Prepping copper

[botticelli1972]

For $400 you could by numerous vintage plates that have been wiped or otherwise spoiled and re-polish them. Then you get the bonus of the mat, preserver, and usually 1/2 a case. I have done this on occasion with interesting results. I have found several ruined vintage items for $5-10 each at flea markets and such. The only catch is that the plates are often bent or wavy and sometimes they have corrosion or scratches that will not come completely out, but for $5 each for the whole package it is hard to complain.-Larry

[jdanforth]

Race wrote:Wow… I just got my plates today in the mail. I spent $400 and my plates look as if a five year old silvered them Not only do they have deep scratches but silver dust clumps all over the place. What a mediocre plating company

Oh no! Sorry to hear that, Race. I would call them up and raise hell.

[AgNO3]

I wanted to let you all in on a method I came up with to keep my buffs clean. I found several empty 400 foot 16mm movie cans and they are the perfect size for a wheel, and you could even cut off a good sized piece of rouge stick and keep it in the can. The cans stack together and can be taped on the edges to keep out moisture.

I’ve tried to keep all my equipment having a vintage look to it and since one of my other hobbies is collecting antique electrical devices I took one of my old 1920’s GE motors and rigged up an old looking setup. I attached an arbor directly to the shaft and mounted the motor to a cast iron pedestal stand for grinders. I used an old surface mounted snap switch the same vintage as the motor to control it, but I did upgrade the setup with a ground wire to the motor frame.

This setup has worked very well for me and it is light enough to be moved out of the garage to keep the dirt flying off from coating all the other equipment inside.

I’ve buffed my first set of plates with it and am now ready for the plater’s ” title=”Very Happy” />

[Andy Stockton]

Pictures? ” title=”Smile” />

[jdanforth]

AgNO3 wrote: I’ve tried to keep all my equipment having a vintage look to it and since one of my other hobbies is collecting antique electrical devices I took one of my old 1920’s GE motors and rigged up an old looking setup.

This fills me with delight. We’re a strange bunch of people. Do you dress the part too? http://www.gentlemansemporium.com This might be fun too: http://www.rejuvenation.com Very steampunk.

[Mike Robinson]

Ouch,

I can sell you 10 clad silver sixth plates for 275.00. plus S&H

Mike

[Race]

Are the clad plates better than electroplated plates? 19th century style quality sounds pretty good ” title=”Very Happy” />

[corey r]

Well I think I’m ready. Not as broke this month as last so the iodine is on its way. I’ve been waiting to prep plates to send off to the platers until iI was ready to drop them in the mail.

Removed any deep scratches in my plates with 1200 wet paper. Polishing over the weekend. Wish me luck, I’ve polished copper for gravure before but not for dags. I’ll post results once I get the plates back from Thad.

[Andy Stockton]

Hey Corey – good luck. I will look forward to the results. I am in the middle of trying various methods on copper so hope to hear as many of your details as you are willing to share.

[supphaman]

A general question regarding pre plating copper polishing. In the past I have used pumice powder to give the copper an even matte finish prior to having it plated. This go around i’m trying to apply a mirror finish with a wheel buff instead. I have been able to get the plate nice and shiny, but not without some scratches. These appear to be on surface only and not gouged into the plate, but I can’t get them to completely disappear. I’m wondering if these will show up after plating? I’d just like some thoughts on how perfect the plates need to be as I don’t want to continue working on them unnecessarily; feels like i’ve been on the same 5 plates for ages already. TIA

[Pobboravsky]

Polishing Copper –A Masochist’s Delight

The number of polishing steps depends upon the surface quality of the copper with which you start and what you want in the way of a final surface quality. Even so-called “mirror finish copper” has an orange-peel surface. Silver electroplating will faithfully retain all the surface defects of the underlying copper substrate.

The steps below assume you are starting with very poor surface quality copper.

1. 320 grit (or 600 grit) abrasive paper attached directly to Bosch random orbital 5”-diam. backing plate (foam disc not used). Speed 1 – Try 1 to 2 minutes (I neglected to record duration.)

2. 30-micron 3M Trizact (green), pressure sensitive adhesive (psa) on 5-inch diam. foam disc. Water added from time-to-time with eye-dropper. Approx. 5 min for 5×7 inch plate.

3. 10-micron 3M Trizact (blue), psa on foam disc plus water as above; for about 5 min.

4. 5-micron 3M Trizact (orange), psa on foam disc plus water as above, ~ 4 min.

5. 3-micron 3M Polishing Paper w/ a few drops of water. 4 min. 3M adhesive sprayed onto back of pol’g paper and pol’g paper adhered to foam disc, overhang scissored off. 4 min.

6. 1-micron 3M Pol’g Paper as above.

In the interest of eliminating the first step in the list you may decide not to remove the orange-peel surface. (Some masochists have their limits.) However, if you start with deep surface scratches you will likely choose to eliminate them by doing the first step.

I don’t pretend to know if the final steps are really needed. Experience will guide you. Silver is far easier to polish than copper so you may decide not to do the last two steps.

Plates smaller than 5×7 require less time. Initial cost of Trizact is higher than conventional abrasive materials but it lasts and lasts.

This method can produce a surface free of scratches and orange peel. Consider this method in need of modification – it is just a jumping off point.

[Andy Stockton]

Irv – thank you. This is extremely helpful to me and I’m sure it will benefit many others.

Two questions:

1) How meticulous do you get in cleaning the plate between polishing steps? Wiping? Rinsing? Mounting the plate on a holder/surface reserved only for the grit in use each time? This is what seems to be the most time consuming part of the process as I am doing it now and maybe I am wasting effort.

2) Have you tried mounting all the various polishing papers directly to the ROS backing plate? Does using PSA on foam provide a distinct advantage?

Thanks again.

[Pobboravsky]

Hi Andy,

1. The copper (Cu) is adhered to plate glass (~12×14-inch) with four ~half-inch pieces of double sided tape. Some of the Trizact steps produce a slurry which spreads beyond the (Cu) onto the plate glass and would contaminate the next polishing step if it were not removed. The (Cu) is detached from the glass by sliding an artist’s palette knife under it and giving the knife handle a slight twist and then the Cu is rinsed under running water – front and back. The glass is then cleaned and wiped dry. All the steps are time-consuming and I welcome ideas that would shorten the time. A Masochist’s Delight is descriptive of the method as it now stands. The final surface quality is the best I’ve been able to achieve but getting there is not half the fun.

2. I mount each Trizact grade onto a separate foam disc because Trizact lasts for a bunch of plates. Peeling off the psa backed Trizact and replacing it with the next finer grade adds extra steps. The polishing papers last for doing barely one 5×7 and they must be replaced. The abrasive slurry produced during the Trizact steps would get onto the backing plate which would then need to be cleaned; mounting them on separate foam discs keeps the backing plate clean. Although I haven’t done it, a separate plate glass for each abrasive grade would reduce the amount of cleaning needed. Doing a series of Cu plates with, say the 30-micron Trizact, and then switching to the 10-micron grade to do the next step might reduce the time.

There is lots of room for improvement.

[supphaman]

I’m definitely interested in trying out an ROS. Maybe should have invested in one sooner as i’ve already spent enough money on buffing wheels, compounds and related misc materials to pay for a sander. Oh well, what’s another $150 right : o

One last question: I have been purchasing polished etchers copper at 2x the cost to reduce time spent on copper preparation. If I were to continue to use polished copper to begin with, what step of the process would you suggest I start? And just out of curiosity, is there a significant difference in prep time per plate using an ROS vs. wheel buff?

[Andy Stockton]

I have been using acylic plastic 14″x14″ as the polishing mount along with the double sticky tape method. It seems to hold up fairly well although I have not been using it very long either. I like the plastic because it is lightweight and not a breakage risk.

I have a separate sheet for each grit size. You still need to clean it between uses even if you do several plates in a row of one grit size because the plastic has to be reasonably clean and dry for the tape to adhere. By using one polishing mount per grit I don’t have to be as fanatic about cleaning however. You do save some time when doing a “production run” because you keep the same media on the ROS. I also have one Bosch foam pad for each Micron size.

I’m still investigating the various micron-grade papers available as well as using some graded alumina slurry I found from one supplier. The papers make somewhat less mess but I really have trouble deciding when a given piece of polishing paper has worn out. With the slurry I get fresh media each time. I haven’t yet worked out the costs exactly, but I think the slurry is cheaper. I also think it is just made up of water and graded alumina (since it separates into a clear liquid layer and a white layer after being left undisturbed for a while). My sense is that the slurry is cheaper – even pre-mixed.

The other thing I keep thinking about is lapping equipment – used by lapidaries and lens makers. They achieve some pretty fantastic polish on stone and glass and it would be a “set-and-forget” type process. Have you ever heard of anyone trying that? There are both rotary and vibratory laps.

supphaman – re the etcher’s plates, it sounds like a good idea but I haven’t been able to find it in the sizes I want. Do you cut your own?

[supphaman]

I’ve been purchasing 12″x18″ sheets and cutting it down to size; I have access to a large metal shear. The polished copper comes with a protective film on one side, keeping it scratch free. That leaves only the factory mill marks to buff out (note image). I actually have quite a bit of scratched copper lying about that got me frustrated trying to get the surface blemish free with 1200 sandpaper and emery compound on a buffing wheel. I realize that I need to exercise more patience, but getting scratches out of copper really gets to me. I’m wondering if the ROS would reduce my frustration making it possible for me to use up the scrap copper I have.

 

The second image is of a plate that has fine scratches from the buffing wheel that I can’t seem to get rid of. Frustrating indeed, i’m about to resort back to my old method of slurried pumice powder to achieve the mat finish. This method seems to yield good results, however, i’ve yet to have a polished plate plated for comparison.

 

Attachments:

You must be logged in to view attached files.

[Pobboravsky]

If the Cu-prepping method you use ends up giving final images with which you are happy, use that method. Going beyond that is a waste of time, money and effort.

Beginning daguerreotypists are faced with many problems — a perfect copper surface may be the least of the problems. I think getting a handle on sensitizing, exposure and development should precede the effort of getting a perfect copper surface.

---

Removing deep scratches Conjecture: I wonder if step 1. (ROS with 320-grit sandpaper)followed by wheel polishing might be shortest path to enlightenment. I haven’t tried it.

[supphaman]

Thanks for the advice Mr. P. You’re right, going beyond what is necessary would be a total waste of time and resources. I’m just a bit OCD, so even the most minor of imperfections with the plate are troubling to me. But if the scratches in the above image wouldn’t show up when plated I would be perfectly happy with the method. I suppose ill just have to plate it to find out for sure.

For convenience sake, I’d still like to try the ROS method. I have somewhat limited access to my wheel buff do to it’s location. I’m thinking that I could use the sander at my residence making it possible to polish plates at my leisure, meaning I could get a lot more work in. Ok, enough rambling, thanks for the response!

[Pobboravsky]

The Masochist’s Delight copper prepping method was done in Feb 2006. Today I tried it again, this time with an unusable electroplated plate which had silver blisters. The aim was to remove the silver layer down to the copper and to remove the orange peel on the copper. This reminded me of repressed memories worth sharing.

This 5×7 inch plate was 20-mils (0.5 mm) thick and it became convex in the 7-inch dimension after ROS sanding with 320-grit sandpaper.

(1) To keep the plate flat one should (ROS)sandpaper the back first and then work on the front.

(2) To minimize the dust generated by 320-grit sanding, use a sandpaper disc with its holes aligned with the holes in the backing plate. The dust will be vacuumed up by the sander as it operates and will be collected in the bag that fits on the back of the sander. (Now that I’ve told you about it I will use it next time).

(3) The 320-grit sandpaper produces a coarse matte surface making it hard to tell when the orange peel surface is removed. After a few trials you will find how long to run the sander for complete orange peel removal for your set of conditions (plate size, etc.) Residual orange peel will show up as the matte surface become finer after one of finer micron steps.

(4) My guess is that the 1-micron Polishing Paper is not needed. After the 3-micron step the copper will have a very fine matte surface and will be ready for silver plating. It isn’t necessary for the copper to be shiny.

[emf]

Ah, it’s nice to see that I’m not the only one going crazy trying to get copper polished. I’m just getting started with daguerreotypes, and I’ve accumulated most of what I need except the plates. I expected there to be a learning curve to polishing the copper, but I’m amazed how steep it is. Granted, I’ve never tried to polish anything except for an acrylic ash tray in 7th grade shop class, but still…

I’ve tried a lot of different methods at random, and my best results look similar to supphaman’s picture. I start with 2000 grit wet/dry sandpaper on a sheet of glass to try to flatten the copper and get rid of the orange-peel. Then I move on to the buffing wheel (6″ bench grinder), sometimes with tripoli first, then to rouge. I get to a point where I can get light scratches in one direction, and rotate it 90 degrees and get the scratches lined up in the other direction, but they’re always there, haunting me. When I try hand-polishing it with powdered chrome oxide or red rouge, if I press lightly it isn’t enough to get the scratches to disappear; if I press a bit harder (or keep at it for a half hour pressing lightly), the shiny finish clouds up after a hundred passes or so.

So far I’ve had other projects to work on when I got tired of polishing, but I’m running out of distractions. It’s great to hear what’s working for other people, though, even if I can’t make it work for me.

[drdag]

emf , you are really close. Nice to see you using the tripoli and rouge. Most important is the cleanliness of the rouge and its mop/s. If you put the rouge bar down on the bench and it picks a bit of dust or tipoli up that will scratch your metal. I use two rouge mops one for cleaning and polishing then a final polish one. I keep them in plastic bags when not in use. For my final polish I use cotton velvet on a padded board for a couple of minutes, then another cleaner one to get the mirror finish. Again any dust that falls on this can scratch and you have to go back to the mop. Polishing is a bit like making dags sometimes it just doesn’t happen for me and I walk away for a while.

Also don’t make the mistake thinking that the silver plating will somehow ‘fill in’ the scratches.

[Pobboravsky]

This is Irv Pobboravsky with some questions for emf.

Quote:

“I start with 2000 grit wet/dry sandpaper on a sheet of glass to try to flatten the copper and get rid of the orange-peel.”

1. Does the 2000 wet/dry sandpaper remove the orange-peel?

2. How thick are your plates? Could you expand on what is meant by “flatten the copper”

3. What holder do use for the 2000-grit? (backing?)

4. Do use the sandpaper with water?

Irv

[emf]

drdag, thanks for the words of encouragement. I’ve kept a separate buffing wheel for the rouge, but it sounds like I’m being much too careless leaving the bar and wheel out on the bench between attempts. I’ve ordered a few new buffing wheels that should be in this weekend, so I’ll try pretending the rouge is ebola.

Pobboravsky, I’m probably mis-using terms here. I’m using 16ga copper plates from Renaissance Graphic Arts. When they come, they look like supphaman’s first picture a few posts above. To start with, I was taking them straight to the buffing wheel with rouge or tripoli, and I’d end up with a nicely polished plate (save for the minor scratches), except a very slight waviness if you looked closely at the reflection. These ripples were all aligned in one direction, and I was assuming they came from the initial vertical lines you can see in the copper plate pictured. That’s what I meant by orange-peel, and sanding did take care of it.

When I was playing around with polishing the plates by hand (chrome oxide powder on velvet on a board), It looked like still only see two of the edges were getting polished unless I started to use a lot of pressure — I attributed this to the copper plate being having a slightly-curved surface. Maybe I bent it doing something stupid, maybe it just came that way. Anyway, I tried a trick I’d heard of overclockers using to ensure the surface of computer heat sinks were completely flat — take a piece of wet/dry sandpaper, lay it on a piece of glass (under a trickle of water) and sand it. I just held one edge of the sandpaper in place with my left hand (the wet sandpaper sticks to the glass pretty well to start with, so it’s not hard to keep it in place), and sanded the copper plate across it with my right hand — no holder, not very comfortable. To start with I’d only see the sandpaper scuffing up the surface on the two sides that had been polishing, but after 10 minutes or so the surface evened out. I was just using whatever 3M wet/dry sandpaper they had at the auto parts store, it wasn’t adhesive backed or anything like that.

I’m just making this stuff up as I go along… I haven’t gotten any plates polished well enough to send them out for plating, so I have no idea if what I’m doing has any value.

[drdag]

Dont worry everyone is making it up. Just do whats working for you, there is no right or wrong way, just different ways.

[Author]

Posts