Passenger Door Body Solder

Today I used some body solder to attempt to fill in the low spots remaining in the passenger-side door dent. Yesterday I did my best to pull out the dent with a slide hammer and then shrink the sheet metal back semi-close to flush. Here are the pictures of what it looked like afterwards.

My first step was to clean off the dent area to remove the coating left by the Metal Prep I sprayed on and any leftover debris left from the welding and subsequent grinding of welds. I used a 3M Clean and Strip wheel. BTW, those 3M wheels are fantastic for removing paint and cleaning metal without damaging it, but don’t by the ones with a plastic shaft because they will break right off if you try to use them in a drill.

Then I wiped the entire area down with acetone to remove any grease.

The first step in applying body solder is to put on the tinning compound, which binds to the steel and also binds to the solder. The solder itself would not adequately bond to bare steel, so the tin is a necessary intermediate step.

I bought a Lead-Free Body Solder kit from the Eastwood Company; that kit included everything I needed such as tinning compound, a brass brush to apply it, the rods of solder, a wooden paddle to shape the solder after it goes on, some paddle lube to prevent the wood from sticking to the solder, and a nice file to shape body repairs. I went with the lead-free solder because, unlike the lead which was used in the old days for body repairs, this solder can be sanded without releasing particles that would be harmful to breath.

I began by stirring up the tinning compound, and then brushing it onto the door.

After the surface was coated, I began to heat the tin using a small propane torch I bought at Home Depot.

As the tin began to melt, it turned shiny silver and brown impurities moved to the edges. I wiped the hot tin across the surface of the steel with a clean white cotton shop towel.

I moved across the surface of the door heating the tin until it liquefied and then wiping it across, until the entire surface was coated in tinning compound.

Then I washed down the tinning compound, which apparently is somewhat acidic, using warm water until the rag I was using came up clean.

Then I started applying the solder. I used the same propane torch, heating the door and the end of the rod of solder and depositing globs of solder onto the door. Eventually the rod got short enough that it was getting very hot, so I dropped the remaining two inches or so straight into the repair.

Then I used the wooden paddle to try to spread the solder out more flat over the low spots in the door. It was a very inexact way to shape the solder.

Here is a look at the profile of the solder repair.

I worked the solder with the file that came with the kit, which was only marginally useful, so I also used some 80-grit sandpaper to shape the repair. It came into a bit better shape, though far from perfect.

Front Fender Weld Repairs

The last thing I did today was to weld-up some holes in the front fenders. I did similar repairs on the body yesterday. The passenger side fender had some collision damage repairs, and many holes remained where the previous bodyman had pulled out the metal before applying filler. I wanted to seal off these holes in order to prevent water from coming through the back side and causing rust problems down the road.
The front fenders were cleaned previously, so I just spot-welded the holes, building up welding wire from the edges of the metal in toward the center of the holes.

After welding I used my angle grinder and cut-off wheels to grind the repairs smooth.

After that was finished I went back to the body and cleaned up some of the areas I welded yesterday. On the brake master cylinder niche in the engine bay I used a wire cup to clean and remove any welding slag from the metal.

Then I did the same on the front apron around he holes I welded up.

With the metal clean and the rest of the paint gone the apron is ready for bodywork.

Passenger Door Dent Repair

This afternoon I did some amateur metalworking to try to straighten the dent in the passenger side door. The door has clearly been the victim of some kind of collision and when I stripped the paint there was lot of body filler under there.

I plan to do my bodywork in the following steps:

  1. Use body hammers, dollies, slide hammers, and other tools to attempt to pull the dented metal back to flush with, or in some cases proud of, the surrounding un-dented metal.
  2. Use friction and heat to shrink any metal high spots from my metalworking back to a uniform surface.
  3. Fill the majority of remaining voids with lead-free body solder to build up the area, once again slightly proud of the finished surface.
  4. Grind and sand the body solder as flush to the surrounding metal as possible.
  5. Apply the thin coat of body filler, sand, repeat…as necessary to get a perfectly smooth surface.

My goal is to minimize the use of body filler to a thin coat, maybe 1/16 to 1/32″ and to make the repair as strong as possible. Today’s body fillers are incredibly strong and bond very well to metal, but I still think the body solder has an advantage in bonding and strength.

Here are head-on and profile pictures of the dented door.

In order to find the boundaries of the dent, i.e. the low spots, I marked over the surface of the door with a black marker. Then I used a flat sanding block to sand the area, so the low spots would remain dark black.

Here is a shot of the low areas out in the sun where it was easier to see.

Where the dent had been repaired by the previous owner there were a couple of holes in the door skin. I used these and my slide-hammer to pull the metal up. When it became clear that the pulling wasn’t popping the dent out but just forcing up localized areas, I drilled a few more holes in order to pull in more areas.

I kept pulling, and adding holes to get the whole area up flush or slightly above the surrounding door area. The metal had been stretched when the dent happened, and I stretched it up in the opposite direction. No question this was the ugliest part of the repair process.

Next I brought out my new shrinking disk. I bought this shrinking disk on ebay from Wray Schelin, who runs the Metalmeet forums, which are really great for discussing metalwork projects of all kinds including metal repairs. There are some real artists and craftsmen over there. The disk is steel and 9″ in diameter and I paid $35. The edges are bent up so it won’t slice your flesh if you get it too close to your body, which is a nice feature. It is mounted to a large grinder, in my case a 7″ angle grinder from Harborfreight. The grinder should have at least 6000 rpm in order to work effectively with the shrinking disk.

The shrinking disk is used to build up friction on the surface of the metal, specifically on any and all high points, making the metal very hot in those areas. After the heat is built up, the idea is to quench the metal with water. The heating and quenching process causes the metal to shrink. The shrinking disk is large enough so that if you run it along the surface of the metal it will only heat up the high points so eventually they should shrink down flush to the original metal.

Here is the shrinking disk and a picture of me running it over the door.

After running the disk on the surface for 15-20 seconds or so, I quenched the metal by squirting water on it. The metal sizzled and steamed a bit, confirming that the heat was building. I avoided getting the metal too hot, and making it change to red or blue (which is unnecessary), by only running the disk maybe 30 seconds at a time before quenching. Here are the results after the first shrinking.

The process took patience. I continued the cycle of shrinking and quenching, shrinking and quenching. 30-seconds on the disk, and then quench. After thirty minutes of this process, here were the results.

Then I continued the shrinking and quenching. After fifteen more minutes, I could tell I was making progress.

Finally, after sixty minutes of shrinking I could tell the improvements I was getting were diminished.

So I put down the shrinking disk and welded up the holes in the door. I used my 4 1/2″ angle grinder and some cut-off wheels to grind the welds smooth.

Then I cleaned off the whole area and treated it with some Metal Prep. There are certainly some low spots remaining, which I will fill with solder, but in general the low spots are much smaller and less deep. And perhaps more importantly, the metal is no longer stretched inward and won’t “oilcan” in and out when you press on it.

Driver’s Side Door Metal Repair

This morning I repaired a crack in the driver’s side door that had been caused by either the stress of the window pillar pressing outwards or the side-view mirror. In either case there was a crack in the metal that ran across the top of the door about three inches and then down the door another inch or so. I cleaned down to bare metal using a 3m Clean Strip disk prior to any welding.

I used a spring clamp to pull the metal together where it had cracked apart and placed one small spot weld at the corner of the crack to tack it back together tight. Then I placed several more spots across the top of the crack.

Then I ran spot welds downward and across until the entire crack had been mended. I went slowly and used only very short pulls of the trigger in order to keep the tacks small.

Then I used my 4 1/2″ angle grinder with stacked cutoff wheels in it to grind the profile of the spot welds flush. When the welds got close I switched from using the edge of the wheels to using the face in order to flatten them very close to the oringal metal.

The finished repair was barely noticeable and will require a minimal amount of filler.

Hood Repairs

This afternoon I spent some time doing some metal repairs on the hood.

The first order of business was to repair the holes that had been made in the upper corners of the hood to accept the hoodpins, which are history. Each side had one large hole for the pin itself and four smaller screw holes to which the circular pin plate was attached. I began by cleaning the metal bare using a metal stripping disk in my drill.

First I welded the four smaller screw holes, then the larger center hole. I used .023″ solid core wire and Argon/CO2 shielding gas.

Then I ground down the welds using a series of three cutoff wheels mounted in my 4 1/2″ grinder.

On the lip of the hood there had been a considerable amount of body filler used to straighten the front. After removing it the lip was a bit wobbly on the driver’s side front, where there had clearly been some collision damage. In fact, the area had been brazed in order to make it more solid. Here is the area before and after I cleaned the metal with an abrasive disk.

So I took the liberty of welding the cracked metal, which made it very solid again. I straightened out the weld beads using the cutoff wheels.

Engine Bay Sheetmetal Repairs

This morning I continued with welding sheetmetal repairs in the engine bay.

Before I did that I actually noticed a very small second hole in the driver’s side floorboard. Yesterday I welded shut one hole that measured maybe 1/4″ in diameter. This second hole was about half as large and located over by the door sill. I welded it shut with just a few short bursts from the MIG.

Then I used the Dremmel with the small cutoff wheels to grind off each weld flush to the floorboard.

In the engine bay, on the passenger’s side of the car, there were several holes where non-original accessories, for example the electrical fuel pump, had been mounted. Since I’m taking the engine bay back to stock configuration, I needed to repair any of these holes. Here are a couple of pictures of the holes toward the front and also two up higher in the engine bay.

Prior to any welding I removed any surface dirt and/or rust by cleaning around each hole using a 3M Clean & Strip Disk.

Then I welded up the holes using .023″ welding wire and Argon/CO2 gas. The lower rails of the engine bay were made of thicker sheetmetal, but on the sides I tried to back up the metal with some solid steel plate in order to diffuse the heat and prevent melting through.

Here is the finished result before I started grinding the welds.

First I began grinding off the proud welding metal using two cutoff disks mounted into my Dremmel.

Then I decided to mount three cutoff wheels in my 4 1/2″ angle grinder and use the edge of it to try to further smooth out the welds. This worked very well and provided a much broader footprint for flattening the welded areas to the surrounding sheetmetal.

On the firewall, in the niche where the brake master cylinder resides, there was a crack in the firewall. From what I’ve heard this is fairly typical and caused by the force of stepping on the brakes; the sheetmetal on the firewall eventually fatigues and can crack. In addition to repairing this I plan to install a firewall brace that has been invented to shore up this mounting point and therefore remove any slop in the brake pedal motion. Before beginning the repair I cleaned the area with a wire brush, on both sides of the firewall.

Then I re-aligned the sides of the metal where it had split by tapping on it with a body hammer.

Then I welded the two cracked sections back together.

And then I ground down the weld flush with the sheetmetal.

When I bought the car it had hoodpins, which are not original to the roadster. My intention has been to remove them. I removed the pins themselves and then I wanted to seal the holes they had been mounted to. I began by trying to raise the metal around the holes, which had been bent downwards to install the pins. I just used a heavy hammer to pound upwards from inside the cabin; no need to be delicate as I plan to fill the dents later. The main reason to try to roughly straighten the metal was to minimize the amount of filler required later. Here are the holes where the hoodpins had been.

So I just welded over the holes. Later I plan to fill the indentations so eventually there will be no evidence that the hoodpins had ever been installed.

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.