Builds 1977 FJ40 Rebuild – Focus on Custom Stainless Tub (6 Viewers)

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Thanks much knuckle47. We too like the way it looks, four shades of green, rusty front fenders, and all. There is still a lot to go, but the work has slowed since being back on the road. This thread is still not up to current though, so more soon.
 
And now several pics of the cowl - and even through it might look like we used some mud/filler, these different colors are new and old layers of primer and paint. And as before, the black is SEM Rust Trap, and it is compatiable with the primer and top coat.
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And below we jump straight to Rustic Green, but we did spay two coats of primer before this.
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Curious as to your decision as to go with Sem verses POR, Rust Bulletin, or Eastwood products?
 
Since we plan to build additional 40s and an extended cab 45s after this build, and because we will be cutting everything on a plasma CNC table, we made every effort to make this process as repeatable as possible. To do this, we starting making drawings of each of the components and panels that we plan to cut and form. We also designed the panels so they could generally be bent either with a hammer or a home made bender (don't run just yet, these can result in very clean bends), and sometimes both. Later in the build, I did manage to pick up a 13 Ton press for very cheap, but more on that later.

We went through the same process for each panel and continued drawing each part and/or panels, test cut most of them in carbon steel (much cheaper to make a mistake), and refined the drawings if / as needed.

Driver's Floor
Below, you will see various pictures of the driver's floor. I'm starting with this floor pan in that it was one of the first panels that we built and you will see the manual bender that we built and used to bend most of the edges on this floor panel. If you look closely, you will see that some of the hammer rolling is a little rough. You can get much better at this with a little practice and this was cleaned up later. I also have an air chissel that I purchased plastic (I don't recall the durometer rating, but let's say it medium-hard to hard, maybe 80 - 90 Shore A), brass, and steel hammers. And again with a bit of learning and attention, these can be a big help - and even though their heads are slightly rounded, it is not difficult to press hammer head edge marks in the the rolled area if you get your hitting angle wrong, especially on tigher inside corners. I find it best to use the round end of a ball peen hammer for these inside corners.

Below are several pics:
  1. A drawing of the driver's floor with the hammer jig overlay that would allow us to bend the curved edge for the transmission hump area.
  2. I then convert these drawings to DXF drawing files, which are then converted to a G-code files that will be used by the CNC table (see upper left portion of the pic. The G-Code file simplistically contains X, Y, and Z move coordinates and Torch on / off commands that in the end cut the stainless panel.
  3. The main floor panel about to be cut on the CNC table.
  4. The resulting panel about to be bent on the homemade bender.
  5. and onward - Several shots of the resulting floor replacement along with mounts and the small piece that lives just below the gas pedal.

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In the below picture I use several large C-clamps to pinch the stainless in place between the blue channel to the top of the bender. Then you just push / rotate the rebar handle on the left to make the bend. Not the best pic and I can't locate any with the clamps, but you get the point. For what its worth, this little bender is pretty useful, simple and inexpensive to make, especially for as low-tech as it is. You will also need a sturdy and secure table to clamp it to.
View attachment 3752770
The above bender was used to bend all edges on this floor panel other than the edge for the tranny. And I was concerned I would damage it when bending the long rear and outer edges, so I only managed to get a roughly 80 - 85 degree angle on these two edges and I used a large rubber mallet for the last 5 - 10 degrees.
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Were you able to reuse the body mount bolts or did you replace all body mount bolt with OEM or something else? I am looking for replacement bolts/nuts for my rig.
 
Curious as to your decision as to go with Sem verses POR, Rust Bulletin, or Eastwood products?
I don't have a very scientific answer for you, but I have been trying to defeat rust since I was quite young helping my dad on his cars. And by 18, over 40 years ago, I had my first car and continued to fight rust. By the late 80s I was using POR and it was pretty good when it stayed on, but sometimes, it would peal off - in sheets. I should also point out that I was very meticulous about the prep work and used all three of the POR products for prep, clean and coating. After my first pealing experience, I figured it was my fault, and I tried it again on my next job, read all of the instructions again and very carefully cleaned and prepped the surface, etc. And again, it seemed excellent for a while, but then I had the same issues.

Then I talked to a friend who has a body shop and he introduced me to Rust Trap. One of the first differences was that Rust Trap was bottle much better than POR and you can seal it over and over again and still use it, as long as you don't exceed the recommended 1-year shelf life, at least not by too much. I have also used Rust Shield, and it too is quite good, but is not moisture cured. Rust Trap is thin like POR and I generally use a minimum or 3 coats, and generally 4, unless I'm spraying it and use 2 to 3 coats. And it is very flexible - I have separated by brand new leaf packs for my BJ42, painting each leaf with Rust Trap, and I'm hoping that it holds up for a long time.

I have also used the Eastwood products and they are decent, but I didn't have the best experience with Rust Converter, so continued to use Rust Trap and generally then top coat.

For a more scientific view to your question, see the following videos. This fellow does and excellent job of testing, using a diverse set of tests in a repeatable, comparable manner - he too is not a fan of POR - your mileage may vary - I know some love it and I have no intention to bad mouth it, just sharing my experience, which is admittedly a bit old.

It is also worth mentioning that for my 40, I plan to pull the tub and want the frame to look pretty close to new before the tub goes back on. But, if you are just trying to preserve a frame that is in good shape, and don't care if you can eat off of it, either Fluid Film and/or Surface Shield do an amazing job and they take a lot less time to prep and spray, in general. For example, my daily driver is a 4Runner and I simply apply Fluid Film before winter and it worked amazingly well. I'm thinking of using both this coming fall, using Surface Shield in areas that see a lot more water spray from the tires, and Fluid Film on the rest.
  1. If You Think POR 15 is Good Paint... Watch This Video! Paint Testing Eastwood, KBS, POR15, and More.
  2. Best Rust Encapsulating Paint... POR-15, KBS, Eastwood Platinum, Raptor Liner & More.
  3. MOST Rust Converters Are A JOKE! Let Me Show You. (Eastwood, KBS, Corroseal, Ospho & More).
Sorry this is getting long, but I have also transitioned to trying out Mastercoat Permanent Rust Sealer & Chassis Black Finish Combo (AG111). It is thicker than POR and Rust Trap, and only requires 2 + 1 coats, whereas I almost always go with 3 or 4 coats of Rust Trap unless I'm spraying, when 2 to 3 will do. One of the recent jobs I use the Mastercoat combo on is to protect angle iron that serves to tie several pieces of lumber together out at the road - this was intentional to help test it against full weather, sun, and winter salt.

Regarding salt, POR advertises 1000 hours for the salt spray test, although I have seen 2000 hours at this test. SEM doesn't publish their salt spray results to my knowledge and I have talked to SEM engineers, but still no luck. In comparison, Mastercost publishes the following:

"Mastercoat Permanent Rust Sealer is a moisture cured urethane. The more moisture in the air, the faster it dries so it’s actually strengthened by moisture. The aluminum powder in the coating cuts off the oxygen so the coating itself is waterproof and air tight. It’ll withstand 8000 hours of salt spray. This product was originally developed in the mid-70’s as a bridge primer. Bridges coated with 2 coats of silver and one coat of color such as our AG111 Ultimate Finish Coating have a documented 20-25 year service life and will take up to 14,000 hours of salt spray."

Hopefully something above helps you with your choice.
 
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Were you able to reuse the body mount bolts or did you replace all body mount bolt with OEM or something else? I am looking for replacement bolts/nuts for my rig.
I replaced all of the bolts and mounts with the Energy Suspension 8.4104 Body Mount Bushings Kit. I should say most - in the rear, I used M10 stainless bolts with the new Energy pads - the rear sill redesign needed a differently length bolt.
 
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I don't have a real scientific answer for you, but I have been trying to defeat rust since I was quite young helping my dad on his cars. And by 18, over 40 years ago, I had my first car and continued to fight rust. By the late 80s I was using POR and it was pretty good when it stayed on, but sometimes, it would peal off - in sheets. I should also point out that I was very meticulous about the prep work and used all three of the POR products for prep, clean and coating. After my first pealing experience, I figured it was my fault, and I tried it again on my next job, read all of the instructions again and very carefully cleaned and prepped the surface, etc. And again, it seemed excellent for a while, but then I had the same issues.

Then I talked to a friend who has a body shop and he introduced me to Rust Trap. One of the first differences was that Rust Trap was bottle much better than POR and you can seal it over and over again and still use it, as long as you don't exceed the recommended 1-year shelf life, at least not by too much. I have also used Rust Shield, and it too is quite good, but is not moisture cured. Rust Trap is thin like POR and I generally use a minimum or 3 coats, and generally 4, unless I'm spraying it and use 2 to 3 coats. And it is very flexible - I have separated by brand new leaf packs for my BJ42, painting each leaf with Rust Trap, and I'm hoping that it holds up for a long time.

I have also used the Eastwood products and they are decent, but I didn't have the best experience with Rust Converter, so continued to use Rust Trap and generally then top coat.

For a more scientific view to your question, see the following videos. This fellow does and excellent job of testing, using a diverse set of tests in a repeatable, comparable manner - he too is not a fan of POR - your mileage may vary - I know some love it and I have no intention to bad mouth it, just sharing my experience, which is admittedly a bit old.

It is also worth mentioning that for my 40, I plan to pull the tub and want the frame to look pretty close to new before the tub goes back on. But, if you are just trying to preserve a frame that is in good shape, and don't care if you can eat off of it, either Fluid Film and/or Surface Shield do an amazing job and they take a lot less time to prep and spray, in general. For example, my daily driver is a 4Runner and I simply apply Fluid Film before winter and it worked amazingly well. I'm thinking of using both this coming fall, using Surface Shield in areas that see a lot more water spray from the tires, and Fluid Film on the rest.
  1. If You Think POR 15 is Good Paint... Watch This Video! Paint Testing Eastwood, KBS, POR15, and More.
  2. Best Rust Encapsulating Paint... POR-15, KBS, Eastwood Platinum, Raptor Liner & More.
  3. MOST Rust Converters Are A JOKE! Let Me Show You. (Eastwood, KBS, Corroseal, Ospho & More).
Sorry this is getting long, but I have also transitioned to trying out Mastercoat Permanent Rust Sealer & Chassis Black Finish Combo (AG111). It is thicker than POR and Rust Trap, and only requires 2 + 1 coats, whereas I almost always go with 3 or 4 coats of Rust Trap unless I'm spraying, when 2 to 3 will do. One of the recent jobs I use the Mastercoat combo on is to protect angle iron that serves to tie several pieces of lumber together out at the road - this was intentional to help test it against full weather, sun, and winter salt.

Regarding salt, POR advertises 1000 hours for the salt spray test, SEM doesn't publish their salt spray results to my knowledge and I have talked to SEM engineers, but still no luck. In comparison, Mastercost publishes the following:

"Mastercoat Permanent Rust Sealer is a moisture cured urethane. The more moisture in the air, the faster it dries so it’s actually strengthened by moisture. The aluminum powder in the coating cuts off the oxygen so the coating itself is waterproof and air tight. It’ll withstand 8000 hours of salt spray. This product was originally developed in the mid-70’s as a bridge primer. Bridges coated with 2 coats of silver and one coat of color such as our AG111 Ultimate Finish Coating have a documented 20-25 year service life and will take up to 14,000 hours of salt spray."

Hopefully something above helps you make a choice.
Thanks, that is a lot to chew on and very good information. I have never used POR personally. I used Rust bullet on the frame and undercarriage of my 77 Bj and it has held up well for 10 years with still more years available. I may give SEM a try.
 
Thanks, that is a lot to chew on and very good information. I have never used POR personally. I used Rust bullet on the frame and undercarriage of my 77 Bj and it has held up well for 10 years with still more years available. I may give SEM a try.
And since the above is so long, I will emphasize that I'm leaning more toward the Mastercoat Combo - if you can get it - it is almost always sold out and I have heard good things about Rust Bullet as well, but have never used it. I'm pulling the bed off my son's pickup this weekend and will be doing the frame and underside of the bed with the Mastercoat combo - I plan to thin and spray this time.
 
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My own experience with POR was identical to yours @psmbfuer … it peeled off in sheets around 2-3 years after application…. It was for a boat trailer and application was not difficult for reaching all areas properly.
 
My experience as well. Rust converters are a joke. I wish I'd known about Mastercoat years ago. That sounds like its
been properly battle tested with bridges and is making some strong claims. @psmbfuer ... you've practically covered the whole
issue in one post. Well done.
 
Thanks for the inputs @knuckle47 and @wimberosa - reassuring to see similar results. It's a shame that it has taken most of us decades of trial and error, researching, etc., to figure this out. And just when you think you have it sorted, the regulations and chemistry of your favorite paint changes, or something game-changing comes out to change your workflow - which can be a good thing, even if unexpected.
 
My experience with POR is as above. I’m am a fan of Mastercoat… only issues is getting hands on some which depends on when conditions are right for them to make another batch.

Eastwood has been ok - better than POR by far in my experience.
What were your issues with rust converters? Did they peel or did the corrosion just bleed through over time?
 
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What were your issues with rust converters? Did the peel or did the corrosion just bleed through over time?
POR would peel despite proper prep.

I did rust reformer and corrosion would resurface (pun intended) about a year out. The Eastwood rust converter (not the gel) has given me results that last longer. The Gel is POS in my experience.
 
Bleed through!

I had the entire front of my LX450 off to replace the radiator, front main seal, oil pump o-ring, etc., and with this of course had excellent access to the frame. (We took a break from the 77 FJ40 to get the LX freshed up for my son 16th birthday.) The passenger side frame top had surface rust and I figured I would give Eastwood Converter a try - it was a small area and I just wanted a simple spray-can solution. The Converter was new and I prepped the frame well with the needle scaler, sanding, and acetone - and the paint went on well, and had a very consistent and good looking finish, slightly flatter than semi-gloss. It didn't take long, (not very accurate, but I just can't provide a more meaningful timeframe) and the finish gave way to bleed through. That was back in 2017 and the last time I haven't touched EW Converter since.
 
After getting the 40 back on the road, we quickly realized that the rear bumper extension reached out into the wheel opening too far. That is what you get for using 31 inch tires in the drawings, and then upgrading to ~32s. We also still have some serious driver's side rear spring sag that hadn't yet been corrected.

It wasn't a big deal and it only rubbed when hitting a decent bump, but none the less, it needed to be corrected, so we trimmed the rear bumper extension, welded it back together, and we are all good, with no rubbing, regardless of how flexed.

We also needed to cut and insert an extension into the exhaust, bringing it further to the rear before dumping to the outside, as you can also see in the following pic.
Custom FJ40 Stainless Tub On the Road Again-17.jpg
Custom FJ40 Stainless Tub On the Road Again-18.jpg
Custom FJ40 Stainless Tub On the Road Again-19.jpg
Custom FJ40 Stainless Tub On the Road Again-22.jpg
 
@psmbfuer everytime I see your welding photos I want to drag out my welder and melt some metal.. these are such great fabrication talents. Fortunately my flap discs can make up what my fine detail welding can’t.

Here s a quick question…. My Millermatic 211 has .023, .030 and .035. What might you suggest is a happy medium for under 3/16 and then over 1/4 steel? The .023 seems to bunch up in the cabinet and not feed as easily into the hose. Being stiffer, the other go thru easily but, I think I’m am missing out using the .023 for finer gauge
 
Creating the Quarter Panel
For anyone that might not have drawn something like a quarter panel, here is how we approached this. We don't have anything fancy, for example a laser scanner, and we have no formally schooled in this area, nor work related experience in this field, so others might have better advice or techniques, but this is what worked for us.
  1. Take a photo of the quarter panel with the lens face centered and as parallel to the quarter panel as possible. Below you will see that I also did this specifically for both fuel door openings.
  2. Import the photos into my drawing software, use several references points to scale the photos to the correct size, then use the photo to trace the curve in the panel around the tire opening. This outline drawing is just a starting point and the key is to have the curves as accurate as possible. Depending on the lens you used and other circumstances, you might need to account for lens distortion. You will see that I took separate photos of the fuel doors to help minimize any distortion.
  3. Then finish drawing the part, get all of your measurement as exact as possible, and possibly slightly resize the curves that you traced to match real measurement. When you have something like a quarter panel that is long and bent, an easy way to get a length measurement is to use a non-elastic string, tape it to the quarter, in the front for example, place a mark on the string at the exact starting point, wrap the string the length of the quarter, around the rear radius and mark it again. Remove the string and measure it from mark to mark.
Below are several pictures that we used when drawing both an 84 and 77 quarter panel. We also inserted a screen shot from my drawing software showing this hybrid (picture trace / drawing) approach to get the curves of the rocker panel correct - apologies that we can't locate an example at the moment using the quarter panel.
I unfortunately attached too many photos and the next three were automatically removed and I had not noticed. I have not re-instered the next three pics in Post 22.

84 BJ42 Quarter Panel (79 - 84)
  • See pic below in Post 22
84 BJ42 Square Fuel Door (79 - 84)
  • See pic below in Post 22
77 FJ40 Rectangle-Shaped Fuel Door (this pic is from a 78 actually, and not the truck I'm currently working on, but they are the same - this will be a valid door for 75 - 78)
  • See pic below in Post 22
Apologies, but my current drawing revision no longer has the quarter panel picture in my CAD drawing, so I'm using one from the rocker panel drawing to convey this point. Below, I use an actual photo of the rocker used to create clean curves that align to those on the 40. The gray area below the pic is the actual rocker panel that could be exported as a DXF for cutting on the plasma table.
View attachment 3754066
In order to bend the quarter panel lower curved edge, we are going to use a hammer jig. The hammer jig will be 5/16th steel plate that will look very much like a quarter panel, but it will be shorter and roughly 5/8th of an inch short where needed, so we can bend the stainless panel around the hammer jig creating this quarter panel lower lip. Hopefully the following picture helps to communicated how this will work.
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The below pic is not the best and it is somewhat difficult to tell what is going on, but I have created two of the 5/16th hammer jigs, one for a 75 - 78, and one for an 79 - 84. I have also cut an 18 gauge stainless quarter panel. This stainless panel is sandwiched between the to hammer jigs. You can't see the 77 hammer jig in that is is beneath the stainless. You will notice that the square 84 style fuel door on the left side of the panel - this is not used when rolling the edges of the 77. The upper hammer jig is there so you can get clean, small radius bends at the lower jig edge. If you don't have a plate on the top, you are tend to get a more rounded radius. The upper plate also helps to secure everthing in place, even though it is clamped. I then need to remove the upper jig to hammer role the fuel door opening, but I still use thick plates in the area to keep the radius sharp.
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The pic below better shows the fuel door. We use a ball peen hammer for the corners and raise it off the table to get the best angle possible.
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Bending of the sweeping rear radius is a manual process (for us) and is a real handful. You will see in the pic below how we mount it with a piece of wood to our pseudo-welding table so we don't distort anything and then wearing gloves continue to work it into the desired 90 degrees. I also have a jig with the needed quarter panel radius that we use as a reference as we bend this corner. We have also marked the start and stop points of the bend so we have them as references. Also note the square in the pic, it is quite important to mount it square and apply presure evenly so you do twist the panel. And for those paying close attention, you will notice that this is the diver's side panel - we don't have any pics while bending the passenger side.
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And in the end, we needed help to reach a full 90 degrees
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We then reinstalled the filler door neck receiver and because we redesigned the rear sill, we also installed the quarter corner support, which will bolt and be welded to the rear main sill. You might also note that I had to extend the front lip with stainless washers. I need to add about 5/16th to my drawing, so this front lip would not need these.
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Wow. Awesome. Just started reading thru. Having the right tools is key. 😬
 

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