Canadian Disco 2 Build

R_Lefebvre

Expedition Leader
Yes.

I wanted to visually cover up the rear crossmember a little more than the 2x4 bumpers do. And I'd rather this bumper hit the rocks before that rear crossmember. I will be tapering up the ends for clearance on the sides. Starting from about the frame mounts, up to the ends where it will be 2x4. So it will give up little departure angle compared to the 2x4, in fact I doubt it will be any worse than a Greg Davis with the trailer hitch. I won't have any hitch hanging down or sticking out at all. I'll be making facility for the bolt pattern of a 5t Dixon-Bate tow jaw, which will also accept a piece of channel steel for when I need a large drop hitch, but will do nothing to the departure angle when not installed. So, it's more similar to a British LR hitch setup than an American style reciever tube.
 

SeaRubi

Explorer
maybe I missed it, but what are you going to do with the spare? With the increased departure angle, it seems like you'd want it mounted up quite a bit higher to keep from coming down on it?
 

R_Lefebvre

Expedition Leader
I've been thinking of that. At the very least, if I leave the tire on the door, I might weld some sort of steel extension underneath the tire for that reason.

But, I have been thinking of making a swing away tire carrier, just to get the weight off the door. I know it's not a huge deal as my tires aren't big, but since I'm already doing this, shame to pass up the opportunity. And I will probably go 32-33" next time I need tires. I wanted to make a tool mount on the door where the tire used to bolt to for a shovel and axe, plus it would have a CB mount, and the stanchion for my work lights.

I'd also like 2 jerry cans on the back. Not sure if they'd be on the same swing arm as the tire, or if I should do the double arm thing.
 

michaelgroves

Explorer
Nice job on the welding! And thanks for posting the build in detail - good info.

It strikes me you're planning a lot of weight hanging out far behind the rear axle - big spare, h/d bumper, swing-out carrier, tools, jerry cans... It won't be kind to your suspension. I know the options are limited, but keep in mind the Class 1 leverage effect!
 

R_Lefebvre

Expedition Leader
I don't think it's going to be too much weight. The tire was already there, the bumper won't weight *that* much more than the stock one, and a shovel and an axe... meh. The gas, ok, that'll weigh a bit.

Don't forget, because of the trailer, I won't be carrying much else in the truck at all. Only trail essentials. Tools and parts and survival gear.

Also I don't think I'm forging new ground here. Pretty common stuff on a Discovery, save I haven't seen many swingaways.
 

Red90

Adventurer
There is some overlap on the weld to the right. You need to make sure you are melting the parent metal.
 

muskyman

Explorer
There is some overlap on the weld to the right. You need to make sure you are melting the parent metal.

I saw that as well, I guess I would say get a welder with enough juice to do the job. He mentioned that he is tigging with a machine that at this setting is only running at a 10% duty cycle. I would say use that unit for welding the beer cans it is designed for and go get a simple cheap mig that is rated for the thickness of work you are intending on doing.

Lets face it you dont need to use a tig on a funny book simple rear bumper, in fact I would say its a waste of time to use one. Burn some wire and be done with it!
 

R_Lefebvre

Expedition Leader
That dark line is probably a figment of the poor photography. I'll take a closer look. I believe I was getting full fusion. The machine is capable of welding this as you can see on the tack weld. And since we're concerned about nitty gritty details again, it is 20% duty cycle now that I looked it up.

I certainly won't be buying a MIG welder at this time. I already tried that when I built the trailer and the Minister of Finance rejected my funding application. ;) I don't think a Miller 180 would even do a better job. I'd have to 212 and... just ain't happening right now.

If and when I have to, I have a Precision TIG 375 at work. I just prefer TIG over MIG. Especially once I get to the front side with visible welds.
 
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Mercedesrover

Explorer
There is some overlap on the weld to the right. You need to make sure you are melting the parent metal.

attachment.php


You're not getting full penetration on that weld. It's probably good enough for what you're doing but you need a lot more heat on that if you're trying to make a strong join.
 

muskyman

Explorer
That dark line is probably a figment of the poor photography. I'll take a closer look. I believe I was getting full fusion. The machine is capable of welding this as you can see on the tack weld. And since we're concerned about nitty gritty details again, it is 20% duty cycle now that I looked it up.

I certainly won't be buying a MIG welder at this time. I already tried that when I built the trailer and the Minister of Finance rejected my funding application. ;) I don't think a Miller 180 would even do a better job. I'd have to 212 and... just ain't happening right now.

If and when I have to, I have a Precision TIG 375 at work. I just prefer TIG over MIG. Especially once I get to the front side with visible welds.


I have to disagree , a correctly sized wire on a true 180 amp mig will burn in that kinda stuff in a single pass with no issues. I can't understand how you could like tig for simple stuff like that better. This isn't about pretty beads, it is about strength and being able to build the thing in a reasonable amount of time. You are also better off grinding the welds smooth before the thing is painted or powder coated so the part about welds you can see is BS as well.
 

R_Lefebvre

Expedition Leader
The specified Amperage for a 1/8" fillet TIG weld is 110-150 Amps. My machine is capable of 150 Amps. A 1/8" MIG weld required 160-170 Amps, and the 180 can only do 180. The 180 machine doesn't have a markedly improved amount of headroom. That's my point. I'll buy a MIG when I can afford a 212.

You have made the assumption I plan to leave the welds on the front unground, and that is incorrect. I will grind them. In my experience, the extra time it takes to MIG something is made up for in a reduction in the time it takes to clean up spatter, and a reduction in the grinding time due to the TIG's better ability to control weld deposition in-process. You deposit what you need and no more, quick grind to get rid of the fish scales, and you're done.

I'm not saying MIG is a bad process. But TIG has other advantages that outweigh the slow travel speeds, which is why I chose it.
 

R_Lefebvre

Expedition Leader
So as I said, the black mark in that photo is not overlap. It's a small amount of slag that came out of the weld. This is garden variety HSS, and sometimes you get that.

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Now, can we move on, or does somebody want to send this out for metalurgical anaylsis? Maybe I should have it cross-sectioned, micro polished and acid etched to check the grain structure?

Ok, so next I cut the backside open on the tubing in order to do the bend to match the plastic finisher:

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Then bend it over and tack it in place:

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And test the fit up:

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One side came out perfect, the other side needs a little more. Once finished, these will get fully welded. I'll cut the tube off at the next corner, and then taper the bottom.
 

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michaels

Explorer
Then bend it over and tack it in place:

attachment.php

for some reason, the first time i did this part i cut out an entirely separate piece. too bad i realized later i should have just done this same thing. :coffee:

it's looking good so far. i'm glad you noticed that the plastic finisher is angle in slightly like that. it just makes the bumper look that much better to follow that line.
 

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