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252 Posts
Discussion Starter #61
Things are rolling - Finishing Wheel Well and Floor Mods

Things really fell like they are starting to roll along nicely. It took me so long to figure out the alignment of the A and B pillars, the roof cross braces, the quarters, and so on; so it feels nice that starting to progress along faster.

Here's the result of the widening of the passenger side wheel well, just like the other side:
20190803_123059 by 7T02S, on Flickr

Now it was time to take the back of the car back apart and get the floor into the car. This was a nice realization because I used to fit the floor in through the door opening but that was difficult and required the door to come off. I'm not removing the doors until I weld in the quarter panels since they are perfectly aligned at the moment.
20190807_185744 by 7T02S, on Flickr

20190804_173342 by 7T02S, on Flickr

You can see that I already drilled all the plug weld holes. I'm pretty sure I did that 1.5 years ago! It's nice to see it back in the car!

Now it's time to modify the back "ears" of the floor that mate up to the wider wheel wells. I made some templates from a shoe box.
20190805_115708 by 7T02S, on Flickr

I did my best to transfer the radius with this curvature gage. It was too long to get all the way done into the lower section, so it just got me close.

20190805_130344 by 7T02S, on Flickr

Here's the transferred cut line.
20190805_123955 by 7T02S, on Flickr

Here are my marks and initial cuts. I am keeping the both sides of the flange but going to have to fab up a flange for the middle of the curve. I don't have a picture but I flattened out both sides and then bent the flange down 90 degrees to match my contour line.

20190805_142435 by 7T02S, on Flickr

Here is a shot with the floor cut on both sides. I got the cut pretty close, so that made me happy. I'm probably going to make a 90 degree flange on the sheet metal brake then shrink/stretch it to fit the curve. That can then be welded into the floor to replace the missing flange to the wheel well.
20190805_143933 by 7T02S, on Flickr


252 Posts
Discussion Starter #62 (Edited)
Weld B-Pillars

I also did my final welding of the B-Pillars to the Rocker Panels. I still have to grind down all the welds. I did plug and stitch welding.

Driver's Side
20190804_154055 by 7T02S, on Flickr

20190804_154111 by 7T02S, on Flickr

Here I added a few stitch welds and did some initial rough grinding of the welds with a 60 grit flap wheel. Note the black primer. This is SPI epoxy primer. I've read many people suggest brushing or rolling this onto flanges before welding instead of weld through primer. Seems to work quite well.
20190804_173637 by 7T02S, on Flickr

Passenger side. You can see a four spot welds I added that above the rocker line.I would have thought dynacorn would have welded down a little further than they did. You won't see epoxy primer in the joints on this side because I didn't take the pillar back apart before welding - that's because I finally got everything perfectly aligned and decided it wasn't worth taking it all back apart since I was more concerned about losing my perfect alignment with the door, window, wing window, and such. Once I get the car back on a rotisserie, I'll try and pour some primer into the joints.
20190804_173609 by 7T02S, on Flickr

20190804_173602 by 7T02S, on Flickr

I also welded the three plug welds per side shown in the middle of this photo on the B-pillar just above the door line. Dynacorn also didn't weld this joint. Maybe they couldn't reach the spot welder tongs into this spot and left holes to allow easy plug welding? Who knows but they are welded now.
20190807_185601_close by 7T02S, on Flickr

252 Posts
Discussion Starter #63
Removing Original Firewall and In With the New

I started thinking about the sequence of welding in all these panels. I decided that since I'm not going to remove the doors until I weld in the quarter panels to match, this will be my sequence:
1. Brace passenger A-Pillar and front of rocker.
2. Remove original firewall.
3. Brace drivers side A-Pillar and front of rocker while removing driver side torque box
4. Test fit new firewall.
5. Prep flanges of inner fender wells to firewall. Along with this will be epoxy primering all the flanges of all the parts listed below.

6. Weld in firewall.
7. Weld in floor.
8. Weld in wheel wells.
9. Weld in quarter panels, trunk divider, trunk floor, trunk rear brace, tail light panel, roof.
10. Replace front frame rails.
11. Repair front inner fender wells.
12. Replace core support.
13. Epoxy prime the uni-body.
14. Have more beer!

So, here's the start of that list.

1. Brace passenger A-Pillar and front of rocker. What's not shown here is removing the scissor jack that was previously supporting the rocker. It didn't provide much support since I had previously tied down the front frame rails down to my chassis jig. Before, the firewall was supporting the rocker all by itself really, didn't really need the jack but I need to be extra sure of the alignment of the rocker, both in height and rotation for installing the new firewall to the exact same spot.

20190805_162457 by 7T02S, on Flickr

2. Remove original firewall. Lots of spot welds to drill. Most were easy to get to though.
20190805_173222 by 7T02S, on Flickr

Look at all that rust in the flanges! It would appear, again, that the electrolysis dipping process I paid for didn't get everything... Although they did tell me they really had no way of know if they got everything.
20190805_175336 by 7T02S, on Flickr

3. Brace drivers side A-Pillar and front of rocker while removing driver side torque box.

Here I got to break out the plasma cutter. I first made enough cuts to install the square tubing bracing without reducing the integrity of the torque box supporting the rocker panel location.

20190806_181932 by 7T02S, on Flickr

More plasma cutting!
20190806_183636 by 7T02S, on Flickr

Don't forget to wear proper safety gear when plasma cutting. I had no idea I stepped on this hot wedge of steel and it melted directly into the sole of my boot!
20190806_184232 by 7T02S, on Flickr

Here's a clear view of the rocker bracing I added and the front end sitting all by its lonesome self - if you look closely, you can see the four spots I used to locate the frame rails. Eventually I'll be replacing those frame rails too and they should align nicely.
20190807_183602 by 7T02S, on Flickr

4. Test fit new firewall.

I had to unbolt the export brace to allow the cowl assembly to rotate up enough to let the upper firewall flange slide in place. Note I double vise-gripped the upper-rear corners of the cowl to B-pillers - this was to make extra sure that the cross dimension would stay put while I did this. I also fit the floor in and tested the match for the first time in the car. I have to say I'm very pleased with the fit. It's basically ready for welding the firewall and floor in one I prep the flanged and drill plug weld holes in the firewall and front floor edge.

20190807_190338 by 7T02S, on Flickr

I decided to test fit the new seat risers. The firewall is Taiwanese, the risers Canadian, and the one-piece floor is an American stamping - in case you were wondering. ;-)

20190807_190324 by 7T02S, on Flickr

I couldn't help myself and decided to clamp in the entire back of the car - and the roof. YEAH!!! It's moments like this that I really enjoy. I can see the end is in sight!
20190807_192344 by 7T02S, on Flickr

Looking like a car again! Here you'll see the original fenders and cowl.

20190807_192827 by 7T02S, on Flickr

Time to get flange prepping and welding. My goal is to have the entire unibody welded together by the end of August 2019. I think it's an achievable goal. Wish me luck!!!

252 Posts
Discussion Starter #66
Stitch Welding Frame

I decided to stitch weld the rocker panels and rear torque boxes. I had contemplated adding in the convertible inner rockers and components instead of subframe connectors but decided to just go the subframe route. I ordered a set of SpinTech sheet metal subframe connectors - they should be here this Friday!

To add to the structural stiffness, the stitch welding seemed necessary. I'm also going to add in a custom made gusset from the b-pillar to the rear torque boxes based on a brace that's present on the convertible. I'll add a story about that when I get to it.

Anyways, the stitch welding was also necessary before I epoxy prime all the flanges before plug welding.

Here's the passenger side after I completely welded it up. I tried to place the stitch welds staggered with the factory spot welds.

20190817_191148 by 7T02S, on Flickr

Close up where the torque box meets the rear frame rail and the leaf spring mount.
20190817_152254 by 7T02S, on Flickr

Underneath, I add some healthy welds to the leaf spring mount.

20190817_191210 by 7T02S, on Flickr

Driver's side.
20190817_152143 by 7T02S, on Flickr

Both sides.
20190817_191200 by 7T02S, on Flickr

Each side took about 2 hours of welding and 1 hour of finish sanding, for a total of 6 hours of labor.

252 Posts
Discussion Starter #67
If there's one thing I've learned on this project, goals relating to the calendar are hard to meet because you never know what puzzle is around the corner. This time around, I didn't realize how long it would take me to replace the front end. Once I removed the firewall, it left the front frame rails and shock towers jigged up all by themselves. I figured this would be pretty straight forward to repair the shock towers and replace the frame rails. I'll go into this later but I just couldn't get the new Taiwanese frame rails to align with everything. It drove me nuts for months. Finally figured out in the last few weeks that the RH one was manufactured with a bow in it in two directions! That really threw everything off. I finally found a fix (used a press).

Anyways, here's a progression of photos leading me up to the present.

Here I added some supports to the front of the frame rails to help locate the new ones:
20190830_150915 by 7T02S, on Flickr

Here's the removal of the RH frame rail done with the plasma cutter:
20190830_160411 by 7T02S, on Flickr

Here's a closeup of the lower portion of the RH shock tower that I'll need to address. Isn't rust a pest?! What's annoying is that I paid some serious money to have the car dipped and to have the rust killed with the elecrolosis process. As I've taking things apart on this car, it clearly didn't work well enough.
20190830_160420 by 7T02S, on Flickr

The logical next step was to test fit new parts even though it was a long ways from being actually welded in:
20190831_110354 by 7T02S, on Flickr

For the LH frame rail, I decided to drill the spot welds instead of plasma cutting them out. This ended up in a much nicer result:
20190907_131959 by 7T02S, on Flickr

Test fit of both frame rails:
20190907_153959 by 7T02S, on Flickr

At this point, I decided to weld the frame rail extensions onto the frame rails on the bench, instead of on the car. For better or worse, this was the path I chose because I knew it would result in better welds because I could position the parts as I wanted them. In the car, it's all about ackward positions and upside down welding.
20190930_144109 by 7T02S, on Flickr

20191001_182900 by 7T02S, on Flickr

20191003_185808 by 7T02S, on Flickr

252 Posts
Discussion Starter #69
Since I straightened up the RH front rail, everything magically aligned!

I spent a long time trying to figure out the best position of the front frame rails, using the service manual and Liskey drawings and CAD. I might post my CAD results at some point because I spent some time putting both drawings into one CAD drawing so that they would have the same datum plane. In order to do this, it needed lots of measurements off the physical parts, since the FSM drawings use hole locations and the Liskey drawing uses edge of part dimensions to the frame rails. Long story short, I decided to ignore all of that and use the measurements and locations I took off my car before removing the frame rails. This wasn't as easy as it sounds because the two stock frame rails weren't exactly positioned the same at the factory - so which one was correct? I chose to reference the LH rail since it was the one with the torque box.

In order to feel good about the alignment of the frame rails, I realized and discovered the following:
  1. Install all the sheetmetal, fenders, hood, cowl, firewall, floorpan - to make sure that these all line up and the gaps are good. The height of the frame rails is mainly dictated by the intersection of the firewall-to-floor pan and the height of the radiator core support. Those basically set the alignment of the fenders. If the fender is too high or too low, the gap to the door won't be even.
    1. 20191216_151550 by 7T02S, on Flickr
  2. Install the cowl, firewall, and export brace with 1/2" bolts. This aligns everything nicely, including the location of the shock towers.
  3. The 19.13" dimension between the LCA mounts is right.
  4. My final dimension between the frame rails was 701mm.
    1. Get yourself some metric tape measures. Metric rules!
  5. Use a digital level to get the frame rails vertical.
    1. 20191216_154438 by 7T02S, on Flickr
  6. Use an auto leveling laser to get things centered.
  7. Use all-thread to fine tune placement and to keep things where you want them.
    1. Notice in the pictures I welded two square tubes to the frame rails and used all thread to adjust and hold the dimensions. I also used all-thread in the shock tower holes.
  8. The cross dimension between the frame rail extension holes (center to center) came out to be around 29-13/16" to 28-7/8". Which is pretty close the service manual dimension of 29.88.
  9. But LOTS of clamps and vise grips. The HF C-clamps are actually really good, especially the 1" and 1.5" versions. The Bremen brand of HF welding vise grips are superb. I'm a tool snob and appreciate good tool and those vise grips can't be beat, especially for the price.
  10. Check and re-check your measurements a LOT before welding.
  11. Tack weld just enough in place to minimize defelections and securely brace/clamp all components while doing so.
  12. I haven't got to this point yet, but, before fully welding up all of your parts, securely tack in as many components to the unibody as possible to have the structure of the car help keep things from moving when doing all your final welding. This also ensures everything is going to fit. No need to spend months measuring if the welding process shifts everything, right?
Here's where I am as of today:

Frame rails, outer torque box pieces, shock towers tack welded together to the rockers.
20191217_185738 by 7T02S, on Flickr

20191216_165227 by 7T02S, on Flickr

20191218_182640 by 7T02S, on Flickr

Today, my plan is to stitch weld the inside of the torque boxes before placing the top panels on. Welding the top panels on. Then I'll start prepping the firewall to weld in place. That'll include plug welding holes and weld through primer (that's the coppery looking coating in the photos).


252 Posts
Discussion Starter #71 (Edited)
So I made some good progress yesterday. I got the upper panel of the torque boxes welded in place.

Here it is after plug welding. Note I haven't welded the two outside tabs together. This allows me to adjust the height to match the floor and firewall.
20191220_134540 by 7T02S, on Flickr

Because the firewall will rest on these panels, the welds needed to be sanded down flush.
20191220_171552 by 7T02S, on Flickr

Today my plan is to fit in the firewall and hopefully get it welded in place. I think I'll use my spot welder to weld in along the sides of the firewall, so that should save some time there. The two tricky parts are alignment and clamping. Oh, and don't forget prep - I'll have to plan where all the welds will go and remove the black paint and apply weld thru primer. For alignment, it has to align so it's flush with the cowl, kick panels, torque box tops, and the floor pan. For clamping, I have to figure out a way to clamp it down to the torque boxes. That's difficult because there's nothing parallel on the backside of the 45 degree torque box tops. I think I'll use some push clamps and push against a bar I place on the inside of the car.

252 Posts
Discussion Starter #72
Finally got the firewall welded in!!! To see the front frame rails, torque boxes and firewall WELDED in makes me feel like I'm really making progress after months of trying to get things aligned.

On Saturday, it was all about alignment, mainly to make sure the cowl was in the right spot. To do that, I needed to attach the fenders and drop the hood into position. I also needed to level the hood with leveling bolts in the front and wood shims in the back. The alignment of the cowl is crucial because the hood will align to it and they should both center up at the ridge on the centerline and also have an even gap. The cowl also needs to match up to the top of the fenders and be at the same angle. The gap to the fenders also needs to be good. If the cowl goes off center, all the sheet metal, including the doors would have to follow. That's why I pretty much spend all day Saturday dialing in the sheet metal.

Gaps are looking great!
20191221_122802 by 7T02S, on Flickr

Here you can see the green lasers. This allowed me to easily center up the hood and fenders.
20191221_121346 by 7T02S, on Flickr

Final shot before taking the firewall out to prep for welding. I didn't get a picture of it but I have a second auto leveling laser that I move around (the green one is fixed on the ceiling). I made a reference mark on the left shock tower and then sharpie marks across the front of the firewall. This allows me to take it out, prep it, and put it back in place without second guessing the location. A huge time saver and gives lots of peace of mind!
20191221_110609 by 7T02S, on Flickr

252 Posts
Discussion Starter #73 (Edited)
On Sunday, it was all about prepping and welding.

For prepping, I do the following:
  • Remove paint with 80 grit on a DA sander (HF electric works really well) or 120 grit on a pneumatic angle grinder (2" screw on disc). This is on the mating surfaces of the parts.
  • Plug welding hole locations marked per the factory weld and sealant manual.
  • Plug welding pilot drill (1/8") all holes.
  • Unibit to quickly open the holes out to the final size. Once again, the HF unibits work great.
  • 120 grit angle sander to debur the backside of the holes and remove paint from the top side.
  • Blow off.
  • Wipe down with solvent based Wax and Grease remover (not water born).
  • Wipe down with a tack cloth to remove dust and lint from the cloth used above.
  • Spray weld through primer. Light coat then a second heavier coat. Spot in a third coat in areas with light coverage.
    • I'm using a weld through primer called Cobre. It's about $40 a spray can but I did some weld and corrosion tests with several primers and Cobre worked very well. It seems to be very good at corrosion resistance but it also welds as if it's bare, clean metal.
Here's the firewall ready to drop in for the last time. I didn't take a picture but I also prepped and coated the top of the torque boxes with the primer.
20191222_153454 by 7T02S, on Flickr

Once the firewall was clamped into place and level (found a picture with the laser), I spot welded in both sides. You can also see the long vise grip that helped clamp in all the hard to reach spots.
2019-12-23_06-41-38 by 7T02S, on Flickr

To add in a third hand of help in the center of the torque box area, I used this ratcheting cargo bar. This helped push the firewall into the torque box to close up the gaps before welding where I couldn't use any other clamp.
20191222_171732 by 7T02S, on Flickr

Here it is in it's final resting place, some 60 plug welds later!
20191222_184700 by 7T02S, on Flickr

I'm really happy with how the welds turned out. My Miller Autoset 140 welder was one of my best tool purchases for this project. I set it up with an Argon/CO2 mix, 0.030 70S wire, and a heat setting based on the firewall thickness.
20191222_181815 by 7T02S, on Flickr

252 Posts
Discussion Starter #76
More progress has been made. Yesterday was mostly a planning and checking fit and measurement day. After welding in the firewall, I needed to recheck the fit of the cowl, export brace, and shock towers. Everything was still good and in check.

As part of my alignment checks yesterday, I ended going back to my forward rocker panel/torque box supports and let the rocker mount behind it float above the jig and also let the front of the frame rails and LCA bolts loose too. At this point, the way I have the car welded together, the stiffest point is at the front of the torque boxes and firewall. I makes sense to support the weight of the front end there. I had to support the rockers about a foot back on the car when I removed the frame rails and torque box. Now that the torque boxes are installed, I was able to go back to these. Then I just lightly placed some wedge shims under the front of the frame rails to do a minor level adjustement, then tightened down the export brace since it's what controls the torsion. Since I don't have the cowl or the rear fender aprons welded in, the front end can be twisted a bit. Before welding in anything else, I wanted to make sure I was all squared up again. That seemed like the best course of action. It worked as everything leveled out and returned to my center laser line.

Here are the scissor jacks that hold the torque box area I mentioned above and allow for easy leveling:
20191223_222005 by 7T02S, on Flickr

I also decided to do a little dirty labor at the end of the day to sand down the firewall plug welds:
20191223_221950 by 7T02S, on Flickr

252 Posts
Discussion Starter #77
I also got a good amount of things done today (x-mas eve). I spent the morning thinking and planning. I also spent a little time adjusting my spot welder. I wanted to make sure it was producing solid welds before using it for welding in the upper part of the rear fender aprons. I also would really like to use it to weld all three layers together at the cowl. I researched weld strength and it basically comes down to performing a sample spot weld and then doing a peel test. If the weld nugget is ripped out of one of the layers, then you have a good weld.

Here's a picture of a three layer spot weld with equivalent thickness to the three layers at the cowl. With the center layer in the vise, I was trying my hardest to peel the layers apart with a vise grip clamped on the part I was trying to peel. If you look closely, I was starting to pull the weld nugget out of the upper piece. The section I was clamped on actually gave up first. You can see the vise grip marks on the upper piece where I ripped the metal apart while leaving the spot weld intact but still ripping the weld nugget out of it, so that told me it was a good weld. I think I used a 4 or 5 second on time on my welder while keeping decent pressure on it during and after the weld.
20191224_140110 by 7T02S, on Flickr

At around 2pm, I was feeling a bit tired and almost called it quits for the day. I decided to try and push through it by focusing on something small and achievable. Ever heard of SMART goals? ;) I decided to try and get the rear fender aprons prepped for welding in. For this I needed to:
  1. Check final fit with fenders installed since they need to be aligned to the fender.
  2. Check fit against the firewall. I had to bend both flanges at the firewall interface around just a little to make them fit flush.
  3. Drill all the plug weld holes.
  4. Sand, remove all the black paint, de-grease, tack cloth, weld-thru primer prime.
In order to get in to the upper part of the frame rails to sand, I had to remove the square tubes I welded to the frame rails (used all-thread though these tubes to keep everything square). I also had to final weld the rear part of the shock towers to the frame rail. Once I got all of that done, it was time for step 4 above.

20191224_180733 by 7T02S, on Flickr

20191224_180802 by 7T02S, on Flickr

20191224_180814 by 7T02S, on Flickr


252 Posts
Discussion Starter #80
Made some more good progress yesterday. I'm really liking how much I get done on vacation!

1. I was able to get the rear inner fender aprons welded in place.

Since I already primed the interfaces and did some tweaking of the flanges against the firewall, this step wasn't too difficult but did end up having to move the flanges some more after forcing them into the correct positions, more so on the driver's side. Note I installed the fenders into the correct positions. This gave me the angle the top surface needed to match.

I installed a 3/8 threaded rod into the blank holes in both aprons so that I could keep the hood hinge mounting surfaces right at 40" apart. Since I have my vertical laser level, it's easy to center them up with the laser at 20". Then I needed to set the mounting surface to 90 degrees (vertical). I had to clamp the top in position then force the bottom outward by a good 1/4" to get it to be vertical.
20191226_112125 by 7T02S, on Flickr

Here you can see how misaligned the three holes are in the mating flange of the shock tower. I'll just ream the holes out later.
20191226_112300 by 7T02S, on Flickr

Passenger side needed the same treatment by forcing the bottom of the hinge mounting surface outward to get to vertical. Once I had the vertical set, I then plug welded the upper and lower plug weld holes on the firewall flange. That sets the angle to be final. I was happy with that the flanges were pretty much flush with the firewall (or at least close enough to bend the flanges a little to match). The three mating holes in the shock tower were also way off, so I'll ream those out too.
20191226_131921 by 7T02S, on Flickr

Then I spot welded the forward top surface of the aprons to the shock tower mating surface. You can see them in blue.
20191226_174044 by 7T02S, on Flickr

2. I even got the transmission crossmember positioned and final welded in place. This sucker isn't going to budge!

Here are the plug weld holes in the crossmember. I added four to the mating top surface on the frame rail extensions. The material is pretty thick on both the CM and the FRE's. The thickness is actually the same, so it didn't matter which I used for the base in the plug weld interfaces. I compared the FRE's with my old ones, and it's shocking how thin the material was for the stockers.
20191226_164306 by 7T02S, on Flickr

Here's the top after grinding down the four, upper plug welds.
20191226_173045 by 7T02S, on Flickr

Here's a view of the bottom final welded in place. You can see my dimensions too. I placed the rear surface 4-3/4" forward of the back edge of the holes on the underside of the FRE's. That was just for reference for me. I actually referred to my old parts and measured to the front surface of the crossmember to some of the steering holes in the frame rails. I also compared this to a 31-3/4 dimension I found on an old thread - this is the point-to-point dimension from the lower engine mount hole on the shock towers to the mounting holes of the lower transmission bolt in crossmember, equal on both side. Note that I have those crossmember bolts cranked down tight and that I clamped a bar across the top of the FRE's to keep things from moving around while welding. The upper transmission crossmember, being U shaped is pretty bendy without the lower member bolted in place.
20191226_173106 by 7T02S, on Flickr
61 - 80 of 136 Posts