How to shave and metal finish your firewall with Empire Fabrication

Shaving or smoothing the bodywork on a custom car has been one of the most popular modifications since the beginning. Shaving door handles and trim or side marker holes are the most common things to shave on a project car, but close behind that is smoothing or shaving the firewall. Sean of Empire Fabrication has gotten REALLY good at shaving and smoothing cars. So much so that his finished projects require basically no body filler at all and can be primered and block sanded straight away. Sean recently took the time to snap some photos and give us the rundown on how he tackles a firewall shave project. The donor vehicle is a VW Eurovan that he has already drastically customized. So grab a drink, sit back, and watch how to do the job right with Empire Fabrication.

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1. The main sore thumb of this firewall are these five holes. First any paint, seam sealer, or rust have been cleaned up and the panel is wiped down with PRE Prep cleaner.

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2.Welding up each hole individually would put extra heat into the panel (causing extreme warpage) so the entire area was cut out to reduce the welding needed.

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3. The area traced out is then cut out using a set of aviation snips.

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4. Once the area is rough-cut a barrel sander on a pneumatic angle die grinder is used to round the corners of the opening for better heat distribution when welding.

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5. When shaving or patching sheet metal be sure your patch panel is the same gauge thickness metal as what’s on the car. Having the same gauge thickness means that you can more easily metal finish the panel in the end. The firewall on this van measured to be 20 gauge, so 20 gauge was used to fill the holes.

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6. A tight fitting patch panel is key when trying to TIG weld sheet metal, so a piece of metal a little larger than the hole being patched was held behind the hole we’re filling so the exact size of the opening could be traced onto the patch. Blue layout fluid or machinist dye was applied to the panel so the scribed outline of the opening was easy to see. Finally the patch is carefully cut on the scribe line with aviation snips.

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7. A tight, precise fitting patch panel can be tightly fit into the opening and clamped in place using a set of locking welding C-Clamp Pliers. Then the TIG 200 was used with the mini torch to tack weld around the panel. Each tack weld is hammered flat and the panel is checked to make sure it’s still fitting correctly.

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8. Sean had the TIG welder set to approximately 35 Amps as he worked his way around the seam welding it up. Afterwards he checked to make sure there are no pinholes or spots that were missed when welding. Even at low amperage and quick welds you can see the panel has warped still. Don’t fear it CAN be fixed!

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9. Sean started by knocking any proud welds down with a sander and began hammering on-dolly, directly on the weld seam. This will flatten the welds out and also will begin to stretch the metal back out to reverse the shrinking that occurs when you weld sheet metal. He then applied another coat of machinist layout dye on the panel so he could sand the work area with 150 grit sandpaper to highlight the low areas in the panel.

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10. Any low areas around the welds require another round of more on-dolly hammering of the weld seam. Once all of the majorly low areas have been bumped up, the dye is sanded off with a DA sander so more dye can be applied to check the panel again.

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11. This time around a slapping spoon is used to hammer on-dolly to smooth any larger areas with numerous small imperfections. The slapping spoon covers a larger area and tends to level the small highs and lows that are close to each other.

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12. Finally a bullseye pick is used to pick up any areas with larger low spots. This tool allows precision hits on the low spots to quickly raise them level.

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13. Once the hammering, picking, and sanding portion looks pretty close, a DA sander was used again with 150 grit paper to sand out any small imperfections. As you can see the panel is now dead flat and there’s almost no trace of the repair from the front side. A poly or high-build primer and a round of block sanding would make this panel perfect and ready for paint!

Follow the Project Eurovan and all of Sean’s quality fabrication on his Instagram page HERE.

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14 thoughts on How to shave and metal finish your firewall with Empire Fabrication

  • Very impressive metal work, I have done a lot of mefabrication myself including shaving door handles and smoothing out firewalls so I know how much work it takes to do quality work like this, this man is one hell of a metal worker, serious props to the guy who did this

  • I’m 66 yrs old. Maybe one day I’ll do work like that. In the meantime, can you please give me his home address. I need to kidnap him and bring him to my house for my project. Coffee and bacon sandwiches are free.

  • Great job. Question, I have a firewall I am doing. Cannot get arm inside to do any hammer and dolly work. Afraid I am going to screw things up if I weld it. Any suggestions?

  • You could use bullseye picks to pick up the low areas or you can also resort to using a stud gun to pull out low areas. Alternatively you could have a helper hold a dolly as you hammer.

  • When is it appropriate or recommended to use a “lap panel repair”? A “Lap panel” developed from off set vise grip pliers.

  • I have a hole in a hood and need to have both sides look good. Would I used the same method to repair, just finish both sides for painting?

  • I would like to start think of new skill other interesting in fabrication with metal work for hot rods. I enjoyed to check on your instruction and show us how to do. Thank for appreciate it. I hope someday I will buy these fabrication equipment at Eastwood.

  • Is it required to TIG weld or could you MIG also. I liked the article but don’t like the idea of having another type of welder in my home shop.

  • This process requires hammering on the weld which isn’t advisable with MIG welds as they can be fragile and extremely hard. TIG welding or Gas welding are the two best types of welding to metal finish a panel completely like this article shows. The process can be done in a similar fashion but it is much more difficult and very very hard to get the weld seam completely gone AND completely smooth and straight like this.

  • Yes you would need to take the same steps to the backside of the panel, but it should be a lot easier/quicker if you have metal finished the outside and made sure it’s flat and back into shape. If the repair is pretty much flat/back into shape you should only really need to blend the weld seam in on the backside and do some minimal bumping.

  • I have been using ESAB’s Easy Grind .023 mig wire for sheet metal. I find that it isn’t very much harder than the parent metal and find no issues with grinding or even drilling through the weld. A harder weld will cause the drill bit to try to migrate away from the weld. The part number is ESB130TF43.

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