Welding material selection/advice

[glenromanronin]

Hello, I have a 2004 FX4 with 120K that has rusted through one of the points where the shackle is held on the front left side (rear attaching point), I worked at a machine shop small machine shop for just shy of 10 years and am planning to rebuild and gusset my way to where I need the hole to be, my brother is a welder and is going to do that work. I thought to use 1/4" hot rolled but I have seen some people online saying 1/8" or 3/16" is good.

Also, I saw a post say not to weld vertically but in diamonds and not to go to sharp points.

The truck is not a daily (wife works from home and doesn't really drive so we can "share" her car) but I still want to do the best work I can. I'm hoping to keep it alive until I graduate school and can go fishing for something down south.

 

[Curious Hound]

Also, I saw a post say not to weld vertically but in diamonds and not to go to sharp points.

I believe this to be excellent advice.

Hot rolled or cold rolled? Probably doesn’t make a difference. I would use 3/16” or 1/4” thick material.

Inspect the rest of the frame really well. This spring perches are known to collect debris and moisture and rust out. You may prefer to harvest the rear frame section form a good donor truck and just replace the whole rear frame assembly.

 

[Uncle Gump]

They now have some frame repair patches... several out there.

Dorman 523-204 Rear Driver Side Frame Repair Kit Compatible with Select Ford Models https://www.amazon.com/dp/B01M586IE6?tag=959media-20

 

[Roert42]

10ga is fine, it’s close to the original frame thickness.

Vertical welds are fine for the original patch, but you will have to fishplate the verticals on both sides.

There is manual from ford on how to modify truck frames. Not exactly one to one, but the basics are the same. Excellent source for learning to word a truck frame.

 

[alwaysFlOoReD]

Fordbbas. Com used to have a good article on welding frames.

 

[lil_Blue_Ford]

1/4” plate is way too thick for Ranger frames. Even 3/16” is way too thick (I had a mending plate made of 3/16” and it was annoyingly thick). 1/8” has become my preferred patching material for Rangers. Ideally you want no straight vertical patches and no sharp points, corners should be 45* or less.

For the rear spring hangers spot, buying the mending plates (Dorman and a few others make them) will work just fine. I’d definitely make a close inspection of the rest of the frame though. Rear frame section and especially the crossmembers in the back and the down slope of the frame next to the gas tank like to go. Bottom of both rails under the cab and around the front shocks and control arms are common too. Frame section behind the catalytic converters likes to rot out and it’s often hard to see.

 

[Roert42]

I second this. Expect more issues then you can see. Plan to strip the entire frame from the cab back minimum. if there is a hole behind one spring hanger, there probably is one behind all of them. Once you start banging on stuff with an impact gun and wire wheeling the rust off to paint you will find more spots where it's very thin.


I've attached a pdf of the manual on frame welding and extensions.

 

[Eddo Rogue]

+1 what these guys said. Good advice here.

I would use cold roll if avail but its not a big deal. Just make sure material is clean and there is some groove at the joints for the weld to fill in. 1/4" def too thick.

Definitely spread some tacks around before burning in complete beads. The more you spread out the heat, the less warpage after weldings done.

 

[4.0blue98]

Did this a couple years ago with the Dorman patch panels. Nice stuff and plated the vertical weld with a diamond shaped piece of 1/8". Still need to do the passenger side but the shackle bracket actually broke off on the driver's side...

The prefab pieces make it real easy to bolt all the shackle and bumper bits back on.

 

[glenromanronin]

Thank you all, and as much as I am almost too ashamed to admit it, I typed shackle knowing full well it is the front left lower control arm rear bolting point.

I picked up a piece of 3/16x7x28 hot rolled today to start to piece together and bridge to the point I need to get to. I also reserved a welder at a local rental place (our millers board just went) so my brother can come and just start as soon as we get the machine Saturday.

I will upload some pictures tomorrow of my situation and progress

Lastly, I may have misunderstood a warrant officer I was speaking to but can I/should I use rust barrier between layers when I am adding material?


@ericbphoto @Uncle Gump @Roert42 @alwaysFlOoReD @lil_Blue_Ford @Eddo Rogue @4.0blue98

 

[alwaysFlOoReD]

You can use a spray can of zinc weld thru primer.

 

[alwaysFlOoReD]

FYI:
Zinc fumes are not good for you. Make sure to not breathe them while welding. Not that any welding fumes are good...
Also, chlorinated brakleen creates phosgene gas when welded. Don't breathe that either. I believe its the same as mustard gas used in the WW1. Once evaporated its fine to weld.

 

[Roert42]

When you weld the fish plate on top the patch, if you use a weld through primer, it will mostly burn off. Not much effect after welding.

I believe a weld through primer is mostly intended to protect the metal before you weld it.

 

[alwaysFlOoReD]

When you weld the fish plate on top the patch, if you use a weld through primer, it will mostly burn off. Not much effect after welding.

I believe a weld through primer is mostly intended to protect the metal before you weld it.

That could be. But I look at it as better than nothing.

Edit. As long as the fish plate is fully welded on the perimeter, then no need for weld thru.