opinions.

[shackwrrr]

use cardboard flat and draw the V shape on it and match it up then sit the C channel on the cadboard.

[johnwaynejeep2]

Thats so simple it's just crazy enough to work.

Thanks

[Kaiser]

Or, you could just take your bumper cross beam into a metal shop and have them bend it to the angle you want for something like $25 or so...
One less miter that could fail especially if youre using MIG or stick. "C" channel is fine, but why? I'll be looking at some 2x6 steel square tube. Additional cost is VERY negligible, but WAY stronger for this application. Rent a plasma cutter and place a hitch receiver for a multi-mount, and add some shackle tabs on there. Priced it all out a few days ago. About $60 in materials total.

[rstep]

Take two pieces of your 1/4 over lap the ends and drill and bolt them together.After you have them snug you can match them to the angle and tighten them up the rest of the way and hold it place aginst the bumper.You could also tac it in place on the bumper weld the 2 halfs together then remove it after you're welded.

[gmarblestone]

I am no fabricator, but somethink i was thinking about was taping some thread and a nail and dropping it from the areas you want to match. Then just line up your metal underneath and tack it together. Of course you have to be level on the car and the ground, but it seems correct. Again, i am just a computer nerd, no skills yet!

[orangecherokee]

best tips i've found is drink enough to get your creative juices flowing and your senses dull enough to not feel pain. next, never weld without a hood and third, when it's late and you screw up stop everything and start again tomorrow. :cool:

[Bama Burden]

best tips i've found is drink enough to get your creative juices flowing and your senses dull enough to not feel pain. next, never weld without a hood and third, when it's late and you screw up stop everything and start again tomorrow. :cool:
best advice I've heard around here in a while :thumbsup:

[case]

Get an angle finder at walmart or a lumber yard (they look like a big dull knife). The angle finders are real cheep. Use it to match the shape you want for your bumper. Then measure the distance of the opening on your angle finder, take that number half it (divide by 2) set your finder to that measurement and mark your ends.

[BRUTUS]

best tips i've found is drink enough to get your creative juices flowing and your senses dull enough to not feel pain. next, never weld without a hood and third, when it's late and you screw up stop everything and start again tomorrow. :cool:

All of these can and should be done at the same time too!

http://www.rebelrockrunners.org/gallery/d/13832-2/DSC00889.jpg

[fullsizejohn]

thanks for the pic brutus....reminded me of when i was young(er):D

[goldhammer]

But when you stop and start over the next day, beating the thing back apart with the BFH is a PITA with the hangover:D

[orangecherokee]

yeah it does suck but if you can remember what you did wrong then hopefully you won't make the same mistake twice. this happened to us building the cage. it got around 3am the second night and we spent time trying to accurately bend a piece of tube only to overbend it and screw the whole piece up. wasted time and materials.

we threw it down and walked out. :banghead:

[viscacha]

10°http://www.dakotacom.net/~jeepster/tipshades.gif

[johnwaynejeep2]

10°http://www.dakotacom.net/~jeepster/tipshades.gif

It's funny you should say that, cause I've been estimating the angle to be around 10°.

I got it worked out. I used the cardboard method and it worked really well. My bumper is exactly the anlge I want it to be at. Now I just need someone to hold the bumper in place over the mounts while I tac the mounts in place.

Did I mention I got laughed at?

I tried to weld the bumper myself and after about an hour of welding, grinding, thinking, welding, grinding thinking and finally more welding. I decided that the material was too thick and my welding skills were too bad for this. I took the bumper in to a welder and he started laughing when he saw the weld that I attempted. He showed me what I did wrong, let me watch him weld it correctly and only charged me $30. Cool guy, good sense of humor.

[xupe45tgp]

I don't think you drank enough before you started

[gmarblestone]

So what did you do wrong?

It's funny you should say that, cause I've been estimating the angle to be around 10°.

I got it worked out. I used the cardboard method and it worked really well. My bumper is exactly the anlge I want it to be at. Now I just need someone to hold the bumper in place over the mounts while I tac the mounts in place.

Did I mention I got laughed at?

I tried to weld the bumper myself and after about an hour of welding, grinding, thinking, welding, grinding thinking and finally more welding. I decided that the material was too thick and my welding skills were too bad for this. I took the bumper in to a welder and he started laughing when he saw the weld that I attempted. He showed me what I did wrong, let me watch him weld it correctly and only charged me $30. Cool guy, good sense of humor.

[orangecherokee]

I don't think you drank enough before you started

that's a definite possibility ;)

[johnwaynejeep2]

So what did you do wrong?

1) My welder is too small. I got a 120 volt Mig welder from Harbor Freight. It burns gaping holes in sheet metal and doesn't get hot enough to melt the bumper metal I was using; (5in "C" Channel, about 1/2 inch at it's thickest point)

2) I butted the metal together "I + I = II". I should have ground a "V" in the contact point "\ + / = V". the "V" allows the melted welding rod a place to sit. Otherwise I'm just adding metal to the surface and not getting any penetration.

3) I'm using flux core wire in my welder and I'm not using CO2 gas. CO2 gas will eliminate oxygen at the weld point. I have no idea why this is important but I guess CO2 gas makes for a better weld. Flux core wire is good if you're not using gas but using gas and standard core wire makes for a much better weld.

Bottom line: I cheaped out and bought a $150 welder. I'm sure it will work fine once my welding skills get better but I was trying to weld something that is really beyond the limit of my welder and my experience. Once I have the money I'd like to buy a Miller 235 or Lincoln 235. Both of these welders are fairly well priced (about $500 a piece) and they both have the option of using standard wire or flux core wire and they both have internal attachments for installing a CO2 gas canister if desired. For now the one I got will have to work.

BTW: the bumper is mounted. I still need to trim the ends and weld on some D-ring mounts and then paint it, but it's in place.

[bowtieman55]

:worthless:

[johnwaynejeep2]

:worthless:

I gotta do some work on it tomorrow so I'll take some pics and fight with my camera until I can get some pics up.

[matt thompson]

1) My welder is too small. I got a 120 volt Mig welder from Harbor Freight. It burns gaping holes in sheet metal and doesn't get hot enough to melt the bumper metal I was using; (5in "C" Channel, about 1/2 inch at it's thickest point)



I'm sorry to hear that, I had one of those pieces of junk, and I vow to never buy a cheap welder again...I ponied up the money to buy a millermatic 180.

[orangecherokee]

I have a Lincoln Electric 3500 Weld Pack. I give it 50/50 for satisfaction/PITA. The problem you're going to have is that with the welder you buy, you'll probably be able to burn hotter without the gas hook up. Mine will burn 1/4" easily with Flux but only 3/8" with gas. I choose not to run the gas and burn the poo out of the metal.

Another note, why were you using 1/2"?? Were you going for a cowcatcher frontend? All jokes aside I think that's a bit extreme.

[johnwaynejeep2]

The material is only about 3/8 thick but it gets thicker in the corners. My welder was able to tac it up but it took a lot of time. I had to turn the wire speed up and hold the gun in the same spot for about 20 seconds to get it hot enough to lay material. Even then I had to go through again and re-tac to make sure it held on the ride over to the welders shop to be properly attached.

Pics are up: http://new.photos.yahoo.com/johnwaynejeep/album/576460762383108435

I still need to trim the edges to match the bumper up to the corners of the rig a little better. Also I noticed the drivers side sticks out about 1/4 inch more then the pass side so it's a little cock-eyed. Aside from D-rings I also want to weld in some skid plates over the spring perches. It makes me nervous to think that my spring perches are left open to assault by rocks. Obviously I need to paint it too.

this bumper may be overkill for some people but I love overkill. Pushing over cows and knocking over trees is a must...not that I would of course ;)

[Crawlin_Chief]

I fab'd up a bumper for my heap this weekend. I used 4 feet of scrap 3x3 3/16 wall square tube that I dug out of the trash at work. 1 band saw, a 110 flux-core welder and a 12-pack later, success. It is all function, ugly and strong. I welded my tow bar brackets and added some extra plates on top to drill and tap for tow hook mounts. It is narrow because I like to keep the tires exposed. Kind of like a rock crawlin bumper...

Forgive the flat grey primer; it was all I had on short notice. I hope to mount a winch in the next few months and I needed a strong foundation.

http://i125.photobucket.com/albums/p55/crawlin_chief/Bumper2.jpg


http://i125.photobucket.com/albums/p55/crawlin_chief/Bumper1.jpg

[johnwaynejeep2]

I see you were able to get clean welds with the 3/16 stock. It's good to know that with practice I should be able to weld on SOMETHING.

Good idea with the tongue mounts on the front, I'll have to add some to mine as well.

[Crawlin_Chief]

I see you were able to get clean welds with the 3/16 stock. It's good to know that with practice I should be able to weld on SOMETHING.

I use a cheap 110 welder, but I use it flux-core instead of MIG. Don't get me wrong, MIG gives a clean weld with little spatter, but flux-core lets me get better penetration up to 3/16". Any thicker and you need 220.

Keep practicing and it will come. Make sure to bevel the edges on thicker metal to get good penetration. Also, beer is a must (helps me steady my hand...).