While I have all the interior out I figured I would do a little seam welding on the car. Seam welding (one continuous weld) or stitch welding (welding for an inch then skipping an inch) helps strengthen the car. There are a few weak spots where the car flexes due to the crappy spot welding that Mazda used. I'm not going to go crazy and re-weld every seam in the car but there are a few places where I would like to concentrate my efforts.



The first place I would like to do is around the door frame:



A good example of how the metal is sandwiched together and spot welded is the corner of the door jam:



A closer look:



This looks like a good place to start:



I used my angle grinder to take off the paint and to trim the metal down a bit so the interior bits will go back on even after extra metal is added to the top:



First weld (don't laugh - I'm trying to get my settings right):



Now we are getting somewhere:



The second area I wanted to look at was the back corners of the floor pan:



Before:



More before:



I used a Harbor Freight angle grinder with a wire brush attachment to strip off the paint. I tried using an angle grinder disc but it just couldn't get into the corners well enough to strip the paint and rubber seam sealant:



Stripping off the paint:



More stripping off the paint:



All welded up and the tops of the weld ground down (makes it look uglier than what it really is):



More welded up:



I decided that this would be the last phase of the seam welding project. The remaining seams (see the bottom of this page) were either too hard to get to or too hard to cover up once I put ugly welds on them:



The first thing I had to do was remove the front bumper and the fenders. I actually didn't need to remove the bumper but I figured it was going to get ruined or get in the way later on during the engine swap so I decided to go ahead and remove it now:



When I purchased the car the bottom and wheel wells were covered with some really hard clay. This has made all the jobs I've done under the car and around the wheels 10X harder. The mud-dobber type shapes in the wheel wells had to be smacked with a hammer to remove them:



All of this came from inside/under the fender. This is why you don't store your Miata outside or drive it in the mud:



What is the torch and the screwdriver for?



Parts of the fender are held on with small plastic screw-like fasteners. You always strip out the top so I figured out a method for reforming the stripped part of the head. It doesn't look like it here but this ended up working really well:



After both fenders were off I cleaned up all the clay that fell out of them and that I knocked out of the wheel wells. This is three dust pans full:



This is what I pulled off:



It took me around 2.5 hours to get to this point):



Before:



More before:



There were a few places like this channel that were going to be pretty hard to weld:



You can see how deep the channel is:



I removed that channel with an angle grinder. I'm wondering if I ended up making it weaker by doing this. I'm sure the weld is going to strengthen it again but is it actually stronger than before?:



Done:



More done:



As promised above, here are the remained seam welds that I am not going to tackle: