A friend of mine has a black 3rd generation RX7 that is stunningly beautiful. Over the years it has acquired an epic list of modifications, and made ludicrous amounts of horsepower with its single turbo conversion. There has always been one modification under the hood that has never been quite right though… the battery box.
See, many years ago, he upgraded his battery to a smaller unit to save space and weight. Naturally, he also got the special sized smaller battery box to hold it. The problem was that the battery box didn’t have a strap to hold the battery in, nor did it have any brackets to even add one! He contacted the company that made it, and they told him to put some silicone or RTV in the bottom of the battery box and drop the battery down on top of it. When it dried, it would hold the battery in place. Nice solution. That idea is great until you need to replace the battery, which he did this past week.
battling separating the battery from the box, he handed the box to me and asked me to make a new strap for it. Since I am still new to aluminum TIG welding, I figured it would be a great reason to practice my welding. The problem was that I didn’t know which way the battery was supposed to sit in the box, and since the battery terminals were on one side I needed a way to have it work in both directions. I drew out a diagram or two, cut my name out of a piece of scrap steel, and then sliced, diced, and drilled aluminum until my heart was content.
Aluminum in a finicky metal that doesn’t like to bend in the same spot more than once (lesson learned), and doesn’t enjoy being welded by a novice (ehem…). If the metal isn’t 1 million percent free of any contaminants, your welds end up looking like you sprinkled Oreo cookies in them, which is not typically desired. I have found that a stainless steel wire brush and Scotch Brite pads typically work fairly well for this. You just need to make you don’t put your greasy hands all over it once it is spotless or you get to start over.
TIG welding is still fairly new to me, and was somewhat ugly at first, but the more I welded the better I got. There are a few things that seem to make a HUGE difference for me when TIG’ing. The first is obviously clean metal, you absolutely must have clean metal. If you don’t, don’t even bother trying to weld aluminum, it won’t work. The second necessity is proper torch angle. I think that most people that know what they are doing recommend a 35 degree torch angle, but if you are a beginner like myself, just try different angles and watch how good and bad it can get. 35 degrees seems to be pretty close to the magic number. The 3rd and final thing is keeping your filler rod away from the heat, and when the aluminum makes a horseshoe shape, add filler. The aluminum filler rod melts easily when you hit it with 75 amps of hell fire, so back it up when you don’t want it to be liquified. Practicing your filler rod movement while you aren’t welding makes you feel like an idiot, but I think it really helps. Once you get the hang of adding the filler and controlling the aluminum weld puddle, TIG welding is very rewarding. Your final product looks beautiful, and you can brag about it to your friends, family, and the entire internet, like this.
As for the battery box: Here is the final result. As you can see, it isn’t polished, it isn’t glued in, but it does have a fancy new strap that can be flipped around to the other side juuuuust in case I guessed wrong. ;)