Friday, July 13, 2012

A Tom Sawyer Day

Being sore from scraping wallpaper the previous two days, decided to follow the lead of Tom Sawyer and let Jan’s nephew scrape away while I had a little fun working on RV-12 parts.

This was the second session of using Sanchem CC-6100 corrosion protection and already I can see this is going to be a grueling task.  For the first round I was using Naphtha (Coleman fluid) to remove oils then washing all the parts in a Dawn & water solution before using the Sanchem "C" cleaning and activating solution ... then on to the CC-6100 solution. I decided I could skip the Dawn & water wash for two reasons.

First – most of the parts have had the blue protective film recently pealed off and I’m using Acetone now as a part cleaner. The Acetone appears to leave no residue and cleans the parts very well. Second – the Sanchem cleaning and activating solution appears to have a cleaning agent in it because it produces light suds while rubbing the parts with a Scotch-brite pad soaked in the solution .... ( and verifying a break free surface).

Even with the deletion of the Dawn wash, it still takes quite a bit of time per part. Figure about 5 to 8 minutes of scrubbing on the parts (more for longer pieces) followed buy a distilled water rinse then 3 minutes in the Sanchem CC-6100 solution followed by another distilled water rinse. So that is approximately 10 minutes per part, you don’t get a lot of production per hour.

Thinking mass production, I tried placing a handful of parts in a 1 gallon freezer bag and pouring in the CC-6100 solution. Sounded like a great idea … but in practice the parts would cling to one another and it produced poor results. I was able to place multiple parts together, but they must be kept separated for optimum results.

Below is a photo of the best constancy I have had thus far by using an Acetone wipe, skipping the Dawn wash, Sanchem part "C" cleaner with Scotchbrite until the part loses its sheen. Sanchem says the parts can go straight from the after cleaner distilled water rinse into the CC-6100 while still wet … However, I found that drying the parts first yielded much nicer results. If the parts were dry going into the CC-6100 solution there appeared to be a more even golden color after 3 minutes followed by the final distilled water rinse.
                                                    The finished cold conversion pieces have a golden hue …
                                                    the untreated pieces are the shiny aluminum ones.

For the longer pieces such as spars I decided to try placing the CC-6100 solution in the equivalent of Seal-A-Meal bags which are long continuous tubes. I used 8” bags which to my amazement worked out well. They are quite sturdy and because I rounded the corners on all the parts, there were no tears. I would lift one end, let the solution slosh to the other side then repeat the process occasionally flipping the bag over so all surfaces received an equal amount of the solution.
                                        Placing the long parts in a continuous Seal-A-Meal type bag worked out quite
                                       well and produced a far better result than brushing the solution on the longer parts.

Benefits of using a continuous bag is the bag can be rolled up for shorter pieces and less solution is necessary and then unrolled for longer pieces. All and all it worked out well and with little mess.