3 months since I actually did anything for the MR….for shame, for shame.
If you don’t want to read through all the text just scroll down to the bottom for the video.
Vacations, work, life, crap and the like are proving capable to hamper my progress. But not enough to completely exterminate the guerilla side of my life that is the MR2 restoration, tirelessly fighting to squeeze into the tiny crevasses that appear when life’s obligations and responsibilities doze off for a brief moment. Seems that what I wrote in my refusal of reality post was nonsense. I can refuse the reality all I want, it will still happen. The car is still sitting pretty with the engine out. The time when I could start the engine and move, it now seems like a dream.
To be honest, the real reason why it took me three months to post MR2 related progress was that I got obsessed with soda blasting. I saw a video of a guy soda blasting a bunch of car parts really effectively and I got mesmerized. I tried to clean my transmission case a few days before that and after hours of scrubbing and application of different chemicals I managed to clean like 2% of the transmission. And then I saw a transmission cleaned in like 3 minutes in that soda blasting videa. It looked brand new. I wanted that! I am not putting back that grimy disgusting thing back into the car. I decided I was going to soda blast it.
What is soda blasting?
When you first look at it, soda blasting doesn’t seem much different from sand blasting, but it is. It looks the same but doesn’t work the same. Sand blasting is an abrasive media blasting. Soda blasting works without damaging the underlying metal. It uses the explosive force of the tiny soda particles as they shatter on impact to knock the dirt, grease, paint etc. off the surface. (I am quoting garage night.tv on this one).
Why soda blasting and not sand blasting?
Soda doesn’t harm the environment. Soda will not damage bearings and moving parts because it is easily dissolved. Soda will not warp metal panels because it doesn’t generate heat. Soda will remove paint and all sorts of dirt. Soda will not damage rubber, glass, chrome, etc. Unfortunately it won’t remove rust.
All of this made it perfect for cleaning my transmission case as well as my engine head, engine block and a whole assortment of other parts like suspension bits, engine components, etc.
The pursuit begins
So, I began my pursuit of soda blasting in the form of a rather long streak of trial and error operations. I already had a compressor. It was a 2 HP, 116 psi, 24 liter (6 gallon) compressor. It allegedly delivered a cfm of 8.1 (230 l/min).
I started out with the cheapest method that required me to purchase nothing other than some plastic hose. This is the method you can see everywhere around the internet, repeated by many diy enthusiasts. The original source is this: http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/
So, I put together something similar using my own air blower gun and plastic hose. The results were pitiful. My compressor ran out of air after 2-3 seconds and I could clean almost nothing. I quickly realized I needed to replace the compressor.
A hunt for a larger compressor began. I found a used 26 gallon, 130 psi, 3 HP, 2 cylinder, belt driven compressor and managed to trade in my small one for it. It was time to re-test the air blower gun and hose method. It actually worked this time…..well kinda. It was flimsy, went through soda extremely fast and the surface it blasted was very tiny. Doing anything bigger than small parts would require a truck load of soda.
So, I decided it was time to replace the gun. The first thing I bought was a cheap siphon fed sandblasting gun. It was even more useless than the air blower and hose. After some research I realized I needed a gravity fed gun. Why? Because they need less cfm (air flow) for the same results. Siphon guns waste precious air on siphoning in the blast media.
So I settled for a far more expensive gravity fed gun. Gravity guns have two additional benefits. 1. You can adjust the amount of blast media coming in, which means you blast just air when you need it, which is very useful. 2. There is no flimsy hose you have to worry about keeping in the soda bucket or box. Just refill the gun container when you run out.
Finally, I got the desired results.
Here is my setup:
Compressor: 26 gallon, 130 psi, 3 HP, two cylinder, belt driven compressor
Gun: Gravity fed sandblasting gun. Anything professional or semi-professional will work
Blasting media: Sodium bicarbonate. I buy what I find in stores. No particular brand or anything.
Watch the video to see the setup in action.