How about some oxyalic acid tips?
Things like what ratio of acid crystals to water, soak times, parts prep, and so on. The instructions on the container are for its intended use, and as such no use to us. If we could compile some basic instructions, I think a lot of folks would find it useful.
I've only been playing with OA for a couple months and am no expert so these suggestions shouldn't be written in stone. YMMV
De-grease parts before soaking.
Warm water speeds up the process.
1 teaspoon to a small bowl = 4 to 6 hours soak time.
1/4 cup to a 12" x 18" tub 4 inches deep = overnight
1/2 cup to a 18" x 36" container (under bed linen container) = 2 days and may require another 1/4 cup if the action seems to be slow going.
Generally, the larger the container, the less concentration of OA used (for economy purposes), thus the longer soaking times.
Use a white 3M pad to loosen the scale from time to time. I haven't been able to find white 3M's where I live so use a blue scratchless Scotchbrite pad instead.
Rinse off parts and then soak them in a water and baking soda bath(or use a BP paste) to stop the oxidation when finished. Blow dry, then use framesaver or Amsoil Heavy Duty Metal Protector inside frames and bars, and polish outsides to prevent future corrosion.
I'll add more tips to this post as I think of them. Off to work now...
Last edited by McDave; 02-02-07 at 07:42 AM.
One thing I have noticed is that if you have zinc-coated things like bolt heads or derailler hangers the Oxalic acid can dull the previously shiny surface. Not sure if this is just a dull coating that can be removed with super fine sandpaper or if it is more permanent.
I don't think it is a dull coating, I believe the acid dissolves zinc and cad platings. If you watch the process, you will see bubbles coming off the zinc and cad plating.
Originally Posted by evwxxx
In the hardware store, by the oven cleaner is a brass brush the size of a oversized toothbrush. It costs about $1.50 and won't scratch your chrome. I believe its intended use is to scrub your enamel coated oven without scratching it but it works wonders on that stubborn rust.
Stay away from the brown oxyalic acid .
Is that like yellow snow?