Body Panels, Prep for Bodywork

Today I spent some time preparing the body panels that I removed from the tub. This involved mechanically removing any remaining spots of paint as well as any adhesive or other remaining surface rust, then sanding the remaining paint smooth and washing each panel one final time to remove any paint stripper residue. Finally, I stabilized the metal so it will not immediately begin to rust.

I started with the trunk lid. The top was fairly well stripped, but the underside had a full coat of paint as well as some glue residue around the edges of the lid where the trunk seal-gasket had been glued. Originally on the roadsters the rubber trunk gasket was mounted on the lid itself rather than on the body. Here are shots of the top and underside of the trunk lid after stripping:

Here is a close-up of the glue on the lid. I took the lid outside and removed the glue with a wirewheel mounted in my drill. I also hit any rusty spots or other areas where necessary.

On the inside of body panels I intend to leave the existing paint and just paint over it. However, I needed to sand the paint to give it some “tooth” as well as remove any remaining junk on the surface of the paint. I hand-sanded using 100-grit paper.

Then I just washed down both side of the panel using the hose, applying some Simple Green and giving a good scrub with a scouring pad. Then I applied more Simple Green and gave the entire panel a final thorough rinse. Here is the cleaned trunk lid.

Next I moved on to the driver’s side door. The passenger side will have to wait because it has a big dent on it that will require further attention. On the driver’s side I used the wirewheel on the outside to remove any remaining small spots of paint.

Then I did the same on the inside, removing any rust or adhesive and doing a sanding on the paint. I washed the door completely as with the trunk lid.

And I followed the same procedure to clean up the hood.

In general stripping a car to bare metal is risky because bare steel is apt to begin rusting immediately upon being exposed to water, or even to any humidity in the air. Invisible surface rust can begin forming and then fester underneath a new paint job, eventually leading to bubbles and even structural damage. To try to prevent this I am treating the bare sheetmetal with a Metal Prep product. This kind of product is an acid-etch that chemically removes rust and leaves a thin protective coating on the metal that temporarily discourages rust. The etch also has the additional benefit of providing some “tooth” to the bare metal which will help paint adhere. I bought a gallon of Metal Prep from Halon Marketing in Pennsylvania for around $28. I apply the stuff from a spray bottom which I clearly labeled (the liquid is green, so I wouldn’t want to confuse it with Simple Green) and I always wear gloves and safety glasses when I work with this stuff because it is acid after all!

On the truck lid, I first sprayed the surface, then agitated it with a scouring pad to remove any surface rust. When the Metal Prep does interact with rust it can create fumes so I always make sure there is plenty of ventilation when using it.

Then I applied another light spray to the surface, and wiped all of the liquid away using a shop towel. I’ve found less is better provided I cover the metal, because over-applying the metal prep can create runs that need to be removed later.

I followed the same procedure on the door and then the hood. Spray and then scour…

Then spray again and wipe off the excess.

Here are a couple of pictures of the hood after it was treated.

I repeated the process on any bare metal exposed on the inside of the trunk lid, door, and hood.

Stripping the Tub, Day 3

Today I spent some more time mechanically stripping the tub, including the front end and engine bay. I ended the day by giving the entire tub another thorough cleaning to remove any residual chemical stripper and paint dust.

I began on the cowl area in the front and the top area in the rear. I used a 3M Clean & Strip scotch brite disk on my drill to remove much of the remaining paint.

Next I worked on the rear fenders and rockers.

And then I turned my attention to the firewall.

And the engine bay.

First I removed the grill cross-supports, top and bottom, using a 1/2″ socket.

I spent some time using the 3M Clean & Strip disk and then did some hand-sanding on the hard-to access areas.

Here are the fully stripped left and right sides of the engine bay.

Where the paint was too difficult to remove altogether, I used 150-grit sandpaper to sand it smooth and feather it into the areas where the bare sheetmetal was exposed.

I also did some hand sanding inside the trunk.

On the interior of the body I spent some time with the wire wheel. I removed some remaining adhesive areas and seam sealer from the rear.

And also from the transmission tunnel.

I turned my attention to the exterior of the body, specifically the areas under the front fenders. The areas at the side of the engine bay where the hood rests were a bit rusty, so I used a Norton abrasive disk to remove the corrosion.

And I did the same on the area underneath the front fenders and the lower rocker panels.

The areas under the fenders came fairly clean, but the most serious rust was on the lower rocker panels. This area will most likely require a patch.

At the end of the day I gave the entire tub, top and bottom, inside and out, a good cleaning. I wet the entire body and sprayed it with Simple Green. Then I used scouring pads to go over the entire thing.

Inside the very fronts of the rear fenders I found an area just ahead of the rear wheel wells where a lot of dirt had gathered over the years. This could get damp and promote rust, so I attempted to clean it out. I repeatedly sprayed inside with water, and then used my hand to try to loosen the fine dirt inside. Then I used my wet-dry shop vacuum to suck out the water and mud mixture. After repeating this several times I got most of the dirt out from each side.

Here are some pictures of the stripped tub after the cleaning. From the front:

From the left side:

And from the rear:

After drying away any standing water with my vacuum and a towel, I allowed the car to air-dry under the warm Texas sun for several hours. In the evening I rolled it back into the garage and ran the dehumidifier overnight in order to evaporate any hidden dampness from the bare metal.

Stripping the Tub, Day 2

Today I spent the full day stripping paint from the body. I finished the rear portion and worked my way forward to the front of the body using the chemical stripper and then spent some time beginning to mechanically strip what was left.

I decided to try a different variety of paint stripper. This one is called Aircraft Stripper, also made by Kleen Strip. I have heard good things about it and according to the label it is formulated specifically for enamel paints. It also is low odor, whereas the other stuff was pretty strong. I bought two quarts from Walmart for about $7 each, which comes to about what a gallon of the other stuff costs. This stuff was thick and yellow, unlike the clear/whitish other stuff.

And it did work well; I applied a coat to the rear and immediately began to hear a crackling sound as the chemical went to work.

I worked my way up the left side of the car, spot-treating the rear fender and then covering the rocker panel.

Then I applied it across the front cowl area.

And back around the right rocker panel and right fender.

The Aircraft Stripper was low in odor, but definitely strong stuff. I accidentally bumped my knee into an area I can coated in stripper and immediately felt an intense burning through the denim of the jeans I was wearing. I had to change my pants and noticed a visible welt on the skin of my knee underneath.

Then I returned to the front of the body to work on the engine bay. I applied masking tape to prevent stripper from seeping into the seems and applied stripper to the engine bay.

After 30 minutes I scraped the paint off the rear and cowl, using a plastic paint scraper.

And the rear fenders and rocker panels.

And I scraped the paint from the engine bay.

Next I applied a first coat of stripper to the firewall and apron. I was careful to avoid the seems as I had done in the engine bay.

A final application and the rear and top areas were stripped mostly to bare steel.

As were the fenders and rocker panels.

And the cowl and engine bay.

I washed the chemical stripper off the tub and prepared to begin mechanical stripping to remove the balance of the paint.

On the right rear fender there was clearly some damage that had been repaired using body filler. I removed the bulk of the filler using a wire wheel on my drill. There was a rust hole on the right fender lip that had been filled through-and-through with filler.

Here is a shot of the rust hole on the right fender and similar damage on the left fender.

I removed paint from the rest of the left fender using a 3M Clean & Strip disk.

And I did the same to remove the paint from the rear panel.

I used my wire wheel to clean up the recessed area where the hoodpins had been mounted on the body.

Then I spent some time using the wire wheel on the windshield frame. I began on the vertical posts, removing any remaining adhesive or gasket material.

After doing both sides I worked my way across the top removing the adhesive and foam remaining from the upholstery pieces.

The windshield frame came fairly clean.

The final thing I did today was to work on the front apron, removing the body filler and remaining paint using a wire wheel. There was a considerable amount of damage to this piece, presumably from the front-end collision I suspect is in the car’s history. I may try to replace the apron rather than repair it, given how flimsy it is.

Stripping the Tub, Day 1

Today I got started stripping the paint off the body. I began at the rear and worked my way forward. I got as far as applying several coats of chemical paint stripper to the rear panel and rear fenders. The stripper I used was ordinary paint stripper from Kleen Strip. I have used this on several other jobs in this restoration and it works well enough with multiple applications. It is strong, though, so I always wear thick rubber stripping gloves and eye protection. I have accidentally splashed it on my skin before and it burns immensely.

I began on the rear panel of the body. I brushed on a liberal coat of stripper moving in one direction only (not doubling back over an area), per the instructions on the can.

After applying a full coat to the rear panel I did the same on the left and right rear fenders and the top area above the trunk.

The most important thing is to allow the chemical stripper time enough to work on the paint. Here are some photos taken after ten to fifteen minutes (the instructions advise allowing a full 20 to 30 minutes). The rear and top area:

And the right fender:

And here are some taken after a full 40 minutes. The rear and top:

And the left fender:

At which time I scraped the paint shavings off using a plastic scraping tool designed for stripping paint. I started on the rear, then did the top.

And then did the fenders.

Then I applied a second coat of stripper to the rear and top.

And to the rear fenders.

After waiting 30 minutes and scraping off the paint, I applied a third coat.

After three applications I was low on paint stripper. I scraped the paint off the rear and top.

And the fenders.

Much of the paint came off, but a lot remained at the end of the day. I cleaned the areas I had applied paint stripper to very thoroughly using water, Simple Green, and scouring pads to rinse off the chemicals. Here is the rear and the top after cleaning.

And the left fender.

Stripping Body Panels, Day 3

Today I finished up mechanically stripping paint from the remaining body panels, including the hood and left front fender.

Here is a shot of the hood after the chemical stripping:

I began on the front edge lip, where there was some denting, some damage, and the mounting holes for the D A T S U N letters had been covered over with body filler. I went to work removing the filler with a wire wheel on my drill.

Most of the filler came off with no problem.

One the top right edge of the hood there was also some damage that had been filled.

And on the opposite side there was a small area as well.

I removed the paint from the scoop using a 3M Clean & Strip Disk.

Then I moved up the opposite edge of the hood doing the same.

The hoodpin areas for some reason evaded the chemical stripper, but where no match for the stripping disks.

I also removed the paint from the other edge between the hood and scoop and up that side.

Here is the hood fully stripped.

Next I moved on to the left front fender. Here are a couple of shots of the fender before and after the mechanical stripping. I used the 3M Clean & Strip wheels exclusively. From the side:

From the top:

And from the front:

This fender was in decent shape with minimal body filler.

Stripping Body Panels, Day 2

Today I continued the work of stripping down the body panels, including finishing the chemical stripping of the trunk lid and hood, as well as the front fenders. I also spent some time mechanically stripping the paint that the chemical stripper wouldn’t remove.

I decided to give the trunk lid another coat of chemical stripper. I put down some plastic wrap over the paste in an effort to prevent it from evaporating so the stripper could penetrate the finish for a longer period of time.

Then I began to work on the right front fender. I applied a thick coat of stripper using an old paintbrush.

I gave the stripper half an hour to work on the fender, and spent some time cleaning up the dent repair area on the right door. I used a wire wheel on my drill, which was fairly effective at removing the body filler.

The chemical stripper raised a lot of the paint off the surface, which I scraped off using a plastic paint scraper.

However, the paint I removed must have been an outer layer, because there was still red paint covering the metal after the first stripping.

I applied a second coat of stripper to the right fender and then went back to work on the right door, which had plenty of paint remaining on it. To mechanically remove the paint I used a 3M Clean & Strip wheel on my drill. It was pretty effective at removing the stubborn paint and cleaning the bare steel. I bought the 3M Clean & Strip wheels from Fastenal for around $10 each. I bought three to start with.

After second and third coats of stripper, some of the paint was coming off the right fender.

As I was discovering that mechanically stripping paint takes considerably more effort (though less time) than chemically stripping it, I gave the hood an trunk lid another coat of chemical stripper.

Here is the front right fender after three iterations of chemical stripping. I washed the fender with soap and water to remove any leftover stripper and allowed it to dry in the sun. On the front by the headlight opening there were clearly some body filler repairs. All the evidence points toward a minor collision at some point on the front right of the car.

I began a routine where I would apply stripper and then spend 30 minutes (while it worked on the paint) with the drill and wheel removing paint between coats. I started with the trunk lid.

I held the wheel to the surface with light pressure, moving it in a back-and-forth or small circular motion across the paint. It took the panel down to bare metal quickly.

After working on the trunk lid I went back to apply chemical stripper to the left fender.

And I went back to work on the right fender while the chemical stripper worked on the left.

I removed most of the paint from the lower portion of the fender. I left the paint on the very lower edge, as the rust down there is going to require a patch of some sort anyway.

After 30 minutes the chemical stripper had begun to remove much of the paint from the left fender.

I scraped off as much loose paint as I could and applied a second coat.

Then I went back and worked on mechanically stripping the right fender. I used the Clean & Strip disk to remove the paint along the top edge of the fender.

Then I moved on to the front of the fender. The headlight area had a lot of body filler. I started on the outside of the headlight, using a wirewheel to remove the filler.

The filler came out after several minutes.

The arch on the inside of the headlight had a thicker application of filler. One reason I am removing the filler is there could potentially be rust underneath it, as there was in this area.

The depth of the filler was 3/8″ to 1/2″ in some areas, as I could see by penetrating down to the underlying metal. Additionally, there were several holes underneath which had been used to reverse the dent (pull the metal forward) but were never patched over. These holes could allow water to infiltrate the filler from the inside and cause corrosion in the metal.

After getting down to bare metal I was able to pop off some of the filler in larger chunks, using a screwdriver and a mallet from behind.

I pried off much of the remaining filler, which was faster and lust dusty than using the wire wheel.

There was even filler patched into the gap between the fender and the headlight bezel, which I removed.

The last thing I did was to mechanically remove the remaining paint from the left door.

I washed up the hood and left fender with soap and water to remove the chemical stripper and called it a day. After the panels had dried outside for a few ours I moved everything into the garage and ran the dehumidifier to discourage any moisture from causing rust on the bare sheet metal. I still need to mechanically strip the other (left) fender and hood.

The sheet metal is in fairly good condition with a couple of exceptions. I will need to address the rust at the bottom of the fenders, probably with patch panels. I will need to do some minor repairs on the hood, drunk lid, and left door and fender. And I will need to undertake more substantial repairs on the right door and fender as well. Other than that, everything seems pretty solid.

Stripping Body Panels, Day 1

I spent the rest of today beginning to strip the paint off some of the body panels, including the doors, trunk lid, and hood. I made good progress but there is plenty of work remaining for tomorrow.

I began with the left door. I am using the same stripper I have used on other parts of the car, a product called Kleen Strip, which I have found to be highly effective. It is also highly toxic, so I took the proper precautions of wearing safety glasses and thick rubber stripping gloves at all times. I worked outside so there was plenty of ventilation; the fumes from the stripper can be strong. After getting some small drops on my sandaled feet and feeling an immediate burning sensation, I put on long pants and shoes despite the hot weather. Safety first!

I applied the thick, pasty stripper using an old paintbrush. I applied a liberal coat, putting it on thick and moving only in one direction to lay it down. The better the seal the stripper creates against the surface the better it will work and going back over areas breaks that seal.

After a few minutes the paint began to wrinkle off the metal. I allowed each coat of stripper to work for 30 minutes before going back to a panel.

So I walked away from the left door for 30 minutes to allow the stripper to work. I spent that time preparing the hood and trunk lid for stripping. The hood had two metal circles for the hoodpin holes, which I needed to remove. The hoodpins were not an original feature, so I am removing them altogether. The disks were held in place by three screws, which I removed using a Philips-head screwdriver.

I removed the cover revealing a hole in the sheet metal around the size of a dime. I should be able to patch those holes.

Next I removed the molding from the front of the hood scoop. I tapped it off using a rubber mallet and a plastic scraper to prevent any damage to the molding. It popped right off.

Here is the trunk lid, outside and inside.

I removed the molding from the rear edge of the lid by removing the three Philips head screws.

Next I pealed off the rubber gasket from the inside of the lid. It came off without too much resistance.

At that point around 30 minutes had passed so I returned to the left door. Much of the paint had separated from the sheet metal, and I began using my plastic paint scraper to scrape it away.

I gathered up the paint scrapings by scraping them to the center of the panel and then disposed of them.

Here are two views (bottom and top) of the door after the first application of paint stripper.

The door had a couple of areas where body filler had been applied, including this one.

I applied a second coat of paint stripper, waited 30 more minutes, and repeated the process.

After removing the second coat of stripper the left door was fairly clean. The exceptions were two areas: a horizontal line under which the side molding would go and a small area under where the mirror would mount. I think that the car was painted at some point and these areas were not, and the original finish under there was more difficult to remove.

I moved on to the right side door. I applied the first coat of stripper and waited 30 minutes. The paint did not come off very easily, and there was clearly a large body filler repair on the front half of the door.

After applying the first coat of stripper to the door I did the same to the trunk lid.

After 30 minutes I went back to working on the door. More paint came off revealing the body filler.

I scraped off some of the body filler, which had been softened by the chemical stripper. Also a large patch of paint on the other side of the door would not come off.

Here is the trunk lid at the end of the day after two iterations of stripping. I cleaned off the doors and trunk lids with soap and water to flush away any remaining stripper. Then I allowed the pieces to air dry for the rest of the afternoon in the heat.

And here is the hood after one coat of stripper and after washing it thoroughly.

There were a couple of areas that had been repaired.

After washing the body panels and allowing them to dry outside, I moved them into the garage overnight, where I turned on my dehumidifier to help dry up and moisture.

Body: Hood Undercoating Removal

This afternoon I spent some time removing the last of the tar undercoating from the body panels. The hood had some undercoating on its inside, presumably to protect the topcoat of paint from the engine compartment heat and to keep the engine noise down.

The hood I worked on (red) is the original hood that came with the car. I previously purchased a good-condition (white) hood that I was going to use as a replacement because of some damage to the original. However, I have since revised my thinking and intend to use the original hood because I think I can repair it and it is a “sure thing” in terms of fitting properly.

I removed the tar undercoating by heating and scraping it off and then using a solvent to remove any remaining tar coating the metal. I began in the lower left corner of the hood. I used my heat gun, applying it for around ten seconds about two inches from the surface, then using a small metal scraper to get down to the metal.

The coating came off pretty quickly. I moved up the left side and removed all the coating. In the picture below, right, I can distinctly see the image of Darth Vader in the lower portion of the remaining undercoating (right side, not yet scraped).

I scraped the other half of the hood and sprayed on the De-Solv-It solvent I have been using to clear off the residual tar.

Then I scrubbed the metal with my stripping brush and wiped away the tar residue. The solvent was very effective.

Body: Door & Fender Undercoating Removal

This morning I scraping the tar undercoating that remained on the insides of the front fender panels and inside the doors. The undercoating was originally applied to protect the metal surfaces from rocks and road debris and, in the case of the doors, to provide some noise reduction.

I removed the undercoating the same way I removed it from the underside of the body, by heating it and scraping the bulk of it off, then using a solvent to remove the remaining residue to reveal the clean metal underneath. I began with the doors.

Most of the undercoating was behind the opening and on the outer door skin. I heated it with my heat gun, set on high, for about ten seconds.

Then I scraped the covering with my small metal scraper. I removed the lower half of the coating first.

Then I rotated the door 180 degrees and went to work heating and scraping the upper area.

After about fifteen minutes I finished and repeated the process on the other door.

The insides of the front fenders were also covered in undercoating.

I started along the rear edge of the fender, heating and scraping.

I worked on the lower edge, revealing a considerable amount of rust in the sheet metal. This is a typical problem area in these cars.

Then I worked my way up the rear portion of the fender. The material was actually much easier to remove where it was thickest.

Then I scraped along the middle of the fender towards the front.

Here is the front of the fender before and after I removed the undercoating.

Here is the fender finished. Each fender took around an hour to scrape–the headlight areas went fairly slowly.

In order to remove the remaining tar residue I used more of the De-Solv-It citrus solvent that worked so effectively on the underside of the body. I sprayed the tar-covered areas liberally and allowed around 30 seconds for the solvent to soak in. I did the doors first.

Then I scrubbed the area with a stiff stripping brush, following that with a preliminary wipe with a rag.

Next I made a second application of the solvent and wiped the metal clean.

Next I moved on to the fenders. I used the same process. First I sprayed the inside of the fenders.

Next I scrubbed and wiped away most of the tar.

After another application of solvent and a final wipe with a clean rag the fender came clean.

Body: Undercoating Removal, Part III

This afternoon I finished removing the undercoating by removing the remaining tar residue from the sheet metal. The black coating remaining was similar to that left after I removed the coating from the floorpans above. I tried a new solvent, called De-Solv-It which is citrus-based and doesn’t have a noxious smell, though it does get to you after a while. This stuff came in a spray bottle which made it suitable for applying to the underside of the body. I bought three 12 ounce bottles ($4 each from Walmart–in the groceries section, not the paint-stripper section) and used almost all of it to complete the job.

I began with the areas underneath the front fenders. Despite the orangelike smell I put on my heavy gloves to protect my flesh and wore safety glasses.

I sprayed the area liberally with the solvent, waited thirty seconds, then agitated it with a stiff stripping brush.

Then I gave it another coating of solvent and then wiped the residue off using a shop towel. The surface came pretty clean.

I determined I could work relatively large areas at a time in this manner.

I started on the underside, going to the driver’s side first. I worked the entire floorpan area in one pass.

Here is the rear section of the floorpan, before and after.

Then I did the passenger’s side, and moved on to the transmission tunnel.

Here is the passenger side.

Next I proceeded backwards toward the rear, under the rear shelf and the trunk area. I sprayed, waited, scrubbed, sprayed, waited, and wiped.

The sheet metal came pretty clean using this method.