Body, First Welding Repairs

This afternoon I used my new welder to repair some holes in the body sheetmetal. Welding closed holes is a good place to start to get a feel for welding sheetmetal, because it basically consists of blobbing into and over the hole a lot of welding wire and then cleaning up the mess later with a grinder. If you blow through the sheetmetal, which is easy before you get some experience with setting the voltage and feed-rate to appropriate levels, well then you’ve just got another hole to patch. Also, fixing small holes in the body doesn’t really constitute making structural repairs, so it is okay if the weld penetration isn’t great. For sheetmetal I use the thinnest welding wire I can (.023″) in order to keep the voltage as low as possible.

So after practicing on a lot of 1/8″ steel stock I bought at the hardware store I jumped right in to making repairs in the body. The roadster sheetmetal is very thin, so it is easy to get the weld to hot and melt right through. Trial and error with the voltage set-up allowed me to minimize this. Also, I found it necessary to back up the sheetmetal with a steel plate to effectively thicken the area and allow for better heat dispersion. Finally, I welded in very short bursts, essentially just making a long series of spot welds, which prevented too much heat build-up.

On the driver’s side floorboard there was a small rust-through that I cleaned up using an abrasive wheel. To prevent welding over rust, I used rust-converter on the hole and the area around it. To get a clean weld it is imperative that the metal be completely clean and rust-free.

I wore my auto-darkening helmet, welding gloves, and protective clothing before welding. By making each tack slightly longer in duration (by holding the trigger down sequentially longer each time) I found that he material I had previously deposited would melt into the new tack, creating one single weld-pool and allowing me to control the shape of the repair better.

In the trunk there was a hole by the jack bracket. I used a wire wheel to remove the paint from around the area and did the same on the underside of the body. I started welding up the hole from the bottom, building up tacks from the sheet metal rim around the hole inwards towards the middle of the hole, where tacks from either edge of the whole met.

After building up a lot of welding wire I moved to the inside of the trunk and built up some tacks on that side.

Then I used my Dremmel with a pair of small cut-off disks mounted in tandem to grind down the welding blobs I had created to smooth out the metal.

I quickly realized that the body that I had painstakingly washed so many times was getting covered in grinding dust!

New Welder

I bought a welder. I’ve been anticipating needing one for the project for some time. After doing some research I settled on the Millermatic 135. I have zero past experience with welding but have read a lot and done some practicing since I got the welding set up. I had several criteria when picking out a welder:

  • I don’t have a 220 volt circuit in the garage, so the welder has to be 110 volt.
  • I definitely wanted a MIG welder due to its relatively shallow learning curve and the fact that it could handle just about any project a hobbyist like myself may tackle.
  • I wanted something with shielding gas rather than having to rely on flux-core wire, because everything I’ve read says that gas makes for cleaner and (most importantly) easier welding.
  • I’d like a machine with a coninously variable, rather than discrete, control for voltage and wire feed speeds because I’ve been told that feature makes it much easier to find an appropriate setting for thin sheet metal, which is my primary concern at this point.
  • Subject to the above wish list, I’d prefer to minimize the cost. I’m perfectly willing to pay for a quality tool, but I prefer not to overpay.

So I settled on the Millermatic 135, which has all of the features I’m looking for. I bought the welder from an ebay seller in Indianapolis named Indiana Oxygen Co. (weldingsuppliesatioc) for $566.77, which included shipping to my door. At the same time I bought a 20 cubic foot gas tank from the same seller for $62.87 and some welding wire (one spool of .023″ and one of .030″) and two sizes of tips. All in for the welder, tank, and consumables I spent about $660 for the entire set-up. I actually bought these items in January and have been setting up the welder and practicing since then. Lincoln has a similar welder that I’m sure is just as good.

In order to complete the set-up I purchased a welding cart, an auto-darkening welding helmet, some heavy leather welding gloves, and a set of welding pliers from Haborfreight. I also went to Tractor Supply to get some shielding gas. The gas I got was 75% Argon and 25% Carbon Dioxide. I handed in my gas bottle in exchange for one they had on-hand that was already filled.

Body, Sheet Metal Prep

This afternoon I prepped the body tub’s bare sheet metal to prevent surface rust from forming. I used Metal Prep, which is an acid-etching product that removes surface rust from bare metal and leaves a thin protective coating that inhibits more rust from forming. Regular humidity in the air can cause bare steel to flash-rust, so the coverage afforded by the coating prevents that exposure.

I started in the cabin, where I treated all of the bare metal spots on the rear shelf and on the firewall, areas that were exposed when I removed seam sealer. I also treated the entire floorboard area, which was exposed when I removed the tar undercoating.

I wore rubber gloves to protect my skin from the acid. I sprayed the Metal Prep on using a regular spray bottle, and then rubbed it into the surface using a scouring pad.

Then I sprayed another light coating of Metal Prep and wiped off the excess with shop towels after giving it around a minute or two to work. Drips can be pretty messy, so I am always careful not to use too much.

Here are the final results in the cabin.

I followed the same procedure in the trunk, and in the engine bay.

I also treated the rear panel and both rear fenders. On the picture of the fender you can see some drips that resulted from the Metal Prep gathering in the side-molding channel and then flowing down–that’s what I was trying to avoid.

And I also did the rear shelf and the front cowl areas.

Body, Final Washing

This afternoon I gave the body another washing in order to remove the seam sealer and rust particles, as well as the solvents used to clean up both.

I started out by sanding all of the areas where paint removed, in order to rough them up so the new paint, when eventually applied, will adhere. I used 120 paper and sanded the rear area of the cabin.

I was also careful to sand all up underneath the dash on the firewall.

Then I started washing inside the trunk, where I had sanded previously. I sprayed with the house to wet everything down, then sprayed Simple Green on all the surfaces.

I used scouring pads to scrub all of the remaining particles of seam sealer that had flown off the wirewheel onto the sides of the trunk as well as any of the solvent I’d used to remove the sealer itself. I also made sure to scrub the recessed areas where the drain plugs are in order to remove any rust neutralizer that may remain on the surface.

After the trunk was pretty clean, I gave it several more good rinses with the hose.

The Simple Green is an excellent de-greaser and the trunk came clean and dried quickly in the hot Texas sun.

Likewise I wet down and sprayed Simple Green throughout the cabin, giving every area a good scrub with the scouring pad.

The cabin and the firewall came clean and, after I drained the water, dried quickly.

Here is the underside of the firewall after the final (I hope!) washing.

Body, Rust Removal Part II

This morning I continued to address the rust inside the cabin and, to a lesser extent, the engine bay. Yesterday I used a wirewheel to mechanically attack the rust. Today I used chemical means.

I bought a chemical rust neutralizer from Halon Marketing called Rust Away. The liquid is blue in color and can be used to soak parts, or applied onto rusty areas to convert rust. It uses tannins to convert iron oxide into iron tannate, which is black. I applied it to the footwells of both sides of the floorboards by laying on paper towels and them pouring the Rust Away on. The paper towels held the solution in contact with the rusty spots I was targeting.

The instructions recommend allowing rusty parts to soak for two hours; I allowed for three before removing the still-soaked paper towels from the floorboards. Visually the rust appeared converted.

I repeated the process on the passenger side.

Also the cracked firewall in the brake master cylinder pocket had some rust developing inside. I treated that area by laying paper towels on the engine bay side, then tucking the edges of a couple of towels down into the cracked area.

Then I soaked the paper towels and allowed the solution to work for several hours before removing the towels.

With all of the seam sealer and other adhesives removed, it will be time for one more washing before I begin the bodywork in earnest.

Body, Rust Removal Part I

This afternoon I continued preparing the body for bodywork by starting to address the rust spots inside the cabin.

In the footwells there were several areas where it was clear water had rested on the floorpans and caused rust. Some of this I’d characterize as “surface rust” while some of it was less superficial in its penetration of the metal. On the driver’s side the floorpan was still very solid (thankfully). The worst area was around the drain plug but there were several rusty patches. I began by using a coarse wirewheel on my drill to remove the surface of the rusty patches.

For the most part much of the rust came off leaving pitted steel, but in some areas there was rust I couldn’t get off mechanically.

In one area the metal had thinned enough such that my rust removal opened a small hole in the floorpan. I continued underneath the car with a more aggressive abrasive wheel where the rust was accumulated on the outside of the metal.

I was able to thoroughly clear the rust away from the area around the hole.

And I got the majority of the rust on the underside, leaving just the pitted steel and some rust-colored dust.

On the passenger’s side there were a similar collection of rust spots, though not as bad as on the driver’s side–the rust had not spread to the underside of the body on that side.

Body, Removing Seam Sealer

This morning I began doing the final preparations before I begin bodywork on the body itself. The first thing I did was to remove the seam sealer from within the engine bay, trunk, and inside the cabin.

I used a variety of tools, beginning with a small wirewheel mounted on my Dremmel. I found that using a utility knife allowed me to cut down both edges of the seam and remove the majority of the sealer.

Using these two methods I was able to remove the bulk of the seam sealer from the engine bay.

Next I moved back to the trunk, where I began with the lip where the lid rests against the body. I cut away with the knife and used a flathead screwdriver to scrape the seam sealer up away from the body.

Then I moved on to the inside of the trunk. In there the seam sealer was a black material unlike the white stuff in the engine bay and outside the trunk. In some areas there were big blobs of sealer. I used the wirewheel on my drill to get most of it. It came off in little, sticky bits that sprayed everywhere–all over the nicely cleaned trunk.

After I was finished with the wirewheel most of it was gone, though there remained some knooks and crannies where the round wirewheel could not reach, so I used my utility knife to scrape away at the very corners.

I used my shop vacuum to clean up most of the bits of seam sealer and then did the opposite side.

One the outside edges of the trunk there was more seam sealer along the lower fenders, where the drain plugs reside. I did my best to remove as much of it as possible mostly using the knife.

Then I worked across the lower edge of the rear panel, working across the trunk from left to right.

Inside the cabin there was more black seam sealer all along the seams of the firewall, which I removed.

And along the fronts of the rear wheel wells (and around them) on the rear shelf there was more of the white seam sealer which I removed.

On the floor behind the seats there was more black seam sealer. After removing as much of it as possible using the knife I scrubbed the remainder off using the same solvent I used to remove the tar-based undercoating from underneath the car, called De-Solv-It. I sprayed it on and used a wire brush to scrub away the sealer.

I also used a scouring pad with the solvent. After the solvent had done its job I wiped away the residue using a shop towel.

Overall I got most of the seam sealer removed, and used the same techniques to remove it throughout the car.

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.