How long is it take to do that last bunch? If you're doing a few bolts at a time I'm thinking it will get a bit long in the tooth after awhile?
Azr,
The actual plating process only takes about 15 to 30 minutes, depending on the thickness of plating you wish to have on the part. I have been plating my parts for approximately 20min. In the previous photos, I did all of the small parts in one batch and the axle itself in one batch. So, if you add 10min of prep time to teach batch, that's approximately 30min per go-around. I can plate a batch of parts that requires a maximum cumulative amperage of 5A, with .14A per square inch of surface area. However, I don't like to run my rectifier at full capacity, so 4A is the most I like to go.
The plating isn't that difficult - its the prep work that requires attention, otherwise, your finish will not come out looking pretty. Thus far, I have settled on the following process and it is working well:
ITEMS OF IMPORTANCE:
Parts must be free of heavy grease and oil - if not, use mineral spirits, brake cleaner, a parts washer, etc to perform an initial degrease
Use Caswell's online tools to calculate the surface area and amperage required for each part BEFORE going through the prep stage
1. Immerse part in a 50/50 mixture of pool-grade muriatic acid and distilled water to dissolve existing zinc plating and rust
2. Once parts stop fizzing, remove and IMMEDIATELY dip in a mixture of baking soda and tap water - this is essential to neutralize any remaining acid on the part, otherwise, it will flash rust very quickly.
3. Rinse parts in hot tap water
4. Buff parts with wire wheel until shiny
5. Scrub parts with a toothbrush in a 50/50 micture of either simple green/water or purple power/water to remove any residual oils/grease. WEAR GLOVES and DO NOT touch the part with your bare hands
6. Rinse the part in hot tap water
7. Rinse the part with distilled water
8. Hang the part on copper wire from a copper bar and put it in the bath
9. Attach the positive lead to the zinc anodes and negative lead to the copper bar from which the part hangs
10. Turn on your rectifier and adjust the amperage
11. Set your timer for 15 to 30 min
12. When the time is up, shut off the power supply and remove the parts
13. Rinse parts in distilled water over your "plating rinse" bucket - this water can then be re-added to your plating tank when the level diminishes
14. Dip parts in a 1.5% sulfuric acid/distilled water solution for 3 to 4 seconds - this will brighten the part significantly and eliminate the need for buffing
15. Rinse the part in distilled water
16. Dip the part in blue chromate for 15 to 30 seconds, depending on depth of color desired
17. Let parts air dry for 4hrs minimum, overnight preferred.
Some of the things that are also important are: keeping the bath around 80 to 95 degrees using an aquarium heater (some people don't bother and still have good results). Also, agitating the solution during plating using a miniature aquarium pump is key to avoiding hydrogen spots on your pieces.
Long story short, I had some difficulty with my parts coming out of the bath slightly dull, even with the appropriate amount of brightener added to the plating bath - this dullness was easily buffed away with some 000 steel wool. However, I wanted to eliminate the buffing step. After a few phone calls to Caswell and picking the brain of the tech support guy, he suggested the 1 to 1.5% sulfuric acid "brightening dip" before the chromate step. This works amazingly well, as it really clears up the zinc. The nitric acid in the chromate will brighten up the part the rest of the way. Although I will maintain adding brightener to the plating bath every 3 to 4 plating sessions, the sulfuric dip makes using brightener less critical.
Does this help?
PS: I forgot to mention - when you are done plating for the day, remove your anodes from the bath and rinse them with distilled water and then let them dry. If you leave the anodes in the bath overnight or for several days (like I did), they can oxidize and impart a dirty look to your parts. If this happens, take them out, scrub them down with a scotch-brite pad in some degreaser, and then rinse them with distilled. I soda-blasted mine to clean them off. Then, Remove your heater and pump, rinse them with distilled, and then cover the bucket - buckets with airtight lids are very helpful in this situation.
IMG_1224 by Anthony Monteleone, on Flickr
IMG_1225 by Anthony Monteleone, on Flickr
IMG_1226 by Anthony Monteleone, on Flickr
IMG_1227 by Anthony Monteleone, on Flickr
IMG_1228 by Anthony Monteleone, on Flickr
IMG_1229 by Anthony Monteleone, on Flickr
