I’ve never been too interested in “tubbing” an engine bay. I don’t run big wheels up front so I don’t need the extra clearance. However, the factory metal was in pretty bad shape with a bunch of dents, rust and waviness. The way the engine room looks is a big deal to me so I thought cutting the problem area out and replacing making tubs would be the best solution. I knew it was going to be a giant pain in the ass, and I was right…

With the inner-fenders (or whatever the hell you call them) cut out, I made a cardboard mock-up of the tubs to get an idea of what I was in for, and how much steel I was going to need. My original plan was to make everything from scratch, including the arches. However, after looking at what other people had done I decided I liked the curve you get along the arch with trailer fenders.

I was going to order one online, but discovered Northern Tool keeps them in stock. The fender was less than $40 and I only needed one since I’d be cutting it in half. The biggest they had in stock was 10”. If I did this again I think I’d go with one 12” wide. The actual dimensions of the fender I used are 31.5” in length, 10” in width, and 13” in height.

The base plate went in first. I had a 16 gauge sheet left over from another project, which was enough for both sides. It was definitely overkill, and a pain in the butt to bend in my workbench mounted break. I definitely should have used either 20 or 22 gauge steel. This wasn’t the final shape of the base plates as all the excess material would get cut off after the arches and side panel were in and everything welded into place. I just didn’t want to end up short on material and having to go back and weld in plates to fill gaps.

The most annoying part of the whole process was getting the curve of the strut tower transferred to the fender. I’m sure there’s some professional fab-guy way of doing this, but the best I could come up with was a cardboard template. It ended up not being a great match so my actual cut in the fender had some big gaps, which I was able to weld up later on.

With the base place secured with a couple of tack welds, I started playing with the fender and trying to figure out exactly how I wanted it to sit. Once I had a good idea of where I wanted it I used a big sharpie to trace the position, because the fender would have to come back off to weld the side panel on.

I used some more cardboard to make a template for the fender side panel. Although I had enough 16 gauge left to make panels for both sides, I did the smart thing and picked up some 20 gauge from my local metal supply shop.

Jumping forward a few steps I had the side panel panel cut out and tack welded to the fender. I also made the outer wall out of 20 gauge and gave it a bit of a bend in the break just for looks. After moving and adjusting for what seemed like a couple of hours, I was finally satisfied with where everything sat and added spot welds to keep it all in place.

With the passenger side in place I decided to move onto the driver’s side. I was acutely concerned with making both sides match. Taking my skill level into account, I knew things weren’t going to look perfect, but I wanted them to at least match each other. To capture the curve at the strut tower accurately used some aluminum foil to make a “3D” template. Once I had the foil shaped I used a marker to trace the curve where the fender and strut tower met.

Once the foil template was cut out I simply flipped it over used the “mirrored” curve to mark the driver’s side fender for the cut. The technique worked pretty well and the fender lined up with the strut tower almost seamlessly. There were a couple of small gaps, but they were easy to fill in with the welder. Definitely much better than the passenger side.

Eventually I got all the panels cut and everything spot welded in. I ended up adjusting the tubs to line up more with the fender rails just so I could get as much clearance underneath as possible. Clearance that I don’t actually need…

At this point I got tired of taking pictures and just pushed through the task of grinding all the welds, filling all the seams and making everything smooth. It took hours of sanding and blending, and was definitely the most tedious aspect of the project and not something I want to ever do again. The worst part was sanding the corners smooth, but I eventually got everything to a “good enough” point and was ready to prime the bay.

Before I moved onto priming, I decided to just go ahead and spot weld the rest of the seams in the bay. I’ve read differing opinions on whether or not this does a damn thing for chassis stiffness, but it only took about 30 minutes and ended up looking pretty cool, so whatever…

Since most of the bay was down to bare metal I had to start with etching primer. I used Dupli-Color out of a spray can. Once I had a couple of coats on I got a good look at my work. It wasn’t perfect, and I immediately noticed all of my mistakes, but was happy with the way the fenders mirrored one another pretty well.

In addition to the etching primer, I used Dupli-Color spray cans for both the high-build primer and base coat. This is definitely not the route I’m going to take for the exterior, but I figured it would work out well enough for the engine room. The color I chose was Gunmetal Metallic. I considered a lighter gray or even silver, but I though the gunmetal would help hide some of the flaws. I went through 2 cans of primer and 5 cans of gunmetal to fully cover the bay in a couple of good coats..

The shot on the left is after high-build primer and the right is after a coat of the gunmetal. Unlike a 2-stage base shot from a gun, which dries flat and doesn’t have any shine until you spray clear, the Dupli-Color Perfect Match dried with a shine like a single-stage enamel. I did my research before hand (i.e. watched a couple Youtube videos) and already knew I wouldn’t have a problem spraying my good 2K clear over it with my HVLP gun.

The weather had been nice so I rolled the S13 out into my driveway to clear the bay. I primed and based it in my garage with fans blowing and the garage doors open, but clear coat is a different beast and gets everywhere. Plus I really wanted to see everything clearly while laying it down (no pun intended). The data sheet for the Finish-1 clear I use, which is mid-grade, calls for two medium coats. Instead, I always lay down a dust coat, two medium coats and then a final heavy coat. On the final coat I lay it down as thick as I can while avoiding runs. This is because I don’t have a high-end gun and I know I’m going to be wet-sanding and buffing out plenty of imperfections.

I ended up with a couple of runs, bugs and stray hairs in the clear, but I should be able to take care of that when I wet-sand and buff. You’ll notice from this angle that I didn’t blend the sides of the trailer fenders in with the side panels. I thought about it, and I’ve seen others do it, but I thought it looked cool with it blended on the top where it meets the strut tower and not on the sides.

Once the clear-coat had dried for about an hour I moved the S13 back into the garage. I wanted to get a good look at the finish under all the new LED lights I installed. Definitely some orange peel issues, air bubbles and a couple small runs, but nothing that can’t be fixed easily. Over the next week or so I’m going to wet-sand and buff it the best I can, which will wrap up the engine room. Overall the whole process has taken a couple months, and it’s not one I care to repeat any time soon. I’m glad I did it, and from this point on everything is going to seem like a breeze…