Author Topic: A method for polishing heavily pitted Bakelite that worked for me  (Read 8681 times)

Offline TelePlay

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This information was originally posted in another topic I started of what became a project phone. Since this method was just a part of that topic, it may be hard to find so I am duplicating the Bakelite restoration and polishing parts of that topic here. A lot has been written about restoring Bakelite and after reading it all and having a very pitted handset to work on, I came up with this method, that worked for me. It all in one place here for posterity, and convenience.

The original topic was AE D1 Continental clone? project and the Bakelite method that work for me is as follows.

The first picture is of the handset after stripping off the gold paint.

The method I then used was as follows:

---------------------

  1 )  If painted, first, remove the paint. I used Citri-Strip, two applications did it for this handset. I use aircraft paint remover for tougher paints.
  1a) If not painted, start with next step. 
  2 )  I go over the phone with 000 steel wool and Brasso as many times as needed to clean the Bakelite surface.
  3 )  I hand sand the Bakelite using 800 grit wet/dry sandpaper using Brasso as the wetting agent.
  4 )  I sand an area until the Brasso dries out and becomes a black paste like coating on the Bakelite
  5 )  I then use a Ryobie orbital buffer to remove the Brasso paste.
  6 )  I repeat the sanding process (Steps 3, 4 & 5) until the surface is smooth or as smooth as desired.
  7 )  I use a cotton wheel with white polishing compound on a 3400 rpm buffer
  8 )  I buff in different directions each time I add compound to the wheel.
  9 )  When looking well polished but still a bit dull, I move over to a red polishing compound with a different cotton wheel
10)  Again, I buff in different directions each time I apply more compound.
11)  When satisfied, I wipe the buffing dust off with a clean cotton rag and that's what you see in the picture.

The third process step, which I haven't tried yet, is to go to a polishing compound designed for plastic and a softer wheel which may put a gloss finish on what is seen in these photos. I start with 800 grit sandpaper. It may be quicker to start with 600 and move up to 800 or even 1000 before heading to the buffer. EDIT #1 - Stay away from 600 grit, start with 800, period. EDIT #2 - 600 grit dry sandpaper works well to get rid of most of the pit highs and can be used until nearing what you want or expect to be the final surface. It does leave the Bakelite dull from the grit but that is easily removed with the 800 grit/Brasso wet sanding. The 600 grit dry reduces the amount of time needed to get to a smooth finish.

The bottom (after) picture of the combination photo shows very minor pitting which could be removed with more sanding before buffing. This is bare Bakelite that's been sanded and buffer - no oils, waxes or polishes have been applied. Overall, it's a question of what you want, what you are satisfied with. You can always go back to the sandpaper if you don't like what you see after buffing and repeat the method until satisfied.

Any Brasso on the sandpaper will re-liquify simply by adding another small portion of fresh Brasso to the paper. I simply hold the paper over the Brasso can opening, shake it once, and that is enough to wet the paper for a few minutes of hand sanding. Water does not work with this process and the handset does get warm to very warm when buffing.

---------------------

The high magnification photos have a reference ruler on the left. The lines on the ruler are 0.1 cm apart. The side by side photos are identical with the ruler laid on top of the handset on the left. On the after photo, you can still see some pits but without the high magnification, to the naked eye, it looks very nice. I finer buffing compound may make it even better but haven't taken the time to switch wheels yet. The bottom photo shows the approximate location where the two photos were taken.

The last photo shows in the red circles the approximate are in which the close ups were taken.

xzzx-polishing bakelite-xzzx
« Last Edit: November 21, 2016, 08:37:29 AM by TelePlay »
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Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #1 on: December 15, 2014, 10:33:09 PM »
Next phase of Bakelite polishing for me worked out well. Got another painted D1 and stripped the creme colored paint off everything. The F1 handset has a good surface but the receiver cap was very rough and pitted. Very rough so I came up with this restoration solution and tool.

Bought a cheap, small, variable speed bench grinder with a 36" flexible shaft attachment some time ago. Not real happy with the motor. It is cheap and has little torque. Easy to stall when using it as a grinder so didn't use it much. But, as I started to work on the cap in question, I  looked at that "power" tool and got an idea while working the cramps out of my fingers.

In the first picture below, the grinder set to about 7,500 rpm is Photo 1; where the shaft attaches to the grinder is Photo 2; the wool covered working end of the flexible shaft is Photo 3; and an on/off foot switch I made some 30 years ago is Photo 4 (the D1 base plate is next to it to show size).

To make the tool, I took a 1" diameter Dremel buffing wheel and wrapped a layer of 00 steel wool over it and down around it the shaft. I taped the wool down around the shaft and secured the tap with a rubber band. More wool was added by layering it on top of the existing wool as needed during the Brasso polishing phase.

I started by sanding the cap by hand with 600 grit dry sandpaper. I could watch what was coming off by wiping the dust away which showed the remaining pits, peaks and valleys filled with dust. I sanded until the cap looked quite smooth, and quite dull from the sandpaper.  (NOTE: some say one can sand Bakelite too much an expose the core and if that is the case, sand carefully.) I could have sanded more but decided I was happy with what I had at that point in time.

Cleaned off the dust and put a blob of Brasso on the cap. Smeared it around with the steel wool on the tool and hit the foot switch to begin polishing the Bakelite. 7,500 seemed to be a good speed to polish the cap without sending the Brasso flying of in every direction.

Kept working the tool over the surface until the Brasso dried. Wiped off the Brasso dust and repeated that step several more times putting new layers of wool on the tool as needed.

When the surface of the cap started to look shiny, I started to use 000 steel wool until the Bakelite had a near gloss finish. I then took the cap to my bench buffer and first used white rubbing compound on a stiffer wheel followed by red rubbing compound on a softer wheel.

The results of about 15 to 20 minutes of total work can be seen in the bottom two pictures. The cap had one deep pit that still has creme paint in it. Could not sand that pit out because it was too deep so just left it. The pit is at the 3 o'clock position in the "after" photo and about the 10 o'clock in the "before" photo.

The "after" cap is right off the buffing wheel. No wax, oil, polish or SSS has been applied. It is a totally dry, smooth and near gloss Bakelite surface. And, yes, I was wearing a white tee-shirt with red letting on the front of it when I took the "after" photo, the reflection in the cap.

This worked for me. I'm passing my method along to anyone who may find this method and "power tool" useful in restoring Bakelite.

« Last Edit: November 21, 2016, 08:40:32 AM by TelePlay »
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Offline Doug Rose

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #2 on: December 16, 2014, 07:35:03 PM »
Nice job. Looks like it is brand new bakelite!
Kidphone

Offline Under Dog

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #3 on: December 17, 2014, 11:59:27 AM »
Looks great!  I have a couple of my old phones I've been anxious to get to but work has been killing me lately.  On the positive side, I will get some good time off starting next week.  But the house will also be filled with extended family, so who knows what sort of "pay" time I will get...

Well done!

Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #4 on: November 13, 2016, 12:35:44 PM »
Continuing of this theme, for as long as I've been on the forum there have been two camps on sanding Bakelite. One saying don't sand because if you sand through the thin shiny layer created by the metal mold, you will end up with a pitted spot or area and have ruined the item. The other being sanding is the best way to get Bakelite smooth and those who used that technique have never experienced the "sand through" problem.

Some time ago, I bought two large boxes of handsets, mostly SC but some Kellogg, and they came dirty and some looking like they recovered them from the Titanic last year. One was a Kellogg that had the outer half of the receiver cup broken clean off. Other than that, the Bakelite surface was in the same condition most other handset are in when found, having a dull shine with some browning and and pits. Nothing major, just old. We've all seen the rough surface of broken Bakelite and the very thin smooth layer created by the mold. This is how it looked like, at least part of the broken cup, to show the starting surface, not which I worked on (didn't get a picture of that) but as an example of what it looked like . . .



This broken handset gave me a chance to try an experiment I'd been thinking of for some time. First, I took a metal file to the thick part between the receiver metal contacts, the thick part where the cup attaches to the handle, to knock off a high point and create a flat surface. After just filing down to a small flat spot which was very dull, I took it to my 3400 rpm buffer using white compound and then red. The whole experiment took 5 minutes. The results are on the left under the yellow arrows. The yellow arrows are pointing out the thickness of the mold surface. The green box shows the broken Bakelite untouched and the orange box shows the broken Bakelite that was touched by the buffer wheel, the tops of the high points were taking on a shine.



The first trial, the small spot, turned out well, smooth and shiny but it showed file marks. As such, I started over on that small spot by leveling most of that area with a Demel cutting tool. It was larger, flat and very dull. I used the above method starting with 800 grit sandpaper wet with Brasso and after sanding in both directions two time about 15 seconds each, moved up to 1000 grit doing the same thing. After that I went to the buffer, as above, and with about 3 minutes of buffing time total, I ended up with the surface show on the right in the above image. The green circle shows the rough, broken Bakelite and the red arrow shows the surface transformed from rough broken Bakelite to a shine better than anywhere else on the handset as received.

In a full view of the broken cup below, the yellow boxes show broken Bakelite, the green circle shows the existing handle and inner cup shiny surfaces and the red circle shows the test area right off the buffer, not wax or any other surface treatment applied.



This image is the same area taken from the other side of the, the red areas showing the original broken Bakelite, the yellow arrow the test area.



The above images are attached below and can be click on to enlarge to see detail. Only thing I should have done as start with 320 grit sandpaper working up to 400 and 600 before going to 800 to remove some of the marks made by the Dremel cutting tool when creating the flat surface. I can still do that and if I have time today, I could start with 320 and see what difference that will make in the final surface.

So, it seems even if one would sand through the very thin shiny mold layer, it is possible to get the surface back to near mold quality.
« Last Edit: November 21, 2016, 08:42:38 AM by TelePlay »
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Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #5 on: November 13, 2016, 10:23:28 PM »
The final test, or experiment using the damaged handset.

First buffed the damaged end of the handset to get a nice shine.

Then, used a 100 grit sanding stick to create a flat spot about a nickle in size. This would be an area sanded through the smooth mold formed outer layer to the "rough" Bakelite under that thin, outer layer.

Started with 320 water wet sandpaper, then 400 and 600 both water wet. Then used 800, 1000 and 2000 grit wet with Brasso buffing off the dried Brasso with my orbital polisher between polishings. Upon inspection, I noticed a sand mark so went back to the 400 grit and repeated each step. The sand mark was go so took it to the buffer, first white and then red compound. Buffed with red until I could clearly see both tubes of my overhead work light in the cup area.

I could not just sand the damaged area so the whole cup area was subjected to the sanding and polishing procedure above, making the camera image clearer in the restored Bakelite.

The first image below are the as found, sanded flat and restored cup images from left to right.

The image just below that is the same thing but showing my camera and finger reflection in the left and right image in the yellow circle and the image on the right shows distortion of the center light due to the now flat spot in the once round cup. The distortion can be felt but can not be seen unless the cup is held in just the right light.

So, Bakelite, broken or sanded through can be restored. This ends my experimentation with Bakelite restoration.
« Last Edit: November 21, 2016, 08:45:30 AM by TelePlay »
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Offline AE_Collector

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #6 on: November 15, 2016, 12:19:30 AM »
Excellent documentation John. It makes good sense that you would be able to sand and buff Bakelite back to a factory shine or at least extremely close to factory shine.

Presumably there may be some differences in Bakelite that might make some types more difficult to get a durable shiny finish. I know little about Bakelite but have heard of it containing fillers etc that might not hold a shine when sanded and buffed even though the original surface was shiny.

In Bakelite AE sets I gave noticed what appears to me to be different degrees of glossy shine from one to the next. I have no way of knowing what one set has been through compared to the next but some that are completely clean and don't appear to be pitted at all just don't have the same thick glossy look that other sets have. I don't have a buffer so my observations are just from having cleaned and polished by hand.

I have been looking at buffers and or grinders a bit lately. I always heard that a 3400 rpm buffer was way to fast to touch plastic so this has prevented me from buying one several times now. While there are 1700 rpm buffers out there the 3400's are much easier to find with several models and price ranges to choose from. There are variable speed grinders so I keep wondering why no variable speed buffers.

Terry

Offline WEBellSystemChristian

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #7 on: November 15, 2016, 10:05:04 AM »
Great work, John!

Are we sure that irreversibly dull Bakelite is caused by wear? What if it's simply reacting negatively to skin oils over time, and what if the layer exposed to oils can't be brought back unless completely removed?

Have we ever seen Bakelite housings with the level of dullness and pitting seen on Bakelite handsets? I don't think wear has ever caused pitting, and I've found that worn Bakelite can always be brought back to gloss.
Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford

Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #8 on: November 15, 2016, 10:33:41 AM »
Just a quick note. There was an composition error in this post

http://www.classicrotaryphones.com/forum/index.php?topic=12264.msg176346#msg176346

Since I was trying something new, I created the reply in a back room area so I could do a lot of modifying without risk of people seeing a work in progress. What I was doing was attaching the pictures and the bottom of the reply and then went back in and one image at a time, linked them to within the text of the topic. I then merged that reply into my Bakelite restoration topic. It looked good to me. I was not aware, until today, that the image number of the merged topic stayed the same but so did the topic number, it was not changed by the forum software to the current location when merged.

As such, the images in the merged topic looked like externally linked images but with a broken link. I have now revised those links within the test so reading the test will make more sense.

Next time I do that type of reply, I will do it within the topic where it will finally reside. Leaned another lesson about externally link images developing bad links. Sorry . . .
            John . . .

              

Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #9 on: November 15, 2016, 11:36:30 AM »
I have been looking at buffers and or grinders a bit lately. I always heard that a 3400 rpm buffer was way to fast to touch plastic so this has prevented me from buying one several times now. While there are 1700 rpm buffers out there the 3400's are much easier to find with several models and price ranges to choose from. There are variable speed grinders so I keep wondering why no variable speed buffers.

Yes, I use a 3450 RPM extended shaft buffer. There is a great topic on buffers on the forum and yes, 3450 is very fast for plastics - can easily melt or burn any plastic at that speed, from experience. The slower 1700 RPM buffer is recommended for plastic.

This is the buffer I bought before the melting plastic replies were posted, or I found them.

http://www.eastwood.com/eastwood-1-2-hp-buffmotor.html

It works great for metal and Bakelite. Actually, strongly pressing the Bakelite against the wheel to the point of heating the Bakelite works best and that takes pressure and speed and time. Doing that with plastic will ruin the plastic. The warmer the Bakelite gets, the better the shine.

As a test, I just buffer another part of that handset. Within the first few seconds, it just looked buffer. When the reflective shine began to appear, the temperature of the Bakelite area being buffer was 160 degrees F using a surface temperature reading device. Never check the surface temperature before but have felt the "hot" area after buffing. When removed from the wheel, the temperature drops rapidly, gets back do to 100-110 F within 10 seconds. So, it seems the Bakelite surface is becoming more "fluid" with the increased temperature and "melting" to create a more "mld like" surface, possibly "smearing" the polyoxybenzylmethylenglycolanhydride (pure Bakelite) over the wood fillers that can not by themselves be polished? Don't know. BTW, pronounced poly-oxy-benzyl-methylen-glycol-anhydride, guess that's why it's called Bakelite . . .   ::)

As a side note, I do use this buffer for plastic but the plastic has to just barely touch the wheel, the plastic has to be kept moving and you have to buff off of edges, not toward edges, to keep the wheel from catching a sharp edge and quickly burning it off and the time on the wheel is very short in any one area to keep the plastic from heating more than a few degrees. It takes a lot of trial and error to buff plastic on a high speed buffer, can be done but it is risky, even with practice.

So, just a quick buff at 3450 RPM will "polish" an existing surface, not improve the reflect-ability of the surface. Strongly buffing the existing surface will increase the reflect-ability of the surface moving to a more mirror like surface. This can be seen both the light bulb and the camera reflections in this image. The light bulbs became a bit sharper (less diffuse) and the camera reflection more clear (the yellow circle).



I was not trying for a mirror finish, just the ability to bring sanded through Bakelite to a finish like the surrounding area. That was accomplished. I think if I buffed the handset cup more, it would develop an even better reflective surface. May try that later.

And from earlier in the topic, this handset was cleaned with acetone to remove surface oils and then restored to a nice shine using my method.

http://www.classicrotaryphones.com/forum/index.php?topic=12264.msg129509#msg129509



This handset was quite dull and pitted from many years of use and it came back by sanding off the high points and strongly buffing the sanded surface to a nice shine. Could I get a better reflection? Possibly, but that was not the goal in the first post of this topic.

So, along those lines, the only question remaining is how smooth can one get a rough Bakelite surface by sanding and buffing. The problem I have with doing that is diminishing returns, is it worth the time and effort to get just a little bit more shine or is 90% or so of mirror like shine acceptable for display? That's a personal decision and I'll leave it at that because it depends on what someone wants in the end. And, the buffed parts look much better when seen in total in normal light than what appears in an image - the camera is a very unforgiving device.


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Offline SUnset2

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #10 on: November 16, 2016, 01:48:22 AM »
For what it's worth, when buffing thermoplastic I use an unsewn wheel.  It's not as easy to burn the plastic as with a sewn wheel.  Bakelite is tougher, and can stand the heat.  You need to be careful, but it's a lot faster than polishing by hand.

Offline Ktownphoneco

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #11 on: November 16, 2016, 09:22:16 AM »
Good tutorial John !   I agree with all of the information you've provided.    I've been sanding and buffing bakelite for probably about 20 years, and tried numerous methods, some good, some bad, and finally settled on the method you employ.       I discovered a polishing compound you may want to try with your buffing wheel.    It's made by DICO, in Utica, NY., and it's called, "PBC", or plastic buffing compound.    I buy the round tubes of PBC, but I also think they make it in bar form.    It works well in both bakelite and plastic.
The one thing I've found with bakelite, and which you touched on, is that I firmly believe telephone companies that produced products in bakelite used different methods and fillers to produce their products.      I say that because, as you have also pointed out, results can vary greatly, from one thing to the next while using the exact same procedure for each. 
Being in Canada, and a restoring a lot of Northern Electric Uniphones, I've noticed different results from one Uniphone case to the next.    I've also noticed that the Uniphone cases made with the brown swirled bakelite, or walnut color as the company called it, in most cases polishes a lot better than the black bakelite.
Here are some pictures of Uniphones that I've polished over the years.    Just click on them, and they'll enlarge.
The other thing I wanted to mention with respect to polishing plastic, is the use of a buffing wheel called a "string buff".     It works well when polishing parts with a lot of "nooks and crannies" , as the string contours itself around whatever is being polished.

John if you'd like to try the DICO PBC polishing compound, let me know and I'll put half a tube in the mail for you to try.

Enjoy the day.

Jeff Lamb
 
« Last Edit: November 16, 2016, 01:49:15 PM by Ktownphoneco »

Offline TelePlay

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #12 on: November 16, 2016, 09:50:42 AM »
John if you'd like to try the DICO PBC polishing compound, let me know and I'll put half a tube in the mail for you to try.

Jeff,

Thanks for that information and the great pictures. And, yes, a string or unsewn buffing wheel is much preferred for plastics.

Reading your reply, I was thinking Bakelite mixed with fillers seems to be a lot like pot metal in that the metals within any piece of pot metal can vary and can be seen when highly polishing the surface. If the quality control over the filler of type, particle size and concentration is not real tight and varies, that would explain and/or confirm what you said and what I've found when working with and polishing Bakelite.

As for the DICO PBC, thanks for the offer. I did a quick check for it and found that I can buy the following stuff from an ACE hardware store about a mile away from me, for $5.25, today. Seems like the same thing by name and source (Utica NY). If this looks like what you use, let me know and I'll go get a tube today and try it.
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Offline Ktownphoneco

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #13 on: November 16, 2016, 10:11:07 AM »
Thanks John.    That "IS" the stuff !    I should have mentioned that Ace carry it, but forgot.    I find it works well.    Let me know how you like it.   Yes, I agree with the "pot metal" analogy and Bakelite composition.   I can't imagine they measured things down to the "gram", and I would also assume the ingredients came from the lowest bidder, which meant that most likely there'd be a variance in the quality of the raw materials themselves, from one source to another.

Jeff

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Re: A method for polishing heavily pitted Bakelite that worked for me
« Reply #14 on: November 16, 2016, 01:09:19 PM »
Good tutorial John !   I agree with all of the information you've provided.    I've been sanding and buffing bakelite for probably about 20 years, and tried numerous methods, some good, some bad, and finally settled on the method you employ.       I discovered a polishing compound you may want to try with your buffing wheel.    It's made by DICO, in Utica, NY., and it's called, "PBC", or plastic buffing compound.    I buy the round tubes of PBC, but I also think they make it in bar form.    It works well in both bakelite and plastic.
The one thing I've found with bakelite, and which you touched on, is that I firmly believe telephone companies that produced products in bakelite used different methods and fillers to produce their products.      I say that because, as you have also pointed out, results can vary greatly, from one thing to the next while using the exact same procedure for each. 
Being in Canada, and a restoring a lot of Northern Electric Uniphones, I've noticed different results from one Uniphone case to the next.    I've also noticed that the Uniphone cases made with the brown swirled bakelite, or walnut color as the company called it, in most cases polishes a lot better than the black bakelite.
Here are some pictures of Uniphones that I've polished over the years.    The other thing I wanted to mention with respect to polishing plastic, is the use of a buffing wheel called a "string buff".     It works well when polishing parts with a lot of "nooks and crannies" , as the string contours itself around whatever is being polished.

John if you'd like to try the DICO PBC polishing compound, let me know and I'll put half a tube in the mail for you to try.

Enjoy the day.

Jeff Lamb
 

Jeff;
Those are absolutely gorgeous, especially the Walnut.
D/P

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