Rear Bumper Build

[gilleland53]

So here we go. The weld shop at work slows down a bit this time a year and we happen to have some scrap (drop) tubing around and a welder chomping at the bit to burn some metal.
So the cruiser is getting a new bumper. 4" sq. X 3/16" tube steel with integrated hitch receiver and d-shackles. The tube is cut and shaped. I need to source the receiver tube and design the bracing. This will be replacing the stock bumper, rear cross member & draw-tite hitch. I plan on running two swing arms.

Questions:
1. Spare tire swing arm on the left or right. (Planning two arms for the spare tire and a couple fuel cans).
2. It will all be sealed up. Should I use it for compressed air or water?
3. Spindle / hinge hardware recommendations for the swing arms.
4. Powder Coat or Bed Liner
5. Any other recommendations.

I plan on using the bumper wheelin and dragging timber up at the property.

Hopefully I can get started on a front bumper soon as well.

1988 FJ62 - bone stock & begging for new springs.

 

[Spudman]

Hi mate

Looking forward to this, can you please put up some measurements as you go

I would put the swing away carrier on the passenger side so that it swings away from traffic, I could have said left side, but some people drive on the wrong side of the road

 

[Sethro60]

Your spare tire will create somewhat of a blind spot, I would put it on the drivers side. (opposite of mine.) I would not put water in my bumper unless it was stainless steel. I've always loved the air storage idea.

 

[NolanFJ60]

I would not store water in a steel bumper- compressed air would be cool. If you had an onboard compressor hooked up to your bumper you could run air tools. That would be sick. Here's a link for some spindles-

http://www.ruffstuffspecialties.com/catalog/STIRES.html

 

[ntsqd]

1) On the driver's for the reason stated.

2) Neither. Square or rectangular tube is not a good choice for a pressure vessel and steel isn't a good choice for water (if you do compressed air it will have both in it).

3) The typical 1" 'trailer spindle' will break from fatigue, it's not big enough for single shear. Buy two 1" ID flanged oilite-bronze bushings from mcmaster, put them top and bottom in a tube thru the bumper tube, build the swingers to pick up a pivot pin top and bottom (double shear), and use some 1" shafting for the removable pivot pin. If you weld a flange on the pin you can bolt it to the top or the bottom of the swinger so that it pivots in the bushes rather than in the swinger's tabs, and then weld a weldable shaft collar to the other tab so that you can easily clamp the pin there too.

4) I just painted mine.

5) Use a De-Sta-Co type latch (search mcmaster.com for them), buy it pretty big so it's easy to use not because you need that much holding/clamping power. I bought mine with the secondary lock on it. Orient the latch to draw the end of the swinger either with a 'V' on it into the bumper tube (what I did) or the end of the swinger tube into a 'V' on the bumper. Arrange the loop of the latch to pull directly into the corner of the 'V' so that when latched this part also supports the load on the swinger.
Since pictures mean more than words, a pic of mine still in process:

 

[gilleland53]

Thanks everyone. I think I will keep the bumper sealed up and forgo the air/water idea. As for paint, we run a ton of stuff through a local powder coater. I think I can strike a deal with him. I really like the ruff stuff industries spare tire spindle. I picked up the tube stock for the receiver yesterday and hope to get it welded up this week. I will post pictures of the progress. And dimensions soon.

 

[ntsqd]

Your PC place may have trouble in their oven if there is no vent, but keeping it sealed enough that there's no place for mud/snow/ice/carp to build up is a good thing and something that I wish that I'd done with this front bumper:

The back-side is open and is a pain to clean out.

 

[NolanFJ60]

2) Neither. Square or rectangular tube is not a good choice for a pressure vessel and steel isn't a good choice for water (if you do compressed air it will have both in it).


I agree with what you said, but at 3/16" thick I doubt it would ever bulge under pressure which would probably never exceed 150 p.s.i. And you could put a water trap filter in the air line going in to the bumper.

 

[ntsqd]

Have you ever seen a ASTM pressure vessel made from anything but round with rounded end caps? There are extremely good reasons why you haven't. Also, any pressure vessel over 125 psi, pressurized or not, on a vehicle is subject to DOT rules. Not that they're likely to do anything, but know that it could happen.....

 

[gilleland53]

Almost ready to weld.

 

[JohninFla]

That's sexy right there. Simple and clean.

 

[gilleland53]

Should be welded up tomorrow. I am working a home show this weekend so it probably won't get bolted in place until next week.

I am still looking at what to use for the spate tire and gas can swivels. (Can't make up my mind).

 

[gilleland53]

All welded up. Ready for paint (temporary until I build the swing arms...blast and powder coat after that).
May have this bolted up tonight.

 

[JohninFla]

Nice work! I like te fish bone supports to the trailer hitch. Is your frame crossmember rusted out?

Make another one and send it south!!!

 

[ntsqd]

How do you access the hitch pin holes?

 

[woytovich]

Is that your receiver tube or are you planning on welding a tube unto that square hole/tube?

If that IS the tube how are you going to pin the hitch into the tube?

 

[woytovich]

How do you access the hitch pin holes?

You beat me by 1 minute!

 

[gilleland53]

I am pretty stoked... It's coming together.

The hitch pin is located 2" further north than normal and will not work with some inserts. I still need to add tabs to the inside for safety chains.

The receiver tube is welded through the bumper tube then sanded smooth. The receiver tube was chamfered and filled with 1/4" of weld.

My stock cross member is fine. It's going in the rafters with the stock bumper. I will be removing the body mount perch rivets and bolting thru the new assembly, frame, and body mount perches.

Test fitting later tonight if I can clear a spot in the garage (Sacramento is a little rainy right now).

Thanks for the input guys!

 

[gilleland53]

I am a draftsman by trade. I will revise the CAD drawings when it is complete for anyone who likes or wants to improve on the design. I can send any native autocad format or sketchup.

Following up on the powder coating conversation... At work we use a zinc paint / primer that is intended to be used as a base for powder coat. It's pretty crazy stuff and adds a barrier between the steel and PC. I cleaned and primed the bumper this afternoon. I plan on running it like that until I can send it over to the PC.

 

[JohninFla]

Zinc base coat, (epoxy 2part) is what we use on our equipment intended to live outdoors in harsh environments for 20 years. We end up with 250 um of paint in three coats. The barrier between the oxygen and the steel is what keeps that rust off.

If you do lay it out, I wouldn't mind a copy in autocad or whatever. I have my own bumper materials in the garage right now, I just need to be home long enough to actually start cutting and welding.

It looks great, keep it up!