Builds 1977 FJ40 Rebuild – Focus on Custom Stainless Tub (1 Viewer)
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psmbfuer
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- #42
In post #38 above, I mentioned that you will need to remove a piece of lower front quarter panel to slide the mid-tub cross member outer top panel, assuming that you want to keep this panel in one piece. Since my quarters were so rough, and since they were going to be completely replaced, this was an easy decision - your mileage may vary. I also mentioned previously that there are three layers of steel on the rear side of this panel where all of the original panels come together. The pic below give you the best shot that I have of both of the above.
psmbfuer
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- #43
Tinman – A Quick Sidebar
Derailing my own thread to share a little fun, and connecting back to the final pic in Post #34 - this was a door skin for a custom trailer that we built largely for the same reasons as the FJ40, to go camping, primarily out west. I purchased a military trailer and a military EMP/Bio-hazard shelter, then mounted the shelter, built out the inside and outside, and headed west, in what we now called Tinman.
We went out during my son’s spring break, which coincidentally landed us in the middle of “Easter Jeep Safari/Jeep Week”. This was a fantastic week and trip, camped roughly 25 minutes west of Moab, and biking many trails in the area. A week like this makes the work worthwhile.
It could only have been made better if we had a Land Cruiser suitable for pulling Tinman at the time.
Here is Tinman after we strapped the shelter onto the frame to bring it home - about a mile drive.
Here is our camp set up west of Moab.
And a pic back at home, with a few upgrades - the crutch leg for the sliding kitchen worked reasonably well, but this one is much more sturdy.
Derailing my own thread to share a little fun, and connecting back to the final pic in Post #34 - this was a door skin for a custom trailer that we built largely for the same reasons as the FJ40, to go camping, primarily out west. I purchased a military trailer and a military EMP/Bio-hazard shelter, then mounted the shelter, built out the inside and outside, and headed west, in what we now called Tinman.
We went out during my son’s spring break, which coincidentally landed us in the middle of “Easter Jeep Safari/Jeep Week”. This was a fantastic week and trip, camped roughly 25 minutes west of Moab, and biking many trails in the area. A week like this makes the work worthwhile.
It could only have been made better if we had a Land Cruiser suitable for pulling Tinman at the time.
Here is Tinman after we strapped the shelter onto the frame to bring it home - about a mile drive.
Here is our camp set up west of Moab.
And a pic back at home, with a few upgrades - the crutch leg for the sliding kitchen worked reasonably well, but this one is much more sturdy.
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psmbfuer
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- #44
Getting back to the 40 build.
Mid-Tub Cross Member - Driver's Side – Putting it back together
After disassembly, we again cleaned all metal surfaces mechanically and chemically, and then painted most of them with multiple coats SEM Rust Trap.
You may have noticed back on the 4th and 5th pics of post #38, that we might be about to violate our self-imposed rule about not having stainless to carbon lap joints, especially when plug welding them together - and we are, but we will not be using plug welds.
In the case of the center portion of this channel, it was in excellent shape, and while we could have left it fully intact, we decided to remove what you see below, so the floor will have a stainless to stainless lap, while the lower channel has a carbon to stainless lap. We could have gone further and replaced the lower lip with stainless, but it just didn’t seem worth the added time (and at this point, we were still operating under our Moab trip deadline), so we went a slightly different and quicker route.
As you will see in the next pic, we decided to use panel adhesive, nuts/bolt, and butt welds. The nuts/bolts will be below the floor line, so unless you are working under the truck, they will not be visible – they could also be removed, but we don’t plan to do this. I also expect that this lap will last for the rest of my life, and well into my son's, so we decided not to perform the added surgery necessary to replace this lower lip. [Edit]: I also should have made it clear that the above internal channel lap joint surface was cleaned / prepped with a 36-grit grinding wheel before applying the panel adhesive that you see below, so there are no paint drips remaining and the 36 grit provides relatively deep scratches for added mechanical surface to adhere to.
We used SEM Multi-Purpose Panel Adhesive, a two-component epoxy, and the following comments are with the SEM product in mind, although 3M has similar products, with similar prep and installation procedures. And since I have mentioned SEM several times throughout this build thread, I should also state that I have no commercial relationship with SEM, but mention them simply when we used their products in this build. From my experience, they have very good products, and the closest automotive paint store carries a full line of SEM products and no 3M, PPG, etc).
The SEM panel adhesive has a working time of 90 minutes, and cures in 24 hours. You will also need a specific dual tube applicator and mixing tips.
Before application, you need to chemically clean, scuff with 36 grit, and re-clean the surface. Both mating surfaces are treated with a complete coat of the panel adhesive. The SEM panel adhesive contains glass beads that should serve as micro-spacers, so you can’t squeeze too much of it out of the joint, but you shouldn’t apply too much clamping pressure – apologies that I do this by feel and don’t have a empirical number to share.
Here is the patch panel with its mating surface also coated. Note that the left most ~1/4" was left clean. This was done in that the left side would be butt welded and we don't want the panel adhesive in the weld. Also, from memory, you want to complete your welds before the working time expires, as to not diminish the strength of the adhesive.
And the next three showing the final installation.
Started to grind before taking the pic, and don't seem to have a pic with this ground down.
And here are two pics close to the final install of the driver's outer mid-tub cross member.
Below is a shot from the rear side of this panel, showing how it replaces to three original layers, by welding the new panel to the front of the wheel well and the remaining rear channel of the mid-tub cross member.
Mid-Tub Cross Member - Driver's Side – Putting it back together
After disassembly, we again cleaned all metal surfaces mechanically and chemically, and then painted most of them with multiple coats SEM Rust Trap.
You may have noticed back on the 4th and 5th pics of post #38, that we might be about to violate our self-imposed rule about not having stainless to carbon lap joints, especially when plug welding them together - and we are, but we will not be using plug welds.
In the case of the center portion of this channel, it was in excellent shape, and while we could have left it fully intact, we decided to remove what you see below, so the floor will have a stainless to stainless lap, while the lower channel has a carbon to stainless lap. We could have gone further and replaced the lower lip with stainless, but it just didn’t seem worth the added time (and at this point, we were still operating under our Moab trip deadline), so we went a slightly different and quicker route.
As you will see in the next pic, we decided to use panel adhesive, nuts/bolt, and butt welds. The nuts/bolts will be below the floor line, so unless you are working under the truck, they will not be visible – they could also be removed, but we don’t plan to do this. I also expect that this lap will last for the rest of my life, and well into my son's, so we decided not to perform the added surgery necessary to replace this lower lip. [Edit]: I also should have made it clear that the above internal channel lap joint surface was cleaned / prepped with a 36-grit grinding wheel before applying the panel adhesive that you see below, so there are no paint drips remaining and the 36 grit provides relatively deep scratches for added mechanical surface to adhere to.
We used SEM Multi-Purpose Panel Adhesive, a two-component epoxy, and the following comments are with the SEM product in mind, although 3M has similar products, with similar prep and installation procedures. And since I have mentioned SEM several times throughout this build thread, I should also state that I have no commercial relationship with SEM, but mention them simply when we used their products in this build. From my experience, they have very good products, and the closest automotive paint store carries a full line of SEM products and no 3M, PPG, etc).
The SEM panel adhesive has a working time of 90 minutes, and cures in 24 hours. You will also need a specific dual tube applicator and mixing tips.
Before application, you need to chemically clean, scuff with 36 grit, and re-clean the surface. Both mating surfaces are treated with a complete coat of the panel adhesive. The SEM panel adhesive contains glass beads that should serve as micro-spacers, so you can’t squeeze too much of it out of the joint, but you shouldn’t apply too much clamping pressure – apologies that I do this by feel and don’t have a empirical number to share.
Here is the patch panel with its mating surface also coated. Note that the left most ~1/4" was left clean. This was done in that the left side would be butt welded and we don't want the panel adhesive in the weld. Also, from memory, you want to complete your welds before the working time expires, as to not diminish the strength of the adhesive.
And the next three showing the final installation.
Started to grind before taking the pic, and don't seem to have a pic with this ground down.
And here are two pics close to the final install of the driver's outer mid-tub cross member.
Below is a shot from the rear side of this panel, showing how it replaces to three original layers, by welding the new panel to the front of the wheel well and the remaining rear channel of the mid-tub cross member.
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psmbfuer
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- #45
What tools / equipment are really needed.
Based on a comment from my family, there's concerned that younger readers or those just starting out with fabrication might be discouraged from taking on a larger job like a tub build because you don't have, for example, a CNC table, or possibly a TIG welder - and this would be counter to one of the primary reasons for writing this thread.
The reason I mentioned the DXF and G-Code back in Post #14 (and I meant to complete that throught there) is that these formats are widely recognized across the cutting industry. Prior to owning a CNC table (which I picked up at a good discount second-hand - so you might not need as much cash as you think), I would create drawings, in Corel, export them as DXF, using a plugin, and email them to the local(ish) laser cutter. And even now, if I have a smaller drawing that I need to be very refined/accurate, or need to make dozens of the same part, I will send the file to the laser/water jet cutter.
And while the TIG was especially handy when welding my aluminum BJ42 snorkel and intercooler, we use it much less than the MIG. And for this thread, although the TIG was used some, we could have gotten by entirely with the MIG.
And of course you can skip most of the above, and purchase all of the panels and go to town with a few hand tools and a used welder.
The point is, while you need a few core tools, you don't need the expensive, large ones to start - be creative, beg, borrow, but don't steel, seek advice, and enjoy creating - now back to the build.
Based on a comment from my family, there's concerned that younger readers or those just starting out with fabrication might be discouraged from taking on a larger job like a tub build because you don't have, for example, a CNC table, or possibly a TIG welder - and this would be counter to one of the primary reasons for writing this thread.
The reason I mentioned the DXF and G-Code back in Post #14 (and I meant to complete that throught there) is that these formats are widely recognized across the cutting industry. Prior to owning a CNC table (which I picked up at a good discount second-hand - so you might not need as much cash as you think), I would create drawings, in Corel, export them as DXF, using a plugin, and email them to the local(ish) laser cutter. And even now, if I have a smaller drawing that I need to be very refined/accurate, or need to make dozens of the same part, I will send the file to the laser/water jet cutter.
And while the TIG was especially handy when welding my aluminum BJ42 snorkel and intercooler, we use it much less than the MIG. And for this thread, although the TIG was used some, we could have gotten by entirely with the MIG.
And of course you can skip most of the above, and purchase all of the panels and go to town with a few hand tools and a used welder.
The point is, while you need a few core tools, you don't need the expensive, large ones to start - be creative, beg, borrow, but don't steel, seek advice, and enjoy creating - now back to the build.
psmbfuer
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- #46
Before progressing further toward the rear of the tub, we are going to need the passenger ambulance door repaired so we can use it for fitment as we replace the wheel wells and the rear sill. The door, as with much of the body is in pretty rough shape and will need a full outer panel across the bottom and other patches.
Here is the door before starting to cut out the old rust.
Here is a shot after cutting the primary areas of rust out.
Here are the primary patches and the original nut plates that have been removed and painted for reuse.
Inside of the lower, outer panel and the lower hinge mount area. We wrapped both, so that the portion that wraps around the door should look original, but in stainless.
Here is a shot of the hinge patch final fit, prior to welding. We still need to reinstall the nut plate as well.
Here is the door before starting to cut out the old rust.
Here is a shot after cutting the primary areas of rust out.
Here are the primary patches and the original nut plates that have been removed and painted for reuse.
Inside of the lower, outer panel and the lower hinge mount area. We wrapped both, so that the portion that wraps around the door should look original, but in stainless.
Here is a shot of the hinge patch final fit, prior to welding. We still need to reinstall the nut plate as well.
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fyton2v
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"Well, I guess I'll just fab my own tub then."
Amazing work.
Amazing work.
Jim S.
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Really nice work. In the 2nd to last photo of the door panel you show the welds before blending, I would like to know what you used to blend the welds in the compound curves. I may be old, but I'm still new at this metal working.
Thanks
Thanks
psmbfuer
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- #50
Thanks very much fyton2v and Jim S. We have really enjoyed the though process and the work, which makes for better results. At times, we pushed a little to hard to get it back on the road and we are learning that setting dates, even for good road trip reasons, is not the best approach for us. It adds pressure, results in mistakes or mild shortcuts, and life can throw too many curves at us, so we are getting better at just accepting that it will be done when it is done.
Jim S., regarding your question, below I provide a shot of most of the tools that we would use to grind and finish a weld, and of course many of the tools can take different sizes and types of discs. When finishing the compound curve, we likely started with the 90 degree die grinder, 5th from the right on the air tool hanger below (apologies this is the only decent pic of the grinders that I could find and I'll get out to the shop and get you a better pic tomorrow). We may have used various grit flapper discs or even just a flat grinding disc to start, we keep a supply of 1, 2, and 3", of various grit. We then likely moved to a 2" used 180 grit flapper, and after getting it close, we likely moved to the DA (dual action / orbital) sander, possibly starting with 80 grit and ending at a worn out 180 disc or 220 - hopefully that helps.
Jim S., regarding your question, below I provide a shot of most of the tools that we would use to grind and finish a weld, and of course many of the tools can take different sizes and types of discs. When finishing the compound curve, we likely started with the 90 degree die grinder, 5th from the right on the air tool hanger below (apologies this is the only decent pic of the grinders that I could find and I'll get out to the shop and get you a better pic tomorrow). We may have used various grit flapper discs or even just a flat grinding disc to start, we keep a supply of 1, 2, and 3", of various grit. We then likely moved to a 2" used 180 grit flapper, and after getting it close, we likely moved to the DA (dual action / orbital) sander, possibly starting with 80 grit and ending at a worn out 180 disc or 220 - hopefully that helps.
Jim S.
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Thank you sir. I appreciate your detailed response. This site is great for sharing tips and information.
Jim
Jim
psmbfuer
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- #52
Sure thing Jim S. and since you are curious about this door hinge patch, I located several additional pics of the area and of the patch panel that better show how the piece was made and where the grinds actually where.
The first pic below shows all three pieces, including the paper template of the base shape, also used to locate / place the screw holes on the new patch. We almost always start with a drawing of the patch or in this case, no drawing was made, just the paper template. We then build the new patch before removing the steel from the impacted area, then use the new patch, and to a lesser extent the paper template, to trace out the cut lines.
The second pic shows the area cut clean for the new patch, but with the nut plate still installed. The remaining nut plate spot welds are just below the current opening and can be seen removed in pics in the previous post.
The third pic shows the baseline patch.
The fourth pic is a shot showing a triangular piece being welded in to fill the opening in the patch.
If you look closely below, you can see the locating marks for the nut / screw holes.
The first pic below shows all three pieces, including the paper template of the base shape, also used to locate / place the screw holes on the new patch. We almost always start with a drawing of the patch or in this case, no drawing was made, just the paper template. We then build the new patch before removing the steel from the impacted area, then use the new patch, and to a lesser extent the paper template, to trace out the cut lines.
The second pic shows the area cut clean for the new patch, but with the nut plate still installed. The remaining nut plate spot welds are just below the current opening and can be seen removed in pics in the previous post.
The third pic shows the baseline patch.
The fourth pic is a shot showing a triangular piece being welded in to fill the opening in the patch.
If you look closely below, you can see the locating marks for the nut / screw holes.
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What welding wire are you using?
I am blown away by the fitment and attention to detail.
I am blown away by the fitment and attention to detail.
Jim S.
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Once again thanks. I'm really enjoying this.
psmbfuer
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- #55
Thanks clrussell, very much appreciated - stay tuned and we'll get to some rough stuff as well.
Regarding the MIG wire, we used .030, 309SLI, and tri-mix gas almost entirely for this job. If you drop back to Post #11, there is a section that I called "Our Plan to Achieve These Goals", and we go over this and other planning details there - I know it was a long boring text section and I often skip over them as well - looking for pics
.
Here is a shot with of all the info directly from the spool. (Don't let the pic mess with your head, the spool had the label at 6 o'clock when I opened the case today, so I took the pic and rotated it 180.)
Regarding the MIG wire, we used .030, 309SLI, and tri-mix gas almost entirely for this job. If you drop back to Post #11, there is a section that I called "Our Plan to Achieve These Goals", and we go over this and other planning details there - I know it was a long boring text section and I often skip over them as well - looking for pics
. Here is a shot with of all the info directly from the spool. (Don't let the pic mess with your head, the spool had the label at 6 o'clock when I opened the case today, so I took the pic and rotated it 180.)
I enjoy these posts and how you’ve fabricated these parts. How do you address smoothing lines between the new and old metals. I had tried this when I was building BBQ smoker cabinets and seamed to pieces of 16 gauge together. After the 3rd attempt, it was still a bit obvious even after grinding and a few flap discs. Is it feathering a bondo skim coat that does it?
I hope I’m describing this properly. There are some viewing angles that just make it pop out and look only so-so
I hope I’m describing this properly. There are some viewing angles that just make it pop out and look only so-so
psmbfuer
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- #58
Thanks knuckle47. Regarding smoothing the finish weld, if we don't get the panel alignment and gaps just right, and then get the weld just right, without too much heat, it will be virtually impossible to finish the weld so it disappears. You will see as we progress putting all of this back together, that we managed to hit the sweet spot sometimes, but more than not you can will be able to see where the weld was. And we have not used any body filler on the body or any of the panels and may not - there is a change we don't paint the stainless, but time will tell. If we were to paint it, we will need filler in many locations.
Others may have more experience and details to add, but here are additional details that we use to get as clean a finished weld as possible - and most of it is prepping, not finishing.
Others may have more experience and details to add, but here are additional details that we use to get as clean a finished weld as possible - and most of it is prepping, not finishing.
- Obviously, the fabrication fit and alignment are critical, and once we are happy with x and y fitment, it is just as important to align the z axis / depth of the old and new panels. This can be difficult on long panels, but is very important to making the finished weld disappear.
- On butt welds, I like to have a small gap between the original steel and the new panel. Be caution with this on sheet metal in that it increases the chance of burn-through, and the gap are never perfect, but I try to have a gap of roughly half of the metal thickness. To me this allows the best penetration with the least heat, and results in less material to remove from the weld face, which results in less heat getting into the panel during welding and grinding, and greatly improves your chance of a clean finish. Too much heat will tend to distort the panel and also can cause a generally concave pucker at the weld making it virtually impossible to hide the weld without filler.
- If you look back at the first pic in Post #26, you will see lines on the new rocker and mating surface (see below as well). These lines indicated where we needed to remove more metal and we just kept working both sides until we had a clean fit for the length of the panel.
- We tried to build panels / patches so the butt interfaces were along an edge / strong seam or bend, not in the middle of a panel. This too helps to reduce distortions and allows for better smoothing and hiding of the weld.
- To further avoid driving excess heat into the panel, we apply weld nuggets as a series of single, slightly overlapped, tack welds, and we only apply several in the same location (generally 5 or so), before moving to a new areas on the panel. We also used aluminum or copper cooling / dissipation plates, and also used an air nozzle to cool the aluminum heat sink, but not the weld. We use the air sparingly and after the weld has cooled to some extent. When welding the rocker, the aluminum plate never got to a temp that was uncomfortable to touch.
- My shop is generally not heated, so in the winter, the shop and all of the materials in it, including the metal that we are about to weld could be quite cold. And even if we turn on the heater, it will take a long time to heat the air and then everything in it. With this, we often preheat the metal - to me we get much nicer start welds and I believe less distortion when we do this, with less spatter and better penetration. We just use a small butane hand torch and sorry that I can't share exact temps, but we just bring the panel and surrounding area up to a warm to touch temp and start welding.
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psmbfuer
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- #59
I'm only allowed 10 images / post, so now adding the final pics to the above series - you will see that on the rear upper portion of the passenger rocker, the weld is still visible.
And here is a pic with the flash of the driver's side that provides a very detailed view of the surface.
And a similar pic of the front of the driver's rocker.
And here is a pic with the flash of the driver's side that provides a very detailed view of the surface.
And a similar pic of the front of the driver's rocker.
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Wow, thank you for the the detailed explanation. I have air to cool but never used it on my welds as most were just straight and structural. Very few cosmetics. Clearly the results are significant. The next time I’m doing any welding I am making it a point to try this. My 40 is in really good condition but there will come a day when having this under my belt will be a big asset.
