Cab corners

[e015475]

Overlapped joints is just looking for trouble., Joints should be butt welded. If you don't the repair will telegraph through the paint, and it will certainly rust a lot quicker at the repair

Having a back up strip may not produce the finished product you want. The metal is going to shrink when you weld it. and to get it back to contour you are going to have to planish the weld to stretch the metal back out. This is going to be pretty hard to do with a backup strip in the way

Trim the patch panel first then use a sharp scribe to transfer the joint onto the old truck sheet metal. Cut to the scribe line with a cutoff wheel in a die grinder. Make adjustments with a sanding disk on the die grinder and make the final fit with a file. The more perfect the joint, the less metalwork you'll have to do.

Even if you are very experienced, cutting with tin snips will distort the metal causing it to curl at the edge.

Cutting the two panels together ensures that you are off at least the kerf width of the cutoff blade.

Do a precise scribe off of the patch panel and cut the metal square with a wheel. Grind and file to fit. Sneak up on the fit and take your time. The time it takes to make a near perfect fit, weld it and metal finish it is less than all the metalworking it takes to get a sloppy fitting joint to look ok with metalwork.

If you gas or tig the joint and have proper tacks, you can pretty much weld continuous bead, the weld that is proud of the metal will be easy to grind flush and there will be less work to planish the weld.

[MARTINSR]

Butt weld:

The BEST way to do it.

Overlap weld:

The "bestest" way to do it, if done properly.

The old story on it being a breeding ground for rust, I am sorry, it hit me one day EVERY CAR MADE from the mid thirties, EVERY SINGLE CAR IN THE WORLD is TOTALLY constructed with "lap" welds, The ENTIRE BODY on EVERY CAR!

These trucks, the ENTIRE thing is made of lap welds, what's one more going to hurt?

As long as it's done properly, and sealed properly, it will never be an issue.

There are places where they shouldn't be used, like across a huge panel. But on these corners, it's pretty straight forward.

Brian

[MARTINSR]

Originally Posted by e015475

Overlapped joints is just looking for trouble., Joints should be butt welded. If you don't the repair will telegraph through the paint, and it will certainly rust a lot quicker at the repair

Having a back up strip may not produce the finished product you want. The metal is going to shrink when you weld it. and to get it back to contour you are going to have to planish the weld to stretch the metal back out. This is going to be pretty hard to do with a backup strip in the way

Trim the patch panel first then use a sharp scribe to transfer the joint onto the old truck sheet metal. Cut to the scribe line with a cutoff wheel in a die grinder. Make adjustments with a sanding disk on the die grinder and make the final fit with a file. The more perfect the joint, the less metalwork you'll have to do.

Even if you are very experienced, cutting with tin snips will distort the metal causing it to curl at the edge.

Cutting the two panels together ensures that you are off at least the kerf width of the cutoff blade.

Do a precise scribe off of the patch panel and cut the metal square with a wheel. Grind and file to fit. Sneak up on the fit and take your time. The time it takes to make a near perfect fit, weld it and metal finish it is less than all the metalworking it takes to get a sloppy fitting joint to look ok with metalwork.

If you gas or tig the joint and have proper tacks, you can pretty much weld continuous bead, the weld that is proud of the metal will be easy to grind flush and there will be less work to planish the weld.

And I have to apologize, I am not attacking what you have said, it's all good info. I am just tossing out something here.

On the tin snips, using "offset" tin snips doesn't distort the metal. I use them all the time fitting pieces to butt welding near perfection.

Now I can't emphasize enough, I am not master metal worker who metal finishes something off to perfection without filler. I have, I have the ability to pull it off on easy stuff, I understand it. But I am not that guy, but I do get stuff done like a lot of guys can without those awesome skills. Just keeping it real for the most part, what you have laid out there is all good stuff to make something perfect, I am just laying info out there for the guy who hasn't got all the tools and years of skills to get something done.

Brian

[MARTINSR]

Originally Posted by Matt_50

Thanks guys, ok I think I'll use a strip behind the joint. Spray it with weld through primer too. I'll also try this every so many inches and then make smooth and go again.

Maybe the cutting and making it smooth between each tack will help keep me from over heating. I've noticed if I use cut off wheel vs grinding wheel it's not as hot.

I'll post back after I start to repair the inner.

I have to say, I got a pair of these years ago and they come in pretty handy.


https://www.eastwood.com/ew-panel-fl...yABEgL28fD_BwE

They have wider ones too, but I have used these for years.

Brian

[67GMCkid]

I bought a pair of those eastwood hand fired panel flangers 30 years ago, I found they got more use and are better suited as clamps.. Years ago I bought a Mac Tools air flanger yes it was a bit pricy but sure made things much nicer to work with..


If you flange a panel that gets wet or will hold dust/dirt make sure the lap is pointing down on the backside .
In other words make sure water will run over the joint not puddle into it...

These are what I have

https://www.mactools.com/en-us/Power...nd-Flange-Tool

[Matt_50]

I got some work done. I patched the inner piece. I'm actually very happy at how well that turned out. Bent the edge over in a vise, used pliers as a tucking fork and tucked and hammer and tucked and hammered. I followed you tube and it took a while but I was patient. I did overlap this repair slightly... it just seems to work so much better for me and my little flux core welder. I'll finish it up soon.

As far as the outer corner,...
I can understand why a lap could be a potential rust area... but it will be inside away from water and dirt and so far down into the corner hole it won't be seen. Plus I'll seal it like crazy.

[MARTINSR]

All you have to do is pull apart a lapped weld that looks perfectly clean to see it is RUSTED inside and you will understand. But the thing is, the ENTIRE cab is made of them, so one more isn't a big deal. Just be sure you clean that stuff up good, epoxy primer it, and seal it with a good seam sealer.

Brian

[Matt_50]

Your making me paranoid lol.

[MARTINSR]

Don't be, just get that sucker done and drive it with a smile on your face!

Brian

[Matt_50]

That's the truth! I had clicked on the mactools link, saw the price and ran away. I just looked at the price of the Eastwood one and now I'm wondering if I should go that route. How well do they work for such a rounded piece? Does it distort it some? At the same time, these corners I think are my last bits of sheet metal to replace. I suppose a strip behind weld is the same thing.

[MARTINSR]

Originally Posted by Matt_50

That's the truth! I had clicked on the mactools link, saw the price and ran away. I just looked at the price of the Eastwood one and now I'm wondering if I should go that route. How well do they work for such a rounded piece? Does it distort it some? At the same time, these corners I think are my last bits of sheet metal to replace. I suppose a strip behind weld is the same thing.

As you go around, yes there will be a little "lump"at the edge, but not real bad. Let me put it this way, I used that exact same tool on my cab corners.

Brian

[Matt_50]

Hmm.. well, I ask because my body working skills are sad. Only recently got a auto body set from Eastwood. Will I need to fix the area up a bit because of this lump? And just from welding I may need too... how do i even get a hammer down in the hole to pop a low spot out? Use some kind of spoon?

It's always nice to hear someone recommend a tool they used on same spot.

[Dan in Pasadena]

Originally Posted by MARTINSR

....so one more isn't a big deal.

Brian

But one less IS a big deal. At least to me. Doing it “right” to me makes a lot more sense than the “one more won’t hurt” logic.

[MARTINSR]

Originally Posted by Dan in Pasadena

But one less IS a big deal. At least to me. Doing it “right” to me makes a lot more sense than the “one more won’t hurt” logic.

Dan, the ENTIRE cab is made up of lap, pinch welds, the entire thing. And it's made "properly" so if it had one more part welded to it that same exact way at the factory, that would be a bad way?

If the lap weld is done properly, it's not like adding "one more bad thing" it's just like the factory built it! Hell, in 49 they welded on that strip for the windlace with a "lap" style weld, spot welded right over the metal, no butt, just laid it over the metal around the door opening and spot welded it, how dare them! So that 49 cab is somehow "done wrong" over the 48 cab which didn't have that windlace retainer spot welded there?


I just try to keep it real, not all of us can do the perfect job. And if that lap weld is done properly and cleaned and weld through primer is applied and then it's sealed off well, it's damn near as good as a butt weld. The truck get's done and they are on the road with a smile on their face!


Brian

[MARTINSR]

Originally Posted by Matt_50

Hmm.. well, I ask because my body working skills are sad. Only recently got a auto body set from Eastwood. Will I need to fix the area up a bit because of this lump? And just from welding I may need too... how do i even get a hammer down in the hole to pop a low spot out? Use some kind of spoon?

It's always nice to hear someone recommend a tool they used on same spot.

At your skill level, you are going to have a LOT more work from general welding flaws and what not than those little lumps.

You need to spend more time at fitting the panel and getting it into place. If you flanged it, and got it into place and lightly worked it smoother, and laid a flatter weld, you aren't going to need the work at the end to fix the rough stuff, it won't be there.

The time spent fitting it, grinding the edge a hair, holding it back up there, then grinding a little bit more, then holding it up there, then trimming a bit on the cab, then holding the piece back up there, twisting it a bit to make it fit, then planishing the edge of the adjacent panel to flatten it out so it matches the patch, then clamping it in place and finding that if you flattened out another area it would fit much better, then unclamping it and and flattening out that area and re-clamping it in place and finding it fits much better.....and on and on, THAT time spent is time VERY WELL spent.


Brian

[67GMCkid]

Originally Posted by Dan in Pasadena

But one less IS a big deal. At least to me. Doing it “right” to me makes a lot more sense than the “one more won’t hurt” logic.

The "right" way would be to replace the entire rear skin on the cab removing and replacing it the way it was done in the beginning.. Any thing else is a subjective repair..


If you lap it, it could rust. bare steel in the Lap

If you butt it, it could rust. you have burnt the metal welding

If you epoxy it, it could crack loose. if not prepped or mixed correctly.


The scenario goes on.
Do it the best way your skill set, budget and tools allow..


Chances are 30 years in the future 90% of the vehicles that are on this board will no longer exist..

[Dan in Pasadena]

I agree doing it the best way our skill set allows us.

BUT there are people that will or have used the “if-you-can’t-weld-good-weld-a-lot” method, the “sheet-metal-screw-a-patch-and-pile-on-the-filler” method and even the “just pile-on-more-filler-over-rusted-areas” methods.

No, I’m NOT saying lap welds are equivalent to these methods but I AM saying there are better methods and they lay along a continuum to butt welded & planished repairs. Why not use the best available method? Yes, if you can. If all that’s holding you up is not WANTING to take the time to make a tightly fitting panel, well I just don’t get it I guess.

[MARTINSR]

Originally Posted by Dan in Pasadena

I agree doing it the best way our skill set allows us.

BUT there are people that will or have used the “if-you-can’t-weld-good-weld-a-lot” method, the “sheet-metal-screw-a-patch-and-pile-on-the-filler” method and even the “just pile-on-more-filler-over-rusted-areas” methods.

No, I’m NOT saying lap welds are equivalent to these methods but I AM saying there are better methods and they lay along a continuum to butt welded & planished repairs. Why not use the best available method? Yes, if you can. If all that’s holding you up is not WANTING to take the time to make a tightly fitting panel, well I just don’t get it I guess.

You are very right Dan, if nothing else we need to learn to do it better, step up our game.

But that's the thing too, if someone is so limited, there is no way they can butt weld it, you know what I mean?

I toss out a lot of stuff on forums that is more about "getting it done" for everyone, more than "Make it perfect" as those of us who have the skills to make it perfect don't need any help, they just do it!

Those of us who have those skills won't listen to anything less than perfect, because they know how to do it better. Those of us who don't have those skills or tools can get something done doing it the "bestest " way I lay out. I just see it as better to get something done and move on, and get better as the project progresses than to be overwhelmed thinking it has to be perfect and never get it done.

And yes, as you said, some really do need to step it up a bit and it can make a big difference.

Brian

[Matt_50]

My initial question of asking if using a backing piece, a lap weld without the flanging, was because of my limited skills at welding and that I also have a flux core welder. I'm getting better all the time but I still burn through way to easy. I think that is just a common thing with flux core anyways.

I do want to get it to be as perfect as possible as far as fitment is concerned, and then have a piece behind it to help with burn through. The lap or flange seems like this is a great way to replace a bondo filled area with good metal with my limited skills.

Now, I would like to avoid a potential rust area. I though if it was sealed well enough I would be fine... also, if I can get a butt weld without a backing piece I suppose that would be great but how can I do that? I can't buy a new welder right now... how long would it take to be able to weld with flux core without burning through?

Copper? How do you use a spoon and still weld too?

[MARTINSR]

Originally Posted by Matt_50

My initial question of asking if using a backing piece, a lap weld without the flanging, was because of my limited skills at welding and that I also have a flux core welder. I'm getting better all the time but I still burn through way to easy. I think that is just a common thing with flux core anyways.

I do want to get it to be as perfect as possible as far as fitment is concerned, and then have a piece behind it to help with burn through. The lap or flange seems like this is a great way to replace a bondo filled area with good metal with my limited skills.

Now, I would like to avoid a potential rust area. I though if it was sealed well enough I would be fine... also, if I can get a butt weld without a backing piece I suppose that would be great but how can I do that? I can't buy a new welder right now... how long would it take to be able to weld with flux core without burning through?

Copper? How do you use a spoon and still weld too?

I was thinking a while ago about picking up some flux core wire to see what can be done to weld better with it, I personally have never used it in my life.

I have to say, I don't believe you need a new welder, most can be converted as they were made for either, look into that.

But practicing is all you can do, get the metal really clean, I don't know what you can do in particular with the flux core.

I know that with the MIG if you "tap" the trigger to make a tiny weld, a tiny piece of added metal there, you can "tap" it over and over building up some metal along the edge so you can then weld with more heat and not burn through because you added that metal.

Now mind you, you shouldn't have to do this! But if you have a little gap or something you can do that.

You could also get yourself a torch and gas weld it, a torch is cheaper than a MIG. I gas weld all the time, welded 5' long seams across my roof with a torch, it can be done.

Brian

[Matt_50]

Spent two hours getting it to fit, and like 10 min to tack it in. I bent a small screw driver over to make a right angle and sharpened the end. I reached in and marked the corner. Cut it well above the line and slowly cut it down to fit. Cut off wheel isn't the greatest but it worked pretty good. The new corner had to be adjusted a bit to fit the bottom door curve. Kinda through me off a bit but I made sure to do it slowly. Walked away a couple of times, did a little more, then another break. The last thing I wanted was to get upset and make a tiny stupid mistake.


I did use a 1/2 backing strip... primer, paint, tape, clamps, and blocks of wood lol all to hold it just right while I tacked it.

I'll smooth it, tack it, smooth it and so on until it is done. I'll post back with my progress. I also used the tap tap technique.. it helps.

[Indian113]

Don't be ashamed of that Job! Even the Pro's had to start somewhere. I just hope I can do that good when I start on my truck.

[Matt_50]

I'm pretty happy with it. No warpage, I'll keep going very slow maybe start on other side in between just to keep myself from going to fast.

[MARTINSR]

Be sure you clean that paint and or primer off more, inside and out. ANYTHING left on the surface is going to cause you welding issues. Did you use a Zinc "weld thru" primer on the inside? If you did, another BIG tip, spray the primer then leave it until the next to day to weld. It has to be FULLY flashed off and dry or it can cause issues with welding as well.

Now, a real "ecoat" primer or zinc "weld thru" can be welded through with a MIG (Metallic Inert Gas) but most anything else will give any welder issues. I personally have zero experience with the flux core so I don't know how it works with the "weld thru." But without a doubt not letting that weld thru flash off completely can seriously change the whole welding process for sure.

Brian

[8man]

Keep it up. You are doing good.