The Stovebolt Site Forums The Shop Area Paint and Body Shop Learn how to "Cutt and Butt"

We have all used several methods of doing a patch panel repair. Make a template. Cut out the rust, make a piece to fit by scribing or copy the cut out piece. Cutting both pieces at once. All kind of methods. Here is another method.

1. Place a fabbed metal patch or donor patch or an aftermarket patch or a piece of an aftermarket patch over the rusted area. A little bigger than the rust area. Maybe 1/4 or so bigger all around. We don't want to cut too much good metal away.

2. Spot weld this piece to the existing body metal. Just a few. Spot weld the corners and spot from there, 2-3 inch spaced spots.

3. Use a thin angle grinder or die grinder to cut along the edge of the patch. Start at a corner. Go about an inch or two one way, cutting the corner spot. Then start going the other way and cut thru the first spot weld. You are NOT cutting the patch. Just the body. You are using the patch edge as a cutting guide.

4. This distance between initial spots will vary depending on the size of the patch as you will see with practice.

5. IMPORTANT: Cut at a 45 deg angle. Tilt the cutting disc top away from the patch. Do not cut with disc perpendicular.

6. Stop cutting after you have cut thru the first spot weld. You will then be able to push down on the patch and the body in that distance you just cut. This will flush up the patch to the rest of the body in that area. The patch will not fall thru if you have cut at a 45. By cutting all the way around at once or the other method of cutting both pieces all around at once will cause you to lose control of the patch and cutout. Then, as you know, will require you to hold and align the whole patch in place with magnets, tape, clamps............ This method requires no clamps, no magnets no tape, no alignment. It is a one step patch technique. Cut a distance, flush up, weld....cut a distance, flush up, weld.......

7. Cutting at the 45 prevents the patch from popping thru and you having to lift it back up and push down over and over to get a flush fit. The rusted piece will act as a spring and will begin to bring the patch down, and in place, as you go. The 45 also prevents welding the rusted piece back on. Forces it to fall away gradually. So to continue....... after you have made the first cut thru the first spot weld and have pushed the patch down gently and flushed it, spot weld again, back upstream as necessary to keep the patch flush in the area you just cut. You are then welding the patch in. Then keep going to the next spot weld and do it again.

8. Eventually you will end up with a good fitting patch and a rusted area that will fall away at the last cut.

9. If you cut too far at once you may reweld the rusted/dented piece back on again. Don't do that.

10. The other advantage to cutting at 45 is it creates a "gap" that is sort of self backed. To help prevent blow thru. You will notice that before you weld the gap, that if you take a disc and try to slide it perpendicular thru the gap, it won't go.

Of course the big rule still applies when doing final welding. NO beads, only spots, far apart, cooled with air. go slow and then go slower than that. You will see that, depending on the size and the ability of the patch to drop down as you go, will dictate how far apart and how many initial spot welds are necessary. This will take a few practice sessions like anything else. Feel free to adapt any ideas you have into this, or change anything you want to suit yourself.

Now you can "Cutt and Butt". Try it, you'll like it.

I watched a youtube video of that method. It would work pretty well on mostly flat panels, but if the area that needs to be patched is rounded (such as a cab corner), you can't get a good fit of the patch panel over the original. But I suppose you could work it in as you go.

But worth trying.

Have you folks ever tried using a handheld flanger and silver-bearing solder like Harris Stay-Brite? It melts at very low temp, works on ferrous metals just fine and is stronger than brazing. My experience has been on flat panels or simple curves (like fender bottoms) it can turn hours of work into minutes of work and it is easy to get the hang of using it. Plus all you need is the flanging tool, some sandpaper, solder and flux and a propane torch. Measure and cut the old part out carefully using a saber saw and fine metal blade, fit and flange the patch piece carefully all across/around the joint area, set in place, tack solder at ends and the middle and then run the solder joint from one side to the other. You can do compound/complex curves this same way, but you will have to use a narrow jaw flange tool for tight turns. You can easily make your own narrow flange tool from an old pair of vise grip pliers. Soldering is notably faster than welding and there is a pace at which the work behind you cools at just the right speed...and that's part of getting the hang of it. If you're careful with temperature, you can also say goodbye to warping. I should also mention solder is easily sanded and in some cases you'll only need a very thin layer of filler putty (if any) when you're finished.

If you are talking about a lap joint, many of us would be totally against that. Invites rust, entrapment, bubbling of paint, but haven't tried your method. Trying it would be too risky due to the cost of a paint job. Butt weld is preferred by me in most cases on a body.

Jon's method would work to avoid rust entrapment as long as you got the solder to fully fill the lap joint, although Robert posted a video about having a ghost line in the paint from a lap joint due to the change in base metal thickness.

I haven't had a problem with rust or paint bubbling at all. You know, if you get the pieces to fit right, solder follows heat and will fill up even wide gaps automatically. However, those pieces have to fit correctly no matter if you're welding or soldering or brazing. Just a different way to skin the cat. I worked as a commercial welder in the late 60s, by the way. Quick way for a young man to become an old man in the miserably hot weather we get in Dallas.

You can also usually put the flange backwards...that is to say flange the old metal (the part you're saving) and let the patch panel fit forward into that flange area. If you're concerned with drainage, let common sense prevail and do it that way. In that case the flange will be a rear overlap to the patch panel and any water coming from above will run right over your joint. I've done it that way plenty of times, but generally I like to flange the patch panel since you can move it around easier.

Another thing I do is to buy some water-based black satin X-O Rust paint and coat the back side of any part that I can. If it is a door, I'll tape up the drain holes and pour about 1/4 of a beer can in there. Tilt it all directions, letting that paint cover everything. Be certain to let it run into the seams well. I use that paint because it dries fast but it remains flexible so it doesn't crack down the road. It sort of reminds me of liquid caulking compound. And I've mentioned this here before, but I've also used J-B Weld. Especially the Kwik-Weld stuff they make now. You can mix it up, apply to both the flange and the panel, join them and hold in place with some high quality masking tape. It will set up in about 5 minutes and cure in about 5 hours. Then you'll have it done without using any heat at all. I repaired my truck where the roof cap joined the pillar on the passenger side in 1978 and you still can't tell anything was ever done.

Hey, I'm just giving a guide to a method. That's the Topic. Not looking for everyone's other methods. Start a post, aye? I know there are a Brazilian other ways. Jeez.

Appreciate the technique Bartamos. I'm saving in my permanent reference file.

I need to replace an area of passenger-side floor butting up to vertical kick panel. Any advice for that?

Gotta have pics.

A pic is attached. When I got the truck this rusted out area was covered by aluminum that was riveted in place. Some of the rivets are still visible. Luckily the support directly underneath the floor is still sound.

Thanks

Have you done any patching before? If so where? You have a welder and can mig weld? Whenever I get ready to do ANYTHING, I check stovebolt and the internet. I have done lots of various repairs and patch panels. Doesn't matter, I always study for a long time before starting.
I always try to find David Welch from Brothers trucks. Good videos by a regular guy who is like you and I. I may watch other homemade youtubes. I do not watch the "Hollywood" guys like Kevin Tetz or Stacy David. Here is a video from David Welch/Brothers that will help you. (third video)
David Welch started making videos at his house in CA. 20 years ago and Brothers picked him up.

The important parts of your repair are:
1. To understand the original structure that will hold the patch piece.
2. Cut very carefully and small areas at a time, to eat into/cut off small pieces to save the inter structure. Save it to look at and take pics and measure to see how to rebuilt it before you cut it off, or save it so as to leave it and use it to attach the new patch piece.
3. You can see in the video what pieces you will need to buy. You may only use a portion of the patch panel. You may need two patch panels. You may use a portion of a patch panel and make the rest.
4. Life is better if you buy a patch panel, already shaped.
5. You seem to have floor and kick panel rust. If some piece is flat, use a flat area off of a patch you don't need or a piece of sheet.
6. It's nice to build it back the way it was instead of inventing your own method/design.
7. Think about every cut really hard before you cut. Try to think on how you are going to provide the proper piece to weld or bolt it to.
8. You may get into cutting on the A pillar hinge post, so don't let truck sag or distort the door opening or fender mounting, etc.

Other folks here may have other/better advice.

Thanks for your advice. No this is all new to me. I do not have a MIG yet. I have been reading and learning about it, so I think I have an idea on what MIG to buy and how to approach learning. I am going to have to invest in a lot of practice before I do any real work.

I've watched some of Welch's videos. One of the best things I've seen is the MIG welding sticky and videos in this forum.

I am interested in putting it back the way it was. I'm just now beginning this restoration journey, and appreciate this resource. When I'm actually ready to tackle this particular job, I'm sure I'll be asking specific questions.

Thanks again,

Kevin

Thanks Bartamos ,that sounds like great trick for patch panels. Appreciate the tip

@WarEagle1
That joint between the floor and kick panel is a vertical lap joint. The floor is flanged down to be paralell with the kick panel. They can be spot welded or plug welded thru that flanged down part of the floor. The floor and flange fits over the rocker panel there as well, so there are 3 layers of steel to weld thru.
Here's a pic from the bottom.

Appreciate it kl. I can visualize it by studying your pic along with attached. I'll have complete understanding of it before I tackle it, but at least I know more now than I did.

Sorry I didn't realize you were working on a 65 truck.
Mine is a '51. Different, but probably similar.

10-4 , when I start actually working metal I'll have a lot of questions that I hope you and Bart. can assist with

I started welding when I was 13 years old which is 71 years ago so have run a few beads. Bartamos' method is as good as I know for curved surfaces. For flat surfaces I like to lay the new on top of the old and cut through BOTH with a thin blade. This gives a very tight fit so no gaps to fill in. With that said we use 3M panel bond for all fire wall patching, roof inserts for soft top cars of the 30's, and any other non stress areas. Enough bond is used at the joint so it squishes out in both directions from a 1 to 1.5 inch lap. This gives a joint that is absolutely waterproof, strong as welding, and done in 1/10 the time.

Butt weld where patch and trans cover were cut together:
[img]https://i.postimg.cc/DJH0X24g/Int-and-57-floor-001.jpg[/img]
If done today it would be BONDED.

Overhead mig weld isn't as pretty on tri-five rear shock mount area:
[img]https://i.postimg.cc/G8CdwHD6/Int-and-57-floor-002.jpg[/img]
This would be WELDED if done today.

The method I gave is mostly for flat. Can be used on curved.

The method of "cut and butt" described in good detail by Bartamos really works well. If you are interested in seeing detailed videos of this method, do a web search for "Fitzee's Fabrications"on Youtube. Tony Fitzee, located in Newfoundland, is a wizard at this method. I have watched all of his videos, and after seeing them, I changed my method of welding patch panels to fit his advice. Since that time, I've welded in many replacement panels, including an entire top cowl, patches in fenders and doors, side cowls, and quarter panels--the results have skyrocketed in both ease and quality compared to my previous work. Take a look at Tony's videos--they are not only edifying, but plenty entertaining--and you will learn a ton about doing metal repair with very few specialized tools.

Yes, that is where I got the method. Been watching his videos for months. His other specialty is making patch panels in pieces rather than forming out of one piece. Much Much easier. More accurate. An important part of that is leave the rusted area on the body. Do not cut it out until the end or near end. A very innovative guy. Amazing results. A said, he uses no special tools. Of course we will have to gain experience thru trial and error like he did, but his videos will help short cut some of that.

He has had to repair some very rusted areas due to lack of non rusted vehicles in his little corner of the world. An island to boot. This is a prime example of "necessity is the mother of invention". Some of the bodies he starts with, I wouldn't even consider buying. It's eye opening as to what can be done with a rust bucket. I urge watching all of his dozen or so videos. As well as Paualo Funileiro, Arthur Tussik.......

Foreign countries, sometimes second and third world, do not "total" ANY cars or trucks. They don't crush them like we do. Increasingly, we only fix "minor" damage by replacement. We do this in the name of "safety", structural integrity, cost effectiveness and insurance company guidance. Other parts of the word buy our totaled cars and ship them over there and fix them like Arthur Tussik does. The American bodymen claim he is doing dangerous work. They don't know what they are talking about. They are brainwashed by the industry. Our collision shops could not do what these guys do. The foreign guys are doing the same thing with the new damaged luxury cars as we are doing with our old trucks when we are rebuilding, restoring, swapping, patching, chopping, re-skinning, clipping, boxing, 4 bar'ing, shortening, lengthening, lifting, dropping, hot rodding, modifying, bagging, customizing............... oh yeah, don't forget those circle/oval/dirt track guys with their secret tricks that were copied by the automakers.

Bartamos A lap joint full of solder wont be able to rust, that harris solder is a good product !!

I am a huge fan of the "Cutt and Butt" method. And I find that it works fine for cab corners, you just have to leave the corner loose until you get there. I highly recommend "Fitzees Fabrications" on YouTube. He does a real nice job on education. I will add a few photos of some of my work with this method.

Steve

In my photo of the inner door bottom, you can see that I left the outer skin in place. This let's me know that the replacement panel is in the right place. I see my captions are ine photo off, but you can figure it out.

Some casual observations after watching the above video... I would not recommend any novice use a 24 or 36 grit sanding disc on a 7" disc grinder for removing welds, as was shown in the video. Too much heat generated, can't see where you're sanding, a recipe for disaster when someone sands half the panel thickness away, or worse yet, sands through. I prefer using cutoff wheels to dress welds for the minimal contact patch (minimal heat buildup) and a virtually unobstructed view of what you are grinding for less chance of panel damage. As shown here:





For the most part his welder is not set up hot enough, or there would not be so much rework after grinding. If you need to reweld after grinding, turn up the heat, you are not getting a full penetration weld. And now you need to grind again.


Part of the reason we use butt welds is to duplicate the original metal "flavor and feel" so that when someone looks inside a door skin or under the floor pans, they don't see a flange repair, or have to contend with ghost lines on exterior painted panels. If we can effectively cut out damaged (rusty) metal, butt weld in a new section, planish/metal finish/filler as needed, we can have an invisible repair that for all practical purposes should be a permanent repair. The patch is normally already shaped to match (in the case of repops) so that the crown of the patch matches the existing panel. (NORMALLY) Part of the reason you see recommendation to use TIGHT butt welds, is that it eliminates open area that allows any panel movement, ie: as the weld shrinks, the panel pulls together. If the crown of our patch used to match prior to welding, weld shrinking along with the panel's pulling closer together (due to the gap) is going to pull in some of the crown. If it is a flatter crown, such as the middle of a quarter panel or top of a roof/hood, it is more noticeable as the crown in these areas is normally minimal/just enough to maintain the shape, and may result in oil canning. If it is a concave crown, such as a reverse where the wheel opening flare comes outward, then the weld seam has a tendency to pull outward as it shrinks. The following pictorial shows an exaggerated crown and gap primarily so you can see it in such a small area. But it shows what happens as weld shrinkage and panel movement pull at the surrounding area. In the bottom view, the red line depicts where the crown was originally.



[IMG]https://hosting.photobucket.com/images/y167/rmccartney/weld%20gaps%20lose%20crown.jpg[/IMG]

With tight butt welds we do need to planish in order to remove any deformation caused by shrinking, and add some stretch back into the area. This should be the extent of our planishing effort, as the tightly fitting panels prevent the panel pull from adjacent areas (that a gap allows, resulting in loss of crown). In the case of any gappage around a patch, we would need to planish even more to add enough stretch to overcome this loss of crown, or add filler as needed.


Looking at the quarter panel in the video, and welding that took place, one would expect in the case of a normal butt weld that the edges of the panels against each other will be a positive stop against any pull from adjacent areas. The only planishing we should need to do is to overcome any shrinking issues due to weld heat. While the theory looks good on paper, the angle cut did indeed close up the gap when compared to a straight cut. But it did not totally eliminate it. My concern with this type cut is that two angled surfaces do not provide the positive "stop" that a truly butted panel does in preventing panel pull from adjacent area. After the grinding process is done, checking the weld seam with a 6" ruler may show how flat that single weld is, but our main concern should be the crown across the entire patch to see if it has pulled inward causing a loss of crown. A defect such as that will be a pain to correct, filler or otherwise. I'm not intimately familiar enough with the method to say this will indeed be a concern. But these thoughts are more cautionary, to give you things to be aware of, to look for.. if you do give this method a try.. For the quarter panel and the upper and lower weld line he used, I would expect any shrinking/panel pull to cause the following issues to the crown:


[IMG]https://hosting.photobucket.com/ima...aps%20lose%20crown%20quarter%20panel.jpg[/IMG]


…..and to a lesser extent, the slight crown from front to back, as the weld shrinks, will pull slightly inward. Armed with this theory on shrinking and panel pull, these are merely things to look out for. More planishing perhaps may be needed to remove any defects that might show up.

While I would agree that using 24 grit discs is aggressive, I am a big fan of Fitzee. I grind my welds with different tools depending on where they are. Sometimes I use a cut off wheel, other times I use my 4 1/2" air sander with 40 grit flap disc or my 2" roloc 60 grit flap disc on an angle grinder. It all depends upon access, what I am grinding and how I plan to finish it. When you do short little stitches, it is not uncommon to have to reweld your start/stop points. Don't get too egar and make long beads as you will not like the warpage that this can cause. If I have access, I will grind the inside. I know that I have good penetration when the inside bead looks like a weld. In the photos I posted, there was very little need for filler after grinding. The cab corners could easily been metal finished, so it does work on curves. Just my experience with this method.

Steve

Without getting into how good of a welder a person is or how big the bead stick up is, I think Robert is saying that the best way for someone not as experienced as Fritzy with the 7" sander should use an angle grinder size hard disc. This enables you to just tangent grind the bead and not touch the adjacent metal. He would do it that way and so do I. If a person wants to try any other method, go for it. The last blending/smoothing can be done with much lower aggressive methods.
Robert is a least as experienced as Fritzy. Fritzy's method works for him but is not what most other experienced persons do. Many times Fritzy mentions that he uses a THICKER patch material than the vehicle metal, so that he does not get it too thin when grinding. Most others use the same thickness patch as the parent. Let's stick with Robert instead of Fritzy on that particular point.