Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

ATTN: Anyone that welds! Bumper Question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by dawson444, Nov 29, 2000.

  1. dawson444

    dawson444 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    1,034
    Likes Received:
    0
    Location:
    Raleigh, NC
    Well I am going to try to make a bumper this year in shop class, I am going for something like depdog's bumper (below).

    [​IMG]

    My question is, how would be the best way to attach the box tubing for the main part of the bumper to the mounting bracket I am going to make? I was thinking about doing something like the one on Steve's S.E.C bumper (below)

    [​IMG]

    I may also to the tube things on the side. Do you guys thing the weld will be strong enough to put tow hooks on the front to use to pull the k5 out and not break it? I also am thinking about adding a receiver to the front to have and maybe WAY WAY down the road I may add a Warn 9,500# winch, and I wouldn't want the bumper going anywhere. So do you if I was to use my shop teacher's Arc welder and weld the bracket shaped like Steve's SEC one to the box tubing it would be strong enough? I was trying to figure out a way to bolt the bumper to the bracket but I can't think of a way. Also 2 other questions:

    1. Any ideas on how to attach tow hooks on the front, like attach them to the bumper? Fredd???

    2. Is it a bad idea to close off then ends of the box tubing and use it as an air tank? WIll it like blow up if I was to hit something?

    Thanks!

    Dawson
    88 K5
     
  2. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    Re: Bumper Question

    I don't know enough about metal fabrication to comment on bumper building, but I deal with compressed gas and pipe everyday at work and would advise you NOT to use a square vessel to hold compressed air. There is a reason that every tank in the world that holds compressed gas is circular in shape: this design allows pressure to be evenly spread across the inner surface of the tank. Corners, even in the same strength of steel, are way weaker than a solid face and will split. There may be a way to calculate a safe pressure for a certain gauge of square tubing, but I've never seen compressed gas in anything other than a round tank.
     
  3. blazen91

    blazen91 1/2 ton status

    Joined:
    Sep 10, 2000
    Posts:
    1,738
    Likes Received:
    0
    Location:
    Hesperia, Ca 92345
    Re: Bumper Question

    I do agree with canmorek5, however I saw a Toyota in a mag that had one. You probobly will not have more than 75 to 100 lbs. of presure,so I think it would be fine, as long as you don't hit anything. But I do not work with compressed air everyday as does canmore.
    I would use a 1/4 in. plate bolted to the frame and build it off of that. Put your tow hooks right in front of the frame for strength.

    blazen91
    Protect the land FOR the people
    <font color=red>Not FROM the people</font color=red>
     
  4. dawson444

    dawson444 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    1,034
    Likes Received:
    0
    Location:
    Raleigh, NC
    Re: Bumper Question

    Hey CanmoreK5, what you think of running 75-100 PSI in it? You still think its a bad idea? Thanks!

    Dawson
    88 K5
     
  5. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    Re: Bumper Question

    I'm not sure what the pressure threshold of square tubing is, and I guess it would really depend on what gauge of steel you used and how your caps were welded on.

    Have you considered using actual pipe instead of square tubing? We use Schedule 80(Heavy Wall) pipe on our high-pressure pipelines, and the highest pressure pipe we have in our service area runs at 775psi!!! And we can safely use unthreaded regular wall pipe(Schedule 40) for pressures up to 150psi, though I would think you could easily double that figure and not exceed safe operating limits.

    My only concern would be how you could rig up a valving system to safely fill and empty a bumper like this. Everything would have to rated to withstand the pressure, and you may want to get a shop to set it up for you. Trust me, I've seen the damage that high-pressure release can do to a body.......

    Another bonus to the heavy wall pipe would be that you could weld accessories, like tow hooks, onto it without fear of creating a weak spot. Pipe may not give you the look you're looking for, but I can guarantee that it will outperform square tubing anyday.

    One last thing to consider would be how much volume you would need at a set pressure to give you the amount of air you require to meet your needs. The higher the pressure, the less volume required and vice versa.
     
  6. dawson444

    dawson444 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    1,034
    Likes Received:
    0
    Location:
    Raleigh, NC
    Re: Bumper Question

    Ok, I think I'll just pass on the air idea. However somone has to have more ideas on how to mount it. Please help me! Thanks!

    Dawson
    88 K5
     
  7. dawson444

    dawson444 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    1,034
    Likes Received:
    0
    Location:
    Raleigh, NC
    Back to the top.

    Dawson
    88 K5
     
  8. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    Re: Bumper Question

    First off your welcome to take any ideas off my bumpers that your like. few pictures where my bumpers are visible are on my page link below. I built it by having some 3/4 plate cut that I use as the uprights. This has holes for clevis's to be used. The Deck for the winch is 1/4 plate as is the lower plate. the bend on the lower plate is 45deg. Grad 8 5/8s bolts hold it to the frame though existing holes. the rear is simular but the center deck is 3/16 since it doesn't need to hold a winch. The ends are 4x4 but I haven't got around to putting in the fittings to take advantage of the tank space. I also put some cleats on the underside of the bumper to keep high lifts from sliding sideways when jacking. Got that idea when Dep, BigJbear and I had to jack up a truck to move it sideways and the top of the highlift allmost got pushed through a 5 gallon jerry can on the rack. Thankfully that was the one with water in it not gas. They knock down trees just fine.
    Second off one of the main reasons that most tanks are round is correct but there is further reason for this. They can use thinner metal to keep the weight down. I run my sliders (see link) as tanks. I'm using 4x4 inch box 3/16 thick wall. That thick is plenty strong to hold up to 150psi if your end caps have sound welds. They are always filled to 140psi (I'm not making air on the truck yet so I store enough to fill). I have slammed them so hard on rocks at Tellico that people have come running looking for the roll over (Depdog has been whitness). No problems at all.
    You will also need to put a way to drain them. I used a grade 8 3/8s bolt. I welded a nut over a hole I drilled of the same size. Put some plumbers dope or Teflon tape on the threads and your set with a drain. Make the weld EXTRA heavy if they are somewhere thay may get smacked.

    Diging it in the dirt with my K5's
    Grim-Reaper
    http://grimsk5s.coloradok5.com/
     
  9. blazen91

    blazen91 1/2 ton status

    Joined:
    Sep 10, 2000
    Posts:
    1,738
    Likes Received:
    0
    Location:
    Hesperia, Ca 92345
    I had two ideas today;1) was to use the round tubing already mentioned. 2) Deisels have cylinder tanks that they use to store air. The are not that big and can be cut down to the leigth of your choice. This may be something that can be mounted under the truck.

    blazen91
    Protect the land FOR the people
    <font color=red>Not FROM the people</font color=red>
     
  10. jcg

    jcg 1/2 ton status

    Joined:
    Mar 19, 2000
    Posts:
    660
    Likes Received:
    0
    Location:
    Rochester, NY
    One of my friends put a 3 gallon air tank under the rear floor right where it steps up for the back seat to use with his air system. He got the tank from a mail order but it's the same type you can get from Home Depot or Lowes. He also mounted a 3/16" plate under it to protect it if his drive shaft lets loose or some how a rock gets up there. Once I get my onboard air done I'm going to try and fit a 6 gallon in.

    Joe
    RIT Mini-Baja http://www.rit.edu/~bajawww
    Team Mudnuts http://www.mudnuts.org
     
  11. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    If you are worried about strenght you will be more than fine!
    I am using a 3.5" round tube front bumper with almost 1/4" wall. For the brackets that mount the bumper to the frame I used 1/4" plate welded to the back and the plate goes around at least 1/2 of the tube and is weded the whole way. The brackets are bolt to the frame suing the stock holes on the side(2) and the factory bolts. I also have a 1/4" plate going aross the top and that plate is bolted to the frame by the top factory bolt on top of the frame rail. I have a huge clevis mount welded directly on the front of the bumper and have yanked many truck with it with no problems. I added a winch last spring( HS9500i) and haven't had any problems using the bumper with that either.

    We used a stick welder to weld most of the bumper and used a mig to add to the main bracket weld. I have been abusing this bumper for 2 years now with no problems(knock on wood) :)

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  12. dawson444

    dawson444 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    1,034
    Likes Received:
    0
    Location:
    Raleigh, NC
    Thanks to everyone that replied, I got some good ideas of what I want to do, I don't think I am going to fill it with air. I might rig something up later on. I will post pics when I am done! Thanks again!

    Dawson
    88 K5
     

Share This Page