Entry: 4/10/06 - Today I started on a new, unplanned phase, patching the rusty sections on the driver's side front fender. The next logical step must be mounting the front fender permanently to fit the final gap on the front edge of the door. I started by using the torch, chisel and wire brush to get all the strip body caulk off the fender mounting flanges and assessing the rust situation. There is a rusted out section of the fender flange from the back corner of the trunk opening and over the first 5 bolt holes in the cowl towards the front of the car. The rot area is the most horizontal section of the weatherstrip lip where water must have pooled over time.
A quick review of the factory manual has a nice detailed diagram of the fender flange profile. There's an extra little lip pressed below the actual hood gap edge to allow extra material to adjust the height and gap width and I definitely want to keep that detail in my patch panel so I can eventually make the hood gap a perfect 4 mm to the factory spec.
I decided to make a tool to use in my shop press to stamp the same size reinforcing rib in the patch section as found on the original fender flange and join the patch panels at the square hole for inserting the extruded nut, which will make for the smallest welds.
The tool worked very well and I was able to stamp out 5 matching flange patches that will be welded end-to-end to replace the rotted sections. I hope to be able to plug weld this patch to the back of the existing hood lip and then graft the pieces together so the patch is only visible from under the fender and virtually identical. Besides some rot at the base of the fender where it bolts to the rocker panel, it is in relatively sound shape and should be a good solid repair that won't have any lurking rust bubbles waiting to pop through the new paint when I get done.
Entry: 4/11/06 - Today's job was to cut out the rotten fender flange sections and weld in the patch panels I stamped out yesterday. I thought an "autopsy lab" photo of the rotted-out sections of the flange, numbered to correlate to the patch that replaced it would be interesting to look at.
By the end of the day, all the patch panels are spot-welded into place and ready for some fitting to the cowl before further welding should take place. A coat of 3M weld-thru primer shows lots of details of how the flange will need to be further "adjusted" with hammer and dolly. Some adjustments to the fender bolt holes might also be necessary to get a perfect alignment and hood gap. I'll shim and fill any gaps between the flange and cowl with 3M seam sealer if necessary. Not a big worry as this whole area is hidden under a piece of rubber weatherstrip. I think enough detail has been retained that it will be impossible to detect this repair once a thick coat of the Wurth underseal has been applied to the underside.
Entry: 4/12/06 - The first task today was dressing the spotwelds done yesterday and test-fitting the new fender flange to the cowl. Believe-it-or-not all the holes lined-up perfectly and the gap is uniform, all I can ask for at this point as alignment with the hood will take a bit of adjustment since all the 'U' fold extruded nuts have been removed from the flange so they're all needing alignment when installed. After the successful test fit, I finished welding the flange seams up between the spotwelds. Once the welds were all dressed, I started the dirty job for the day, chemical stripping of the entire fender. I took about 5 coatings of stripper to get all the traces of paint off the fender but the result is a beautiful, mostly damage free expanse of healthy sheetmetal. The only filler is in the area just below the headlight bucket.
I decided it would be best to wire brush all the surface rust to see which is actually due to rust-thru. The only areas I could find that will need some patching are right behind the fuel door where the fender mounting bulkhead has trapped moisture from dirt accumulating there and the obvious rot in the bottom in the rockerpanel area. A quick wipe-down with thinner to remove all traces of the chemical stripper and a coat of 3M weld-thru primer finished the day's tasks. Tonight I can admire a newly re-built fender flange with absolutely no rot and retaining the ability to use the original fastening hardware!
Entry: 4/14/06 - Today I tore into the rotten area at the back lower edge of the drivers side fender where it attaches to the rockerpanel. I quickly knocked out 2 patch panels, one for the inner support structure and the other for the actual outside sheetmetal.
As you can see in the following photos, the first shows the inner structure patch is welded-in, welds dressed and coated with some SEM Rust Seal to seal any remaining rust pits in the metal surrounding the patch welds. The inner structure was only rotted in the center section, the pinch lip at the back edge and the bulkhead where it bolts to the cowl were solid with just a few deep pits remaining after some spot blasting. The second photo shows the outside sheetmetal patch is all fitted and ready to weld in, the gaps in the butt weld seam will close up when I clamp it tight. I will maintain the use of the pinch seam at the trailing edge of the fender so it can be fitted to the door gap once the fender is bolted into position on the cowl.
Entry: 4/15/06 - Today I finished the repairs on the lower rear rockerpanel area of the drivers-side front fender. The tasks included fitting the outer sheetmetal patch and welding it in using the same "series of spotwelds" technique as I used on the door shell and rear quarterpanel. This time I took the weld finishing work to the next step, dressing the weld using my disc grinder and Dremmel tool. After a coat of 3M weld-thru primer you can see where I'll need to do some minor hammer-and-dolly work before the seam is ready for a skim coat of filler. The inner mounting flange weld has been ground-down only the amount necessary to clear the mating surface with the rockerpanel. Since this weld is completely hidden, cosmetic detail work was unwarranted. The key thing is that the pinch seam on the back edge is still loose, which will allow me to do further forming and positioning of the edge and bend to the rockerpanel once the fender is back on the car. Using the actual cowl of the car will provide the bracing necessary before a couple spotwelds can be made in key locations along the pinch seam to hold everything in place. I am really happy with how the pinch seam's "roll" lined-up at the seam with the original one.
Entry: 4/16/06 - My curiosity about the amount of rust waiting for me in that upper cowl area behind the fuel fill door got the best of me today. I did a little prospecting with the cut-off wheel of my Dremmel tool, cutting slightly larger sections of sheet metal out starting at the rot-thru holes. I kept cutting until the back side of the sheetmetal piece was without any significant rust pits. It is obvious the body caulk had eroded away from the inner fender and wet dirt had accumulated in the lowest lying sections and been allowed to pool and remain damp. The metal on the inner support panel was deeply pitted and had a couple rot-thru areas I had to cut out. On this repair I think I'll do as much as I can to stabilize and seal the remaining rust pits on the interior sheetmetal before welding a patch on the outside sheetmetal. Once I've got the outside all dressed and hammer formed back into the original shape, I'll pour epoxy resin into the cavity to seal up the entire area from the back side and further seal the rust neutralizer I'll treat it with first. I think this approach will provide a good long-term solution as allowing an air cavity will give moisture a chance at that rust again. I'll use a liberal amount of 3M seam sealing caulk to close-off the gap between the inner and outer sheetmetal on the front side.
Entry: 4/17/06 - The tasks of the day began with spot-blasting the rust pits on the sheet metal that will be behind the patch. While a coat of SEM Rust Seal to the blasted area was drying, I cut out a patch from a blank sheet of 20-gauge sheet metal. The final product, after much pounding in the lead shot bag and hand fitting looked pretty enough to photograph.
I patiently used the "series of spotwelds" technique to spread the heat around the patch area. I went ahead and performed the finish dressing on the weld and gave the entire area a fresh coat of 3M weld-thru primer. On the inside of the entire fender attachment flange a nice even coat of SEM Rust Seal was applied using compressed air to make sure it reached all corners between the inner and outer panels of the rear end of the fender. I'm pretty pleased with how the patch blended into the existing contours. There was a little warpage and a skim coat of filler will be required to finish the repair but nothing outside acceptable bodyshop practices.
Entry: 4/20/06 - Over the last couple days I've been stripping paint and filler off the area under the front headlight and inside the horn grill / turn signal buckets. The deep rust scales are all removed and the remaining rust pits have been neutralized with SEM Rust Seal. The horn grill area is good clean metal and the only area that has sustained any severe rust damage is the floor of the turnsignal bucket. In the early production fenders, this area is sealed air tight and prone to rust. Fenders produced '68 and later modified this area to be open on the back side and better able to dry out. I really want to preserve this original 4-screw horn grill fender so I had to resort to reinforcing the thin, hole-riddled area in the back edge of the turnsignal bucket with metal window screen and JB Kwik Weld epoxy, which worked very well. After that patch had set-up, I spread a very thin layer of epoxy over the entire pitted floor of the turnsignal bucket with the goal of creating a waterproof barrier to protect the rust sealed pits. I heat the JB Kwik Weld and position the fender so the bottom surface is perfectly horizontal to allow the epoxy to flow over the surface and settle into the pits resulting in a very even surface that preserves the original pressing details. In addition to the fender work, I've also been filling extra holes from the foglight relays in the drivers-side cowl of the car and patching the undercoating so that work will be done when I'm ready to mount the fender for final fitting and cosmetic bodywork.
Entry: 4/21/06 - Work on the drivers-side fender's turnsignal bucket continued today with more cleaning and rust sealing on the backside of it. I'm now thinking a good liberal coat of black "Hammerite" paint would be just the ticket for sealing the treated rust pockets. An additional coat of Wurth high-build underseal on the wheelwell side would provide an additional barrier from moisture. The inside would get an additional coat of Bahama yellow enamel when the car gets painted. All-in-all there would be many layers of moisture protection to keep the rust from re-activating. I did get the cowl work completed and ready to mount the fender when I get done with it. The headlight wiring conduit tube is all restored and painted and the trunk weatherstrip lip / fender flange has been prepped and painted with black Eastwood Company's Rust Encapsulator product. Detailing the front suspension pieces will wait until I disassemble and media blast them while I'm doing the disc brake refurbishment.
Entry: 4/22/06 - Today's effort was spent on getting the remaining details completed on the drivers-side front fender that are easiest done while off the car. I'm eager to get back to fitting door gaps and the other cosmetic work to make the rockerpanel and door rust repair closer to paint. I ended-up using black "Hammerite" to seal both sides of the turnsignal bucket and the bottom of the headlight bucket too. The degree of rot in the turnsignal bucket is far enough along that I would replace the whole floor pressing if it was available as a replacment part. Since that option isn't possible, stabilizing the rust and sealing it with epoxy and "Hammerite" paint is the next best option. I'll keep an eye out for a better turnsignal bucket on a fender in my junkyard and swap-show travels and stash it away for a rainy day when the front of the car needs a fresh coat of paint. I'm much more worried about eradicating all the rust in the core part of the car and must remind myself that the fenders are bolt-on replaceable. What I have now is a factory original fender that has been heavily patched in such a manner that no surprise rust bubbles will pop-up and mar the paint job. I'm also taking extra effort to save the original features, and in light of the overall project, this one little "glass patch" a very small issue. The following photo shows the black "Hammerite" and the old damage repairs that were hidden under the filler and will be needing a re-do once back on the car. (EDITING NOTE: Later, in December, I re-thought the black "Hammerite" paint idea on areas that will be painted Bahama Yellow and stripped it back off the headlight and turnsignal buckets because I will be using a urethane primer which will seal the metal like the "Hammerite" but won't run the risk of causing "lifting" of the paint because it's not compatible with the PPG paint system I ended-up using!)
Entry: 4/24/06 - Today's work began with finishing the last task that had to be done before mounting the fender, media blasting the area inside the fuel filler opening. Weather in Seattle was perfect today for outdoor blasting and the job went quickly. I gave the freshly blasted area a couple coats of red oxide colored primer and then masked it off and gave the entire underside of the fender a fresh coat of Wurth high-build underseal. As the following photo shows, once the undercoating dried, I installed the original 'U'-fold extruded nuts and prepared to test-mount the fender.
I used the new Porsche cowl seal to make sure the right spacing from the cowl was established and proceeded to insert the bolts starting from the cowl and working forward and down the flanges. It took a little pounding and coercion, but the new bottom edge formed pretty much as perfect as I could hope for. All I need to do is make a few spot welds along the pinch seam to hold it in place.
Once the fender was bolted tightly into place, I was able to break-out my newest toy, a spot stud welder that allows me to weld a pin into dents and pull them out with a slide hammer. The following photo shows my first attempt with the tool, pulling a deep dent in the top of the fender. I was able to pull the dent right out! In the following photo you can also see the fit of the Porsche cowl seal prior to filling the seam that runs along it from the rust repair patch I welded in there.
Entry: 4/25/06 - Things started out going very well today as the work on the door gap and dressing the welds on the door and rear quarter panel picked back up where it left off prior to the fender work. The patch panel on the lower door skin had a slight inward warp along the weld seam and I thought if I could push it out, I could make-up about 1 mm of lower door gap. Getting to the seam from the inside proved impossible, but my new stud welder and slide hammer worked out perfectly and as you can see in the following photo. The studs attached on or just below the weld pulled the surface back to flat and will require minimal filler. Better yet, the movement of the door skin metal did close the lower gap to the desired 4 mm. Now for when the day went bad. I was just getting started with my MIG welder on filling some pin-holes in the rear quarter panel weld and it started cutting out before quitting entirely. It seems my home-made 220-volt extension cord had come apart in the plug and shorted. Long story short, the breaker on one of the two circuits in the breaker box seems to have fried and I have to fix that problem before I have a welder that works. I can only hope that I didn't damage my welder in the process... I would think its circuits are protected but only time will tell. Oh well, there are worse things that could have happened, like a fire!
Entry: 4/28/06 - I got the 220-volt breaker fixed and wrapped-up the drivers-side work. Here she sits, welds dressed and primed with 3M weld-thru primer and ready for the last bit of hammer-and-dolly work and a thin layer of filler to hide the patches. I look forward to repeating the same degree of work on the other side.