Experiments To 're-Blacken' Hard Rubber

[amk]

There's a particular reason for blackening the ebonite on pens that mix ebonite and celluloid. For instance, I have a number of Pelikan Graphos and a Pelikan 100 that have a mix - eg the top of the cap in ebonite but the cap itself in celluloid. That looks just plain wrong when the pen is a nice shiny black and the top of the cap is a mucky matt brown.

[Nethermark]

Hello,

I did some experiments with a product that I created from simple products (alcohol, mineral oil, emulsifier, cleaning agent ...). you can see the first results on this thread:

 

http://www.stylo-plume.org/viewtopic.php?f=9&t=18644

 

Give me your opinion?

 

Very interesting results! Could you give us some more details on the products you use and the proportions in which you use them? Maybe also a bit about why precisely these product? I try to understand how your method works, but maybe I'm prying a bit too much here...

 

Jan

[txomsy]

Neat. I'll await your post about crack repairs with expectancy.

[Dr.X]

A better way to use Mark Hoover's deoxidizer:

 

Had a "DUH moment the other day. If I don't want the stuff to dry out, why don't I wrap it in Saranwrap? Like the guys who re-lighten yellowed plastics from the 80s with peroxide.

 

IT WORKS.

I've tried leaving it on overnight, and though I'm not sure it damaged the pen (barrel only from a Waterman 52), it seemed like there was some slight swelling around the area I wrapped. Or it could be my imagination. Anyway, not doing that again.

 

But leaving it on for 1-2 hrs definitely made a difference: now I get brown rubber-sulfur residue on the cloth every single time I use the product on the same (oxidized BHR) pen

 

I also tried heating the pen before applying the paste, but I don't think it made a difference. Thought being that chemical reactions often work better at higher temps.

 

It is interesting that different pens react differently, though it makes sense - different age and manufacturing techniques, including amount of sulfur added, I suspect.

 

I hope this helps someone else.

Edited March 9, 2020 by Dr.X

[FredRydr]

There's a particular reason for blackening the ebonite on pens that mix ebonite and celluloid. For instance, I have a number of Pelikan Graphos and a Pelikan 100 that have a mix - eg the top of the cap in ebonite but the cap itself in celluloid. That looks just plain wrong when the pen is a nice shiny black and the top of the cap is a mucky matt brown.

 

Like this '50s Aurora with black celluloid body and "black" hard rubber piston knob.

[siamackz]

I use zip lock bags and place a clip, minimising the amount of product that needs to be used. Check out the restoration notes on a Haro that I just deoxidised https://www.fountainpennetwork.com/forum/topic/331395-free-restoration-service/page-10?do=findComment&comment=4300710

[Dr.X]

Thanks Sia.

 

Same idea. Your way is better in some ways (you can re-use the product), but

if it is peroxide-based, won't exposure to light cause the peroxide to lose efficacy? Hence the opaque bottle.

 

And - do you ever get the sticky stuff inside by accident? Like through the breather holes in the cap? That would be a PIA to remove!

 

Do you ever use heat?

 

Overall, with this method I'm sticking with Mark's product rather than experimenting...for now. (I can't help it, I'm a scientist)

[siamackz]

Thanks Sia.

 

Same idea. Your way is better in some ways (you can re-use the product), but

if it is peroxide-based, won't exposure to light cause the peroxide to lose efficacy? Hence the opaque bottle.

 

And - do you ever get the sticky stuff inside by accident? Like through the breather holes in the cap? That would be a PIA to remove!

 

Do you ever use heat?

 

Overall, with this method I'm sticking with Mark's product rather than experimenting...for now. (I can't help it, I'm a scientist)

I dont know if Marks product is peroxide based, to be honest. I just use it once and throw it away as I dont want to contaminate the rest of the bottle. By using zip lock bags I can use just enough and throw it away without feeling too bad.

I have got the sticky stuff inside and its a pain. I clean it out liquid paraffin/mineral oil, but its a pain! So, I close the breather holes with tiny pieces of blue tac. In the past, I have also filled the cap and barrel with cotton just in case the blue tac comes off. I havent used heat yet.

I have found that this product (Hoovers) works well on some pens and just wont on some.

[Dr.X]

I have found that this product (Hoovers) works well on some pens and just wont on some.

 

Same here. Which is echoed in other threads on the subject.

[nono50]

Hello,

The mixture I'm testing is based on sodium percarbonate. The combination of alcohol, emulsifier, water and cleaning agent with a high proportion of oil (here mineral) does not (apparently) swell the ebonite.

The passage to the magic sponge attenuates the oxidized overcoat (I make only a gentle friction sufficient to remove the brown layer).

I will make photos when I can treat objects (without polishing) after 3 to 4 weeks of drying.

But already, you have an idea with my photos on the link given in my previous message.

I'm in my 4th week and the product is still active (you just have to shake it vigorously).

This mixture barely comes down to a few euros (dollars) in raw materials.

[siamackz]

There is no conclusive evidence on whether boiled linseed oil, mineral oil, or wax, will slow down the oxidisation process of BHR. So, I thought I’d do a little experiment of my own. I had a cracked barrel of a rather worn out Waterman and thought it would make the perfect subject. First, I removed the oxidised layer so that the barrel is an even black. I was not gentle, I won’t lie, but there was no need to be. I have put linseed oil, liquid paraffin, and renaissance wax, and nothing, on different parts of the barrel and have now kept it away in an open box in my closet. The relative humidity in my city is about 65% right now and I expect it to rise steadily to 90% by July. I’ll update this thread with a picture every month. It’s not a perfect experiment, there are several confounding factors - sure, but hopefully it tells us a little something at least.

 

[Bibliophage]

I would expect the worst reaction to be the section with boiled linseed oil. It's hardening action is exothermic. I really love the stuff for wood, but I throw my wiping rags into a thick metal can after use.

[Dr.X]

I would expect the worst reaction to be the section with boiled linseed oil. It's hardening action is exothermic. I really love the stuff for wood, but I throw my wiping rags into a thick metal can after use.

 

Interesting. I use linseed oil all the time as a final step after de-oxidizing my ebonite pens. Makes the rubber darker.

 

Sia - would putting the test object in a sunny window make any sense?

[nono50]

Hello,

Linseed oil?

But how do you get rid of the smell?

I personally use carnauba wax (It smells pleasant)

Edited March 13, 2020 by nono50

[Bibliophage]

 

Hello,

Linseed oil?

But how do you get rid of the smell?

I personally use carnauba wax (It smells pleasant)

 

 

Linseed oil, or technially "flax seed oil" if you buy it in the health food aisle of a store for 100x the price, has a very mild odor, I've found. It also tends to vanish after the hardening/oxidation process completes. I like linseed oil and beeswax for a finish on hardwood.

 

[siamackz]

 

Interesting. I use linseed oil all the time as a final step after de-oxidizing my ebonite pens. Makes the rubber darker.

 

Sia - would putting the test object in a sunny window make any sense?

Good idea with the sunny window to speed up the process!

Do you use raw or boiled linseed. I understand they are quite different - the latter turning into a solid coat but the former not doing so.

[Dr.X]

Turns out there are many ways to extract oil from the flax seed and then refine it. Most are not cheap.

 

I've tried only 2 types: raw and "refined", the latter made by Winsor and Newton for use with oil paints.

 

The latter is "alkali-refined" and dries more quickly than the latter, though I wipe it off within 24 hrs when it is still 90% wet. The "raw" version I own never dries, as far as I can tell. I prefer the Winsor and Newton version, but am open to input.

 

I find the smell non-objectionable, but YMMV.

 

I chose linseed oil over mineral oil because I read somewhere that it may have been used in the manufacturing process of ebonite. But I am open to being corrected.

[Dr.X]

In researching the preservation of plastics (ebonite being one), I’ve come across some information that is different. For example,

 

https://cool.culturalheritage.org/waac/wn/wn24/wn24-1/wn24-102.html

 

https://www.canada.ca/fr/institut-conservation/services/conservation-preventive/lignes-directrices-collections/soin-plastiques-caoutchoucs.html

 

Ebonite is primarily degraded by oxygen and water. UV light discolors it and makes it brittle, but the sulphuric acid released appears to play a larger role in the deterioration of this material.

 

Similarly, acidic by-products of cellulose nitrate stabilized with camphor (celluloid) degradation appear to be one of the main culprits and a target for conservation interventions. It also appears that celluloid is degraded by light and water much more than has been discussed in these forums.

 

https://cool.culturalheritage.org/jaic/articles/jaic30-02-003.html

 

It seems that epoxidized soybean oil has been used to slow down the damage to celluloid. I tried placing an order with Sigma Aldrich for it but I anticipate they will decline the order because they only sell to specific types of customers (i.e. laboratories.)

Edited March 14, 2020 by Dr.X

[Dr.X]

Actually, I was wrong about light and its effects on ebonite:

 

"The mechanism for light catalysed oxidative degradation is that the energy of UV light may be sufficient to break a C-H bond and generate a radical species which can then react with oxygen to initiate the same chain reaction sequences as occur in direct oxidation. Two types of protective agents are available, the ultra violet absorbers (UVA's) and the hindered amine light stabilizers (HALS). The UVA's compete with the olefinic double bonds for the available energy and dissipate it harmlessly. It is important to remember that the absorption of light follows Beer's law so even if one has a UVA present it would give no real protection to a material less than about 0.5 millimetres. HALS operate by a different mechanism which is still not completely resolved but is believed to be a radical trap. It thus operates throughout the UV-transparent sample and is often used in conjunction with a UVA."

 

From:http://www.bouncing-balls.com/index2.htm

[Zookie]

Sia, Your posts have been a real inspiration to me, and convinced me to try my hand at pen repair.

My first victim, excuse me, I mean patient is an old Inkograph that I've had in my parts box for a couple of years.

I first used a hair dryer to warm up the section, and it pulled right off. No threads. The sac was dry, and easy to remove.

The lever and j-bar are fine.

Knowing that alcohol is a good solvent for shellac, I soaked and cleaned the section in it until I got the wire loose, again, no problems. It moves freely now.

Then I tried to restore the hard rubber finish. My photos aren't so good, but the pen was a brownish, greenish mess. I don't know if you can tell from the photos. What I used to clean it is my #1 go to for polishing pens. It's very gentle and didn't bother the engraving.

You said that you use some kind of chalk to fill the engraving? Will any old chalk do?

Anyway here are some photos of my work so far. All I need is a sac and that chalk.

Thanks so much!

Doug

 

 

 

 

 

Edited March 21, 2020 by Zookie