Hood Body Filler Work

This afternoon I did some work applying body filler to the hood to smooth out the body solder repairs I’d already done. I’m finding that it is beyond my abilities to get most of the solder repairs perfectly smooth without applying some sandable filler to finish off the repairs. Also, on one particular dent on the hood the metal had been ground thin, and when I applied heat to try to solder that area the metal simply buckled. Areas like this are not good candidates for solder repairs, so I used filler exclusively on that shallow dent.

My filler of choice is Evercoat Metal 2 Metal, which is a high-quality filler that has small particles of metal in it that give it a metal appearance. It is plastic filler, make no mistake, but has a metallic appearance. In my limited experience using it I have found it to be a very high quality filler and easy to apply, work, and sand. I bought the filler from Eastwood; buying from a place that turns over a lot of product means you will get relatively fresh stock, whereas a can that has been on the shelf for a long time can be a little less flexible.

The first thing I did was to wipe down all of the areas I was applying filler with paper towels and acetone to clean the metal and remove any grease. Next I cracked open the can of filler.

I used a plastic mixing board and just plastic applicators available at Walmart. As per the instructions on the can I used about a golfball-sized dollop of filler and applied 10-12 drops of the hardener.

With the hardener added I mixed it into the filler on the board.

Wearing rubber gloves, because filler will definitely stick to your skin, I swiped on two stripes of filler over the larger hood dent. By experience I have learned that it is much better to work the filler less than more, because continually going over it makes the coat less smooth, not more smooth. The Metal 2 Metal has decent working time, but is most pliable when it first goes on.

I also skimmed over the weld and solder repairs of the hoodpin holes, as well as the smaller solder-repaired dent on the opposite side of the hood.

And I attacked the front hood lip, where I had done a lot of soldering. I applied a thin coat of filler to fill the remaining dents and to blend the damaged area into the other side of the lip.

Body Solder Repair, Hoodpins

The last thing I did today was to apply some boldy solder into the remaining voids in the body where the hoodpins had been mounted using the same process I’d used on the apron.

After applying the solder I grinded and sanded the area to finish the repair.

Front Apron Body Solder Work

This afternoon I spent about an hour working on repairing the front apron, which had evidence of collision damage and a previous repair. I previously welded up the holes that had been used to straighten the dents before filler (but had never been filled). So the first step was to grind down those welds as flush as possible. I used my angle grinder with three metal cut-off wheels stacked up to widen the profile. This makes it easier to cut using the edge of the wheels.

After I was finished they welds where fairly flush. I used my body hammer to straighten the apron a bit by tapping the inside and holding my dolly on the face of the apron.

Nevertheless the metal was fairly wrinkled after I tried to knock the dents outward, even proud of where they should be.

So I used my shrinking disk to try to shink the metal which had first been stretched inward when the dents occurred, then stretched outward when the previous owner pulled the dents and finally when I tapped them outward with my hammer. I applied the 9″ shrinking disk, mounted in my large grinder to the surface of the apron to build up friction and heat localized to the high spots, then quenched the area using water to shrink those same spots. I repeated this many times and began to see some progress.

After spending several minutes heating and quenching I saw some progress but realized I would still need some filler to get the apron smooth again. So I cleaned the area using a 3M Clean N Strip wheel mounted in my drill.

Next I painted on a coat of the tinning compound that helps the lead-free body solder bond to the steel. I used my propane torch to heat the tin until it bubbled brown.

Once the tin turned bright silver I used a clean cloth to wipe away the brown impurities.

With the tin applied I quickly cleaned it using some hot water and once it dried I wiped again with acetone. Then I applied the solder to the apron.

After applying enough solder to stand proud of the apron I used my cut-off wheel again with the same three-disk set-up to start grinding away the surplus solder.

After grinding for about fifteen minutes to get the basic shape I switched over to my random orbital sander with a 60-grit sanding disk. One of the nice aspects of the lead-free solder is it is safe to sand, unlike lead.

The sanding blended the solder into the surrounding steel and made it much smoother. Clearly it still is not perfect, but structurally the area was set and would only require a thin coat of filler to be smooth.

Hood Body Solder Work

I spent most of the afternoon applying lead-free body solder to the damaged areas of the hood.

When I bought the car it had been fitted with hoodpins, which are not original to the roadster. Previously I removed the pins from the body and welded closed the holes in the hood. Today I got started by cleaning up those patch areas using a 3M Clean ‘N Strip wheel in my drill.

It was important to clean the area because the Metal Prep I used to inhibit rust formation leaves a thin protective covering over the bare metal, a coating I wanted to remove before applying body solder.

There were some other areas of the hood that would also need soldering. The hood had clearly suffered from a collision to the front right of the roadster and I had previously welded up a crack along the edge of the hood lip. But the lip itself remained a bit wavy. Here is that area before and after I cleaned it.

There was also a small dent on the passenger side toward the top of the hood.

And a larger dent on the other side of the hood.

After cleaning the metal with the wheel, I wiped all of the areas with acetone to remove any dirt or grease on the surface.

The body solder will not bond directly to steel, so I needed to apply a tinning compound that bonds to the steel and then bonds to the solder. I brushed on the tin generously.

Next I heated the tinning compound using my Propane torch and wiped it using a clean shop towel to remove any impurities that burned off.

Here is a shot after the tin was applied. Afterwards I washed the area using clean water to remove any acid residue that the tin can leave. Skipping this step could lead to rust later.

Then I applied the solder using my propane torch. I had to move fairly quickly, and with the hot solder in one hand and on the verge of running off the hood and the propane torch in my other hand it was difficult to take pictures. I got one about halfway through, and another after I judged I had applied enough. My philosophy with the body solder has become to apply more than enough and grind it back as close to smooth as possible, rather than try to work it with a paddle, which I find is very difficult to do.

I followed the same steps of cleaning, tinning, cleaning, and applying solder to the hood pin areas.

And to the small and large dents in the hood.

Next I finished working the repair on the hood pins. I started to shape the solder roughly level using my angle grinder with three stacked cut-off wheels, which creates a broader flat edge to cut away the metal.

Using the grinder I was able to get the profile of the repair fairly flat.

Then I finished smoothing the repair using some 120-grit sandpaper and a sanding block. The result was not perfect, but close. This area will require only a thin coat of body filler to be undetectable under paint.

Here is the profile.

The larger dent in the hood deflected with heat, probably because the sheet metal was thinned from grinding when originally repaired with body filler. So solder was not very useful in that area, and I will use body filler to address that area later. But the smaller dent took the solder well and the final repair was very smooth.

I finished the day grinding the solder as smooth as I could on the hood lip.

Rear Fender Patch Cut-outs

The first thing I did this afternoon was cut-out some steel patches for the rusted holes in the rear fender wheel-well lips. I roughly measured the size of the three patches I’d need and cut them out of 18-gauge steel using a metal cut-off wheel in my angle grinder. I shaped each as a rectangle, and rounded the corners because welding sharp corners can be a challenge. I find it easier to weld the radius of a rounded corner.

Here is a picture of the rusted hole in the right rear fender lip that I intended to patch, and one showing that my patch was large enough to do the job.

I traced out the perimeter of the patch on the fender using a black marker.

Later I will cut-out the bad sheetmetal and weld in the patches.

Right Rear Fender Dent Repairs

This afternoon I spent about three hours working on some dents and dings in the right rear fender. Behind the right rear wheel was a crease-like dent running up the fender, maybe five inches long. I went over the area with a black marker to isolate the low area–the marker essentially acted as a guide coat.

After the whole area was colored black I used a sanding block to sand it off again.

Then the low spot of the dent was clearly apparent as the dark area where the marker remained.

I used a dolly and a slapper, tools that came in a set I bought from Harborfreight. I placed the dolly inside the trunk up against the low spot in the fender.

Then I used the slapper on the outside of the dent to actually strike the dolly through the low spot in the metal. It is counter intuitive, but the slapping on the outside actually causes the dolly to raise the metal upward upon impact. I used the slapper rather than a body hammer because it has a much broader face, making it easier to strike the dolly. The important thing was to position the dolly in the right spot. Every time I connected, a bit of the black marker would show the impact, allowing me to locate my blows strictly within the low spot of the dent.

After working for about thirty minutes with the dolly the dent was beginning to rise, so I moved to my shrinking disk to try to level out the surface. When the dent occurred the metal stretched both downward at the crease of the dent but also upward at the edges of the crease. The shrinking disk would enable me to lower those raised areas on either side of the dent. I quenched the heated metal with a spray bottle containing water.

I repeated the shrinking and quenching several times.

Here is a look at the dent from above, showing that it had come back into alignment somewhat.

Next I repeated the process with the black marker and sanding, which revealed that the crease had become decidedly less pronounced and that the surface was more uniform.

Then I went back to work with the shrinking disk until I was satisfied that the metal was very close to its original shape.

On the same rear fender, up on the ridge of the body, there was a small dent that was very obvious because of its placement on the body line. I used a Clean & Strip wheel to clean the metal in preparation for applying tinning compound to repair the area with body solder.

I brushed on a thick coat of the tin.

And I heated the tin with my propane torch, wiping away the impurities and spreading the tin uniformly across the surface.

After the tin was applied I began heating and applying the body solder.

I tried a new method this time, different from the way I applied body solder to the passenger-side door. Rather than try to form the repair with the clumsy paddle, I just applied an excess amount of solder so that even the lower edges of the repair were above the original metal, reasoning that I could remove the excess and get a smooth repair.

In my 4 1/2″ angle grinder I mounted three cut-off wheels on top of one another. This gave me a thicker profile so I could use the edge of the wheels to grind away the solder. I went to work grinding the solder repair and the grinder worked very well. The bottom cut-off wheel actually wore away, leaving the three wheel edges at an angle so I could use the edges of the three wheels to smooth the edges of the repair.

After several minutes of careful grinding the area came roughly into shape.

Then I hand-sanded with some 120-grit sandpaper and the area became very smooth and into profile with the body.

And here is a look at the repair from the rear.

There was also a small, quarter-sized round ding in the same rear fender just above the larger dent, located above the side moulding. Below, left is a picture of it after I used the black marker to show its low spot, and to the right is a picture after I cleaned the area with a Clean & Strip wheel.

Using the same methods I used on the other dent, I applied the tinning compound, washed the area, and applied body solder.

And after grinding and sanding the ding was back in good shape.

And I followed the same procedure to solder the larger dent down below. I stripped the metal, then wiped it with acetone to remove grease and/or marker that remained.

Then I applied the tinning compound, followed by the solder.

Here is the solder applied over the crease, proud of the surface, and after I did some grinding and sanding of the area.

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.