Saturday, August 20, 2011

Clock face brass completed

I got the silkscreened brass back from James at Preston Screen Printing this morning. He did a great job with it.

I was able to work quite a bit more on the clock today. I need to clear laquer the brass face to keep it from tarnishing, but I have to do it when it's between 50 and 90 degrees. Our string of 100+ degree days isn't helping on that front. I got a lot done on the frame for the face. The original grandfather clock frame left a big gap around the brass face and looked rather bad, so I'm constructing an oak frame that will fill the gap. This will make the face a permanent fixture of the clock, so the mechanism will have to be accessed from the back instead of the front door of the clock. It's gluing this evening, so hopefully tomorrow I'll be able to get the router out and put a decorative finish to the face frame and start to get it installed.

Tuesday, August 9, 2011

Clock face to be silkscreened

I just dropped off the brass for the clock face and the design to James at Preston Screen Printing. His rate is very reasonable. When I get the piece back in a few days I'll post results pictures.

Sunday, August 7, 2011

Update 8/7, Part 2

Aside from the clock face itself, I started work on the hands. I wanted each hand to be slightly different and hold a photo of each family member. I haven't figured out the photo mounting mechanism yet. I want the photos to be fairly easy to replace since I have young children and their appearance is likely to change over the years (imagine that). I got a tril copy of AutoCAD and drew up the five hands.

I have a couple thicknesses of sheet steel I want to use for these, but I'm not sure yet how well I can cut and drill these out. I think between my drill press and nibbler that I should be able to do pretty well, but I'll have to try out a couple first.

Update 8/7, Part 1

I was able to work a bit on the clock the past couple of weekends. First, an update on the clock face:

I found that ironing the toner to a clean, shiny piece of brass was a non-starter. I found the best technique to be scrubbing the brass with a green Scotch-Brite pad in perpendicular directions improved the toner adhesion quite a bit. The second was to thoroughly clean it with acetone to remove any oils or other dirt that may have accumulated. Regular alcohol was not sufficient. After I did both of these I got what I hoped would be two good sample tries. The first was using laser printed on inkjet photo paper like many online sites recommend, and the second was a glossy laser paper. I liked the second better because I was able to get it printed at tabloid size, whereas the inkjet photo paper was letter size only. I should have grabbed some shots of the two samples. The inkjet paper left only toner behind and it was nice and shiny, the glossy laser paper left quite a bit of paper residue behind. In either case it looked like the transfer was pretty good, so I moved onto the galvanic etching.

I took a bucket of water and dissolved about 2 cups or so of the root killer (Copper Sulfate). It left the water a bright blue color as many other's attempts did. I taped the positive lead from my battery charger to the back of the plate to be etched and submerged it all the way to the bottom. I suspended a scrap piece of brass about 4" above it with some bent coat hanger. The battery charger was set on the 12V/10A setting and I could tell something was happening because the charging indicator was about 1/2 way between "doing nothing" and "full out." Within a couple minutes the scrap plate was starting to turn black on the underside. Here's a pic of the setup:

The results were impressive. I did the first one for about 20-25 minutes to get a nice etch. I think it took so long because I didn't mask off the edges and it really had to remove a lot of material. The second went about 15 minutes and got a real good etch. This method of etching really does work, but the toner didn't stick as well as I would like and left a lot of pitting and not a very clean look. I would be ok with a little bit of pitting -- it would add to the antique look of the piece, but this was overkill. See my sample results 1 and 2:

At this point I'm tired of wasting time trying to find the "perfect" paper to do a toner transfer and etch. I'm investigating now having the image screen printed to the brass in black ink. I'll probably laquer over the paint to help protect it.