Adventures with acetone

Some things I have learned through trial and error in the last few days.

1) A No 2 or No 3 brush is the perfect applicator. Although a cheapie with synthetic bristles is plenty good enough, no need to buy a sable brush. You can get a pack of 5 or 6 brushes for $2 without any trouble.

2) Acetone will glue together a celluloid scale that has been snapped in half (this was the error part of 'trial and error'). Careful sanding and painting will make the join hardly noticeable, but not invisible. All you have to do is lightly paint each end with acetone and gently push the ends into place and then let them sit whilst supported for 15 minutes and you will have a solid join. Solid enough to re-pin a razor within 30 minutes of joining the two halves together if you are like me and have no patience.

3) Using a brush dipped in acetone to get underneath inlays as they start to lift is a very efficient way of removing metal inlays without damaging them.

4) You can glue inlays into new celluloid scales using acetone. Firstly you clean and shape the inlay for the new scales. Then liberally paint the back of the inlay with acetone. Quickly place the inlay into position on the new scales and lightly but firmly press the inlay against the scale. Use your fingernails or toothpicks to hold the inlay in position. After about 30 seconds the acetone will have melted the celluloid around the inlay and re-set. This leaves the inlay set into the side of the scales.
I would suggest that you use masking tape to mask off the area where you want to fit the inlay.
If you goof up you can use acetone to lift off the inlay, wait for the celluloid to dry out, sand the scar back with 1500+ sandpaper and try again. It's better not to goof up, but if you do it isn't the end of the world.

Excellent post. Now I can't wait to have the opportunity to give this a test ride. I just love to find these little technical tips to add to my own bag of tricks. Thank you for the help with plastic. I'm not all that fond of that stuff but we do have to bother with it in this day and age.

Very Respectfully

Chasmo

Pauly,

Could you post some pics of he finished product, would be interested to see how it went. Thanks for posting. Look forward to some pics.

Sweet tip, thanks for sharing!

Regards
Louis.

Acetone works OK with celluloid, but it does not give a full strength solvent weld. Nor, in my opinion does it disappear cracks as well as other chemicals. I use MEK on celluloid fountain pen repairs and it is much better than Acetone. There is another solvent which does give a full strength weld, but it is not available to the general public and is exceedingly toxic to use.

I have been repairing celluloid fountain pens for 6 years and have found that cracks welded with acetone are not as strong as MEK welded joints. I very strongly suggest against using any cyanoacrylates on celluloid as they just don't have the long term holding power of a good solvent weld. Also super glues are hygroscopic and will eventually fail when subjected to water (as razors often are).

The OP's suggestions are excellent, but I would rather wait at least 24 hours (a week is better) before working on any solvent welded joint. This ensures that all solvents are flashed out of the material and the weld has properly set.

Cheers,
Sean

I've lost one inlay to a tight fitting box, so the idea of letting them cure for a week is a damn good one.

Where does one get MEK?

Quote:

---

Originally Posted by SMG

Acetone works OK with celluloid, but it does not give a full strength solvent weld. Nor, in my opinion does it disappear cracks as well as other chemicals. I use MEK on celluloid fountain pen repairs and it is much better than Acetone. There is another solvent which does give a full strength weld, but it is not available to the general public and is exceedingly toxic to use.

I have been repairing celluloid fountain pens for 6 years and have found that cracks welded with acetone are not as strong as MEK welded joints. I very strongly suggest against using any cyanoacrylates on celluloid as they just don't have the long term holding power of a good solvent weld. Also super glues are hygroscopic and will eventually fail when subjected to water (as razors often are).

The OP's suggestions are excellent, but I would rather wait at least 24 hours (a week is better) before working on any solvent welded joint. This ensures that all solvents are flashed out of the material and the weld has properly set.

Cheers,
Sean

---

Sean,

Thanks for the acetone advice, much appreciated.

Quote:

---

Originally Posted by Pauly

I've lost one inlay to a tight fitting box, so the idea of letting them cure for a week is a damn good one.

Where does one get MEK?

---

Not sure where you would get it in Queensland, I got mine from an old job I had where they had a large paint booth. Methyl Ethyl Ketone is MEK, its not great for you by any means, but does work wonders on celluloid and other plastics.

Try autobody paint suppliers, it is a type of paint thinner. Just make sure that you wear a respirator when handling it. While it smells very sweet, it kills brain cells rather quickly.

Cheers,
Sean

additionally, you can melt celluloid in MEK (or acetone) and paint the resultant mixture onto celluloid to build up missing pieces, torn out chunks etc.

Celluloid dents can be easily removed, but you need to know what you are doing. I remove teeth marks from celluloid pens regularly, and when I am done normally you cannot see that there were marks there to begin with. But this only works when the base material is indented, and not torn out. Removing dents in celluloid is dangerous, probably moreso than solvent welding so I would rather not describe it in too much detail here.

I have used the melted celluloid/MEK mixture to build up missing parts from pens, weld barrels together, fill in personalizations. Its pretty amazing what you can do with that stuff really.

Cheers,
Sean

I just received a pair of razors in the mail yesterday. They both need a lot of work. I was going to have to throw out a pair of scales which were in prefect condition apart from being snapped in half. I will give the acetone repair a go.

A couple words.

• Ventilation.
• noignition source.
• Fire extinguisher.

Works great for a lot of things.

So working with celluloid and acetone in a small room with the window closed by candle light would be a bad idea.

Just as well I normally work in sunlight on my back veranda.

Mind you I splash around caustic soda on a daily basis at work so you can't wreck something twice

Quote:

---

Originally Posted by Pauly

Some things I have learned through trial and error in the last few days.

1) A No 2 or No 3 brush is the perfect applicator. Although a cheapie with synthetic bristles is plenty good enough, no need to buy a sable brush. You can get a pack of 5 or 6 brushes for $2 without any trouble.

2) Acetone will glue together a celluloid scale that has been snapped in half (this was the error part of 'trial and error'). Careful sanding and painting will make the join hardly noticeable, but not invisible. All you have to do is lightly paint each end with acetone and gently push the ends into place and then let them sit whilst supported for 15 minutes and you will have a solid join. Solid enough to re-pin a razor within 30 minutes of joining the two halves together if you are like me and have no patience.

3) Using a brush dipped in acetone to get underneath inlays as they start to lift is a very efficient way of removing metal inlays without damaging them.

4) You can glue inlays into new celluloid scales using acetone. Firstly you clean and shape the inlay for the new scales. Then liberally paint the back of the inlay with acetone. Quickly place the inlay into position on the new scales and lightly but firmly press the inlay against the scale. Use your fingernails or toothpicks to hold the inlay in position. After about 30 seconds the acetone will have melted the celluloid around the inlay and re-set. This leaves the inlay set into the side of the scales.
I would suggest that you use masking tape to mask off the area where you want to fit the inlay.
If you goof up you can use acetone to lift off the inlay, wait for the celluloid to dry out, sand the scar back with 1500+ sandpaper and try again. It's better not to goof up, but if you do it isn't the end of the world.

---

That will work very well with true celluloid, but other plastics are used in most recent razors. I believe ether will work the same way with at least some acrylic.

There are also specially made tubular drawing pens, for writing in a special plastic-etching ink on plastic film used in technical drawing. The solvent made for cleaning these will attack most plastics.

Has anybody ever tried methylene chloride?

Quote:

---

Originally Posted by Pauly

4) You can glue inlays into new celluloid scales using acetone. Firstly you clean and shape the inlay for the new scales. Then liberally paint the back of the inlay with acetone. Quickly place the inlay into position on the new scales and lightly but firmly press the inlay against the scale. Use your fingernails or toothpicks to hold the inlay in position. After about 30 seconds the acetone will have melted the celluloid around the inlay and re-set. This leaves the inlay set into the side of the scales.
I would suggest that you use masking tape to mask off the area where you want to fit the inlay.
If you goof up you can use acetone to lift off the inlay, wait for the celluloid to dry out, sand the scar back with 1500+ sandpaper and try again. It's better not to goof up, but if you do it isn't the end of the world.

---

Some more things I have learned about using acetone to set inlays into celluloid.
- Be liberal when applying celluloid to the back of the inlay. It is impossible to put too much acetone on the back of an inlay, but it is very possible to put not enough on.
- Put a small (emphasis on small) drop of acetone on where you are about to place the inlay. Any overspill will have a negative cosmetic effect. Whilst it can be sanded out it is better to not have to sand at all.
- Be sure to be firm when pushing the inlay into the celluloid. If you are going to make a mistake it is better to push too hard than not hard enough.

Quote:

---

Originally Posted by Pauly

Where does one get MEK?

---

Damn good question, took me a week to find over here.

Having read up a bit more on MEK, that is something I will personally leave alone.

If I was going to play with it I'd want a respirator and good eye protection.

I have full faith that SMG is right when he says that it will lead to a superior finish, it just is a product that you want to treat very seriously and you don't want to dabble with it.

Quote:

---

Originally Posted by Pauly

Having read up a bit more on MEK, that is something I will personally leave alone.

If I was going to play with it I'd want a respirator and good eye protection.

I have full faith that SMG is right when he says that it will lead to a superior finish, it just is a product that you want to treat very seriously and you don't want to dabble with it.

---

Eh, Methyl ethyl ketone isn't any more dangerous than acetone, or isopropyl alcohol. It's probably less hazardous than mineral spirits if I had to guess; petroleum distillates are pretty nasty. MEK, acetone, and isopropyl alcohol are similar in flamability, and exposure hazard. Sure, don't huff it, but I wouldn't huff acetone either. Also, a respirator that is designed for solvents must be used if that's the route you want to take. It must be a respirator, not a dust mask. Either that or a contained breathing apparatus. But really, just don't work in a closet or small room and you'll be okay. Moral: don't be scared, just be careful: ventilation, eye protection, and optionally latex gloves.

Credentials: Masters in Chemistry from Illinois State University (2010), Volatile Organics GC/MS Analyst

I would stay away from the latex gloves... Nitrile as well. MEX will typically eat right through them. If you are going to wear gloves get some rubber ones or butyl perhaps. You will lose dexterity but better protection. Also all of these chemicals are bad for you, they are just all bad for you in different ways.. Typically unless you use them daily for extended periods of time you have less of a concern about absorption through your hands and more nervous system damage through inhalation. I would advise respiratory protection and ther is a big difference in the many filters available if you are unsure ask a qualified person, not just someone at home depot. I have worked around these chemicals for years as a painter and I personally know people who have lost many years of their life due to improper PPE. I don't want to scare anyone either, just respect the seriousness of the chemicals that you are working with. As for where to buy MEK.... Try non-acetone nail polish remover, a paint store, or a hardware store or ask your friendly neighborhood painter... MEK is almost a universal solvent for many types of solvent based coatings. Also put the lid back on tight or all of these chemicals evaporate rapidly. Also lacquer thinner is a pretty hot solvent, it might work as well.

Quote:

---

Originally Posted by Worgus

... Typically unless you use them daily for extended periods of time you have less of a concern about absorption through your hands and more nervous system damage through inhalation. I would advise respiratory protection and ther is a big difference in the many filters available if you are unsure ask a qualified person, not just someone at home depot. I have worked around these chemicals for years as a painter and I personally know people who have lost many years of their life due to improper PPE. I don't want to scare anyone either, just respect the seriousness of the chemicals that you are working with....

---

+1 this. As to eating the latex gloves, don't know about that. Absorbing through them, definitely. I worked with methylene chloride for about a year, all day, 5 days a week. We rinsed all our glassware in methanol, then methylene chloride; even with super thick "solvent proof" gloves that cost an arm and a leg, the methylene chloride still gets through. Sure, MEK is probably sneaky stuff to work with, but methylene chloride is a nasty little monster. Even through those thick gloves, latex gloves, and kevlar cut resistant gloves, if they leaked AT ALL your hands would feel like they were on fire for a minute or two. Whew, I could talk chem and solvents all day long, if you want to play with a dangerous solvent try DMSO (dimethylsulfoxide); it slips into your skin, carrying any bacteria on your skin with it! Sorry for the long windedness, got off track.

TAKE HOME MESSAGE: 1. Safety glasses that WRAP OVER your eyes!!!! 2. ventilation, no need for a respirator if you're using proper ventilation 3. don't splash the stuff around. Pretty much it.

Quote:

---

Originally Posted by adbuett

+1 this. As to eating the latex gloves, don't know about that. Absorbing through them, definitely. I worked with methylene chloride for about a year, all day, 5 days a week. We rinsed all our glassware in methanol, then methylene chloride; even with super thick "solvent proof" gloves that cost an arm and a leg, the methylene chloride still gets through. Sure, MEK is probably sneaky stuff to work with, but methylene chloride is a nasty little monster. Even through those thick gloves, latex gloves, and kevlar cut resistant gloves, if they leaked AT ALL your hands would feel like they were on fire for a minute or two. Whew, I could talk chem and solvents all day long, if you want to play with a dangerous solvent try DMSO (dimethylsulfoxide); it slips into your skin, carrying any bacteria on your skin with it! Sorry for the long windedness, got off track.

TAKE HOME MESSAGE: 1. Safety glasses that WRAP OVER your eyes!!!! 2. ventilation, no need for a respirator if you're using proper ventilation 3. don't splash the stuff around. Pretty much it.

---

Yep, spent a lot of time in the last few weeks with paint thinner containing methylene chloride. Kept using progressively thicker gloves before I found a pair it wouldn't absorb through....

Lots of fun when I spilled some, then accidentally knelt in it to get my brush under a ledge...

Quote:

---

Originally Posted by adbuett

Eh, Methyl ethyl ketone isn't any more dangerous than acetone, or isopropyl alcohol. It's probably less hazardous than mineral spirits if I had to guess; petroleum distillates are pretty nasty. MEK, acetone, and isopropyl alcohol are similar in flamability, and exposure hazard. Sure, don't huff it, but I wouldn't huff acetone either. Also, a respirator that is designed for solvents must be used if that's the route you want to take. It must be a respirator, not a dust mask. Either that or a contained breathing apparatus. But really, just don't work in a closet or small room and you'll be okay. Moral: don't be scared, just be careful: ventilation, eye protection, and optionally latex gloves.

Credentials: Masters in Chemistry from Illinois State University (2010), Volatile Organics GC/MS Analyst

---

I've studied toxicology as part of a Masters of Workplace Health and Safety, which I discontinued when I changed careers. Also I have 18 years experience in industrial personal injury insurance so I have seen plenty of examples of chemical poisoning.

After reading the MSDS and doing some research I would use a respirator when handling MEK (and yes I know that MSDSs are written by professional worrywarts). Then again I may be confusing the appropriate safety standards for handling industrial quantities of MEK and what is appropriate for a hobbyist.

I would counsel against using gloves whilst handling razors. you can easily protect against skin exposure by using the appropriate tools (eg paintbrush and toothpick).

OK so I am trying to repair a set of scales that broke near the pin in a unppining accident. I have MEK I bought from Lowe's after reading here that it should work better and stronger then Acetone and I have tried "painting" it on the scales where they broke and holding them together but nothing. The stuff evaporates almost as soon as I put it on and even when I hold the scales together and paint the breaks while holding them they still do not stick and do not even start to melt at all and I am not sure what I am doing wrong. The scales are black celluloid off a morley and son's and say clover brand on them so I would realy like to save them and yes I am making a brass backing for the scales as well since they broke near the pin. The picture below is the same type of scales on another morley that isnt broke for reference. My camera died so I dont have a way to take pics of the broken scales right now but it was a twin set to the one in the picture. Please HELP!

Attachment 75221

Hi,

Firstly I am not an expert on this field, just an enthusiastic beginner.

My first question:
Are you sure the scales are celluloid?
My experience has been that acetone reacts very quickly and vigorously with celluloid. You should be able to see the melt occurring with just the smallest drop of acetone.
They may be another early plastic like bakelite or even vulcanised rubber.

Second question:
How old are the scales?
I collect razors mainly from the 20s and 30s, which is when the process for making celluloid had stabilised. One of the earlier production methods may not used the same processes and thus make MEK/acetone inappropriate.

I think they must be bakelite then cause the acetone and MEK both have no effect on the scales. Ill try some epoxy once I finish the brass baking for them. Thanks Again for the help.

Quote:

---

Originally Posted by WarmShave86

I think they must be bakelite then cause the acetone and MEK both have no effect on the scales. Ill try some epoxy once I finish the brass baking for them. Thanks Again for the help.

---

rub the scales until they get warm between your hands. If they smell like sulphur then they are bakelite or hard rubber. If they were celluloid, the MEK and Acetone would have definitely reacted with them.

Cheers,
Sean