The Stovebolt Site Forums The Shop Area Paint and Body Shop What is the right order to replace sheet metal parts?

Hi Everyone,

Like so many others, my truck (1953 3100) has some rot that must be fixed. My floors, rocker panels and cowls (inner, outer and filler panel) all need replacing.

My question is: is there a sequence to follow for which part to replace first, second, so on? I remember reading in another post to do one side completely, then move on to the other side. I've also read that the fitment of the replacement parts isn't good, so I should expect to "tweak" them for better fitment.

I am a total noob in this area. All suggestions and comments are welcome! Thanks in advance!

Hard to give specific answer without study of what you are doing. You say "some rot". We don't know where and how much.
So general advice:
1. A cab is a 6 sided box. But two of the sides are mostly doors. Which are not doing too much to keep the geometry ridged. Especially when removed . The windshield opening is not much help either.

2. Since your work is low down, you do have reasonable support depending.

3. You are going to remove the floor and associated items like rockers, cowls etc. So therein lies the danger.

4. Visualize what removing something will do. Use common sense. Sequence the events by studying the box and maintaining the box. Doing a whole one side may still cause big trouble. Big trouble is: doors won't fit when you are done. Patch panels will not fit at all..... and they don't fit perfect to begin with.

5. Sometimes bracing is need on the inside of cab. Across from hinge to hinge pillar and across from latch to latch pillar. This would be maybe half way between the dash and floor. The bracing would depend on size of cutout metal, it's location and effect on geometry release. Other bracing is done at each door opening. From hinge "A" pillar to latch "B" pillar, to maintain the opening. Bracing is not always necessary. Example: putting in a patch in the middle of the floor.

6. The general rule is only repair rust. Only cut out what is rusted. Keep good metal. Don't use the whole patch if not necessary. Sometimes you use more of the patch and cut out good metal to reach a better butt seam resting/welding place.

7. You can't use bracing that only pushes outward or clamps inward. You have to bolt or weld them because you don't know if the box will expand, contract or twist.

8. Some folks use an "X" brace instead of one, each place. This may prevent twist when things are cut/box is "released".

9. We can't be specific because of all the variables with each project.

10. Search the internet for cab weld bracing, or floor replacement or rocker replacement.............lots of pics and advice. Study study study.........then do. Click

I’m not a body man by any stretch of the imagination but I think I would do one area at a time switching back and forth from one side of the cab to the other. To me that would help keep the integrity of the cab intact. Cutting out all the bad areas on one side would cause too much shifting for me. JMO

Bartamos,

I understand needing specifics from me to allow you to respond with specifics. Sorry for not being specific up front. I'm including a pic of the passenger side floor/inner cowl area as an example of what I'm trying to fix. The bottom of the outer cowl panel is rusted through, as well. There are similar issues on the driver side. One rocker has an elongated rust through hole, but most of it is intact.

I was trying to understand if it made a difference to do the floor first and index everything off of that or do the rocker panel and index off of that, etc. I'm guessing that the real answer is that there isn't an answer and each situation is unique.

What I did was bolt a piece of angle between the two bolts on the lower door hinges before removing anything. Also, when I removed the doors, I welded on bracing near the lower hinge level. I wound up replacing both rockers, a good portion of the floor, and the cowl panels.

Mike, I said it the wrong way. It's my fault not yours. When I said we would have to study it. I really meant we can't study the whole situation. Or at least I can not. I would have to be there. So I just gave a general. I did keep saying we don't know this and that too much, like it was your fault. Trying to say that kind of extensive sounding fix is hard to give a specific sequence and method of operation. Tried to get close without being exact. Probably some members can take a shot at exactness. I guess you can use what I did say, and that link, to get a feel. The rot looks pretty bad but not real abnormal. They make all the patches you will need. We haven't even discussed your welding skills and available tools and help from friends. Welding thin metal takes practice. Kevin has real good experience in AD cab repair.

Bartamos, it's all good. I did see the advice in your response, which I am taking onboard. I'm starting to formulate my strategy. The initial thoughts are that I do want a known good point as a reference or starting point. Even though the front part of the passenger side rocker panel is gone, the rear 3/4 of it is still there and in place. It seems to me that between that known point, the rear of the floor pan (which is intact) and the pinch seem between the firewall and toeboard, I should be able to figure out the proper alignment of the floor pan half. Once that is in place, I can go back and remove the rocker panel and under floor brace and then properly align those parts. From there, I would hope to figure out the alignment of the cowl parts (inner, outer and filler).

It all sounds good in my head.... But as they say, no battle plan survives first contact with the enemy.

I really liked the suggestion from Kevin about how to brace the cab. I'm going to try to do that before starting. And before bracing, I've got to develop some welding skills. So it would seem that I have some time to refine my battle plan while I practice welding on scraps.

You can follow along on my repairs on the link in my signature. Nearly all of the photos I took are in that Flickr link.

If you have vestiges of floor to A pillar junction, mark that for reference for the floor patches.

The Factory Assembly Manual is a good source for checking. It has a figure and some reference dimensions noted as Cab Welding Checking.

Good luck.

Make a bunch of drawings before you start. With many dimensions of everything. Measure from reference points that will remain as well as dimensions that will be lost when cutting starts. You can not have too many dimensions. Measure everything. You can draw pix or you can take pix and add dimensions. You need lots of pics also in case you forget what overlapped what or how something was attached, etc. Doing all that will save your butt months from now. As Kevin mentions you can add scribe marks or 1/8 holes thru two pieces or any method to add reference or alignment registration.

With hood hinges and door hinges, (and any other critical position component), I drill two offset holes in each hinge, far apart, thru hinge and mounting surface, (firewall/A pillar/etc.) before unbolting. Then on reassembly, I use two 1/8 drill bits as temporary guide pins, bolt it up and remove pins. This is, of course, if the hood or doors or whatever, has a nice fit to start with. Either way it gives a baseline location for the "was " condition.

I will limit my discussion to basics.
1) Take your time. You are about to eat an elephant. How? One bite at a time. Don't get aggressive and start cutting out a bunch of metal all over the place.
2) Do not lose the integrity of the entire door opening by removing too much of it at a time. It is known as the ring of death. It includes the rocker panel, hinge pillars, lock pillars, and the very top of the door opening.
3)Think in terms of you are about to start with a door and put the truck back together to fit that door.
Do not weld ANYTHING solid as you go. Use small self-tapping screws to temporarily hold everything together. This will give you the opportunity to make final adjustments prior to welding everything together once your doors fit perfectly.
These basics should save you many headaches.

As usual, Carl is spot on. I don't use "spot on" very often but it sounds English and they talk smart. So trying it out.

Very apropos when talking about "spot" welding panels!

I'm going through a similar effort as you right now. I've done some metal patchwork here-and-there before. But, never as much as I'm doing on this truck. Basically, replacing lower cowl, door pillar, kick panels and rocker panels. Looking for a respectable appearance but not show quality.

While I'm not completely disassembling everything at once as in Kevin's (very excellent) pictures, I am doing one side at a time. It would be great to have the space, time and resources required to yank the cab and do the work off the frame. I just don't have that type of setup. Plus, it helps to reference the other side if something unexpected comes up. And, I know I don't work very fast or have that long of an attention span. So, my intent is to work on a different portion each winter and drive the truck in the warmer months.

Here are some things I've found (with repeats of comments above) getting this (almost) done.

While I can't control what's rotted out and no longer there, I do try to limit the amount of metal I cut out to only what's rusted to get to good metal. For example, rather than replace the entire floorboard or outer cowl, I bought replacement panels and chop them up to make the necessary patches. In my case, some things had to be completely replaced (rocker panel). Limiting the amount of removed metal, I think, helps keep things in place with minimal bracing required. I know this isn't always possible. But, from your picture, it looks like you wouldn't have to replace the entire floor. Well, unless you want to!

As per the above, before cutting things up, try to get measurements or make braces or jigs to help line things up later. For example, I had to replace the lower door pillar to a point just above the hinge. Before removing that section, I drilled two plates to match the hinge mounting and welded a bar between them. When it came time to weld in the new patch panel/hinge, I bolted that jig between the top hinge and the patch panel hinge to make sure the orientation was correct. Made replacement easy. Of course, this only works if you have a place to start. I'm interested to see how the parking brake braces and hardware line up when it's done. All of that was rusted out with no way to get measurements before starting.

Next, unless you're using NOS panels/sheetmetal, not much is going to line up perfectly. This has been mentioned on this board a number of times. I couldn't agree more! One of the things I've tried doing that relates to your "where do I start" question is to prioritize mounting points and body lines. Then, work from there. I mentioned replacing the lower door pillar. Most important thing was to get the hinge mounting perfect. When I did that, I had to "tweak" the door pillar-to-rocker panel area. The other important area is the outer cowl. Getting the hood/door/fender gaps and fender mounting right is most important. If I need to "tweak" the hidden pieces between the outer cowl and kick panel, that's what I'll do.

My specific sequence was : rocker panel, floorboard, door pillar, outer cowl, kick panel, inner cowl. This made sense since I didn't need to replace too much of the floorboard. From your picture, I might have done the floorboard before the rocker panel? Like the outer and inner cowl pieces, there's a lot of contact between the two that can limit how far you can move things before you have to cut/weld to get things to fit.

Finally, keep references like Kevin's pictures at hand. I really wish I'd have seen those before I started. Really helps to see how things are supposed to go together. Manuals and drawings are good to have. But, there's something about an actual picture during step-by-step replacement that really helps me understand how things go together.

Excellent advice all around, but especially "beware the ring of death". Wish I saw 5 years ago.
I had less rust than you, so thought bolting to frame and replacing the absolute minimum would be fine. Everyone is right that you should brace and measure carefully and cut minimally to keep the geometry. But also, check some of your starting measurements against other trucks too. if the cab has rust and some "history", your geometry could be out of whack to start. Diistortions might not show up anywhere else, but end up with bad news at door fit time.

Taking the advice to heart, I've been doing some research and have come up with some questions. I've attached a page from the FAM, which I've highlighted a couple of areas. The questions:

1. The drawings make several references to the O line. I'm assuming that is the zero line shown at the bottom, followed by the 10 line, 20 line, etc. and accompanied by the corresponding grid on the side. Is this correct?
2. If so, then it looks like the top of the frame sits at the 10 inch line and the floor sits at the 11.88 inch line. That would indicate that the floor sits 1.88 inches above the frame. Is this correct?

This would give me the reference to use to correct the leaning of my cab, which currently leans to the right.

3. The drawing is labelled with "LD" at the end of the name. There is a corresponding drawing that looks very similar, but not exactly the same with the label "RD". I'm assuming that the LD is left and RD is right. Is this correct? Does it make a difference?

I know I'll have more questions along the way.... Thanks for everyone's patience with me as I try to figure this out!

LD is lefthand drive and RD is righthand drive.

Wow! I'd have never figured that out! So I can completely disregard the righthand drive drawing.

You are right on with your understanding of the reference "0" lines on that drawing. It's a valuable tool for putting a cab back together. Also helpful are a couple pages toward the end of section 1 of the FAM that give dimensions for the circled reference points on the drawing you posted. Those can used to establish the correct location of those points in reference to the "0" lines.

Yep, I had found the notes pages with the dimensions for the circled numbers. I should have mentioned them in my post....

Since the zero line is actually below any of the structure of the cab or frame, I'm guessing that point must have been on an assembly jig that the factory used. If so, it would make using a standard to measure those identified points simple...but I'm guessing. Since the frame top is at 10 inches, I can build a small wood box, who's top sits 10 inches below the top of the frame. That would give me the zero line from which to measure the other points.

I think you're probably right on the assembly jig. I can't think of another reason why the reference line would be below the body other than to eliminate negative numbers.

I just used the floor as a reference and did a little math to figure elevations of other points (or used other points to correctly position the new floor I put in.) But your wood frame would do the same thing, and eliminate the need to subtract any dimensions.

I did clamp a piece of angle on the front of the dash to use as a reference for the front cab support locations horizontally.

Update:

Well, If I want to brace the cab using the door hinge locations, I've got some preliminary work to do first.... Turns out that the brackets that the door hinges bolt to are shot...all over! Both top and bottom are either rusted out or the weld nuts have broken loose or a bolt was rusted in place and ultimately broke off or had to be cut. This leaves me in a bit of a predicament. Do I forgo the cab bracing, given that the cab has already dropped by almost 2 inches on the passenger side? Or, do I make new brackets and install them so that I can use the bracing strategy? Oh yeah, in order to do the latter, I need to learn how to weld first. As I mentioned earlier, that is a skill that I need to learn in order to finish this task. I just figured that I'd have time to do so while I was working on fitting the patch panels with screws. The question is do I learn to weld, make and install the brackets and then brace or do I just try to level the cab and go for it?

I'm open to the pros and/or cons of each approach. Sorry for the rambling nature. Please be gentle!

Mike, You have a VERY difficult task ahead. I will try, together with guys like Kevin who have done this on AD, to help you. You say you have no welding skills. You will have a LOT of welding. To be able to weld, with most of it relatively thin material, you will need to practice a lot and even after that you will screw up sometimes on the actual cab. Burn thru and etc. You also have a truck that seems to be falling apart, hard to find places to brace and maintain geometry. So is it better to find a better cab? You could possibly build a way out of whack cab. None of us would find any of what you have easy to repair. So give it a thought.

The drawing is coordinate dimensioning. Using Datums. X Y Z (0's). The Y is an actual feature (firewall). Now-a-days we use part features for all three datums. But this is not a part. It's a weldment drawing. The factory would most likely build a jig to locate and clamp each piece in place for welding.

I would recommend considering using/establishing actual features. For X you can use the actual frame or 2 x 3 metal rectangle bolted to the cab mount locations to create a new X datum at dimension 10. I guess you would simulate the thickness of the rubber and washers of the cab mounting hardware by using hard spacers and bolt the two datum rails to cab. You have the 11.88 minus the 10 dim to double check the set up to floor. You then use the top of the datum rails, or the frame if used, and subtract the 10 dim from each other dim given on the drawing. This would also establish what would be the Z datum in the left hand view, because they give the centerline of body bolt to "0" (Z datum). You would have that body bolt.

This would build a sort of jig. Easy to build easy, to measure from. You could set the two rails on "saw horse" type supports to bring it to workable height. I just don't know if the cab, the sag you mention and the rust outs would even allow the rails to be installed. That leads back to a better cab. I just fear that you are a beginner taking on a journeymen's job.
This is no way meant to disrespect you or discourage your can-do spirit. I can not analyze the cab well enough to give sound advice. Just giving you help in both ways of thinking.
I will think this thru better and make sure I said it right if you decide to build a datum structure.

Maybe using the drawing is not the way to go. Maybe bracing, using dims from other trucks and measuring your truck is the way to go. Maybe the drawing would just be reference. Again depends on the ability to brace and measure before starting on a sagging rusted truck. You keep running into more and more problems, but so did Kevin and others, and they pressed on with success.

Mike,

With all the hinge pockets rusted away, you have a major task ahead of you. There's really no need to brace using the hinge bolts, etc. You can tack weld bracing just about anywhere that has solid sheet metal.

With your description, I would hesitate trying to restore that cab. Like bartamos said, finding a replacement cab would be WAY less work.

Good luck to you. Once you get into it you'll be at least an adequate welder.

Park that cab in the back forty for another day in the future. Once you have developed welding skills which you will learn on the better cab which you now need to buy, you can dig that basket case out for your second truck project. Everyone needs at least two of these trucks. One daily beater, and one pretty boy truck.
I have 4 of them. One daily driven beater, one pretty boy truck on the road, another pretty boy truck almost on the road, and one other one, well, I just got carried away with that one.
You get my point. I hope.
If a guy is not supposed to keep buying these trucks, then why do I keep finding so many of them for sale?!

I think the experts have spoken.
If you cannot find a cab by September go to Fall Carlisle PA Swap Meet at the end of September.
Right up the road from you on I81.
Get there early on Friday at the latest.
There is a guy "up on the hill" that sells truck sheet metal he brings from the desert southwest. He usually has a cab or two.
They won't be perfect but well worth it.
Bring cash and expect to pay about $600.00 but carry more for other stuff.

Well, not the news I was hoping for... but hard to argue with. I guess I've got some soul searching (and internet) to do. Hopefully I'll get lucky and find a cab that will work for my current skill level.

Thanks everyone.

Just a friendly reminder, when/if you get another cab try to get one with a title. Moving number plates from one cab to another is a forbidden topic on Stovebolt.com. Discussion of such topics will get your thread deleted and a healthy rap across your knuckles with the Stovebolt ruler.

OK, wasn't aware of such a rule, but good to know. I guess I'll have to figure out what to do with the lovely people at our dept of transportation if I do get another cab.... I'm feeling a bit overwhelmed at this point.... Maybe it's best to sell this one and start fresh.... Got a lot to think about. Ugg.

So, after much thought, I've decided that I have nothing at all to lose in attempting to fit the patch panels to the cab. Worst case scenario is that I completely destroy the cab. In my mind, that's not much worse than taking it out to the back 40 and letting nature reclaim it is as iron oxide. I'm not going to worry about welding at first. This thread started with the question of whether or not there was a particular order in which to replace panels. It would seem that there is not. Given that the floor panels in the rear of the cab are good and their connections to the rocker panels are also good, I'm using that as my reference point. Using the drawing that I included earlier as a reference, I know that the frame is at 10 and the floor is at 11.88 or 1.88 inches above the frame. Adding bracing that is 1.88 inches tall between the frame and the floor will help me level the cab. I plan to work one side and then the other, going methodically. Once I'm satisfied with fitment, I'll attach with sheet metal screws and move on. If I'm successful, I'll either try to tackle the welding myself or if I haven't been able to learn enough while working on the panel fitment, I'll take it to a shop and have it welded for me. Getting another cab just isn't in my budget right now. I've been collecting the patch panels for a couple of years now, not knowing that the problem was as severe as it actually was. So, I've already got the sunk costs of the panels. This is a hobby for me, not a living, so I can take as much time as necessary to figure things out. I've owned the truck for 14 years already, and have never driven it. A couple of months more to get the bodywork done won't kill me. Don't get me wrong, though. The thought of putting the running engine into the truck and a milk crate for a seat and then driving around the neighborhood did cross my mind...but I'll try to keep the faith. Just like everything else related to this hobby that I took up, I'm learning it as I go. Ambitious or stupid...the jury is still out, but I have to have something to do in retirement.

Your thoughts are good. No one can say what is the best direction. What you are doing is actually necessary. You will gain all kinds of knowledge and experience. You can't get it from a book/internet pictures or advice from us. There are so many things involved with a restoration that doing it is the only answer. We all started where you are and are somewhere on the learning curve all the time.

Mig welding, in general, is user friendly. Use the pieces you cut off the truck to practice on. They are old metal and at the same thickness as the patches. Cut slits in them with a 1/16 wheel and weld them back up. The metal must be shinny clean on both sides of the piece. You have several processes to learn. Bracing, measuring, planning, cutting, grinding, welding, fixing blow thru, welder adjustments. It is a hobby and it is fun.........some days it's not fun until you get re-motivated, that's natural. Having something to do in retirement is exactly why I am doing it. You have no schedule, no boss, no hurry.

One of the mistakes newbees make is buying a whole bunch of stuff to get ready for the "rebuild". Wait until you are ready for an area, then buy. It only takes a few days now to get parts delivered. Stacking them all up and storing them, then losing interest or health problems, etc......is why there are so many basket cases for sale. Somehow, buying a bunch of parts makes some folks think they are restoring. Meanwhile the rust and mice eat it all up

Go for it. Now that you have made the decision, no more advice as to direction from us. Now just post your questions in the appropriate forum if you get stuck on something........anything.

I know you just asked for sequence, but is was good to brainstorm the overall cab. There is no sequence, as you have said. Just trying to keep the doors fitting and the cab in general shape. I know you get the picture. If something gets out of whack, just try to catch it and re-support. Prop it, jack it, brace it, bolt it, clamp it, lever it........whatever. Like you said: Use clamps and self tapping screws to mock it up and examine your progress. You can, for sure, tack weld it yourself when satisfied, then move to the next patch, as you also said. Knowing that you can reposition what you already did if necessary.

No complaints here. The discussion was good and I always appreciate honesty. Thinking and talking it through with everyone did help me understand the FAM drawing and how I could use it to complete my task. It also forced me to think things through from beginning to end, giving me a more complete game plan. All good things. I'm also trying to keep my expectations realistic. I know I'm a noob at all of this. Sadly for my truck, it won't ever win any beauty contests. Instead, it'll have to wear those patches and the remaining dings and dents as badges of honor for surviving, while one day cruising the streets of the burg. That's always been my goal: a mechanically sound, safe truck that I can drive and have fun with. Hopefully I'll get there one day.

I know that I recommended the "back forty strategy", but I will say that i commend you for taking on this cab.
My first cab was in worse shape than yours (if you can imagine that ). The truck sat in my driveway for 18 years before I got the gumption to start on it.
I would always say to myself that I would get to it once I had the skill level and finances to do it right. Guess what. The the Skill Fairy never showed up, so I got started on it anyway. It was a huge learning curve, but the journey was very rewarding
I got the cab done over a 2 year period, then stored it inside for 6 years. The truck is now approaching the end of the rebuild. It is a dandy looking truck which i am building for a guy who has more money than sense. He will have $50,000 in it before we are done.
I had zero skill when I started the rebuild. I have some now. I got an insane amount of help from this site. I could not have done it without the selfless, timely help from these fine folks.
Carl