A very popular adhesive/glue/cement used by the old timers in the early days of radio is celluloid cement. Goes way back -- late 1800's I think. Duco brand (made by Devon) was common. Still available today! In small one-ounce tubes. But if you makes yer own (very cheap), you can make it in different thicknesses for different purposes. I made some in a quart jar for coating coils. Thin enough for most of it to drip off, leaving a thin coat to hold the wire together. Cut up four Ping Pong ball into small pieces to make them easier to dissolve in the acetone. You don't have to cut them up if you don't want to; they will dissolve anyway. Ping Pong balls are made of celluloid, a type of nitrocellulose with a little camphor added (not fully nitrated; fully nitrated it'll be guncotton). You might start with a half ounce of acetone per ball, for thick glue, maybe go up to 2 ounces per ball. I just add acetone until I get the consistency I want. Just add the acetone and let sit overnight. I discovered the acetone will diffuse evenly throughout the celluloid. I reckon you could color it, but I haven't tried that. Celluloid glue is hard, waterproof; can be scraped, sanded, filed, etc. It's good for ceramics (break your wife's knick-knack and repair/hide the evidence). Will stick to glass (good for tube bases) and metal besides wood. Will glue leather; was used along with stitches to make boot soles. I think you can still buy it for that too.

That sounds like a very useful adhesive. For sure, I'll try making some. Thanks for posting it. I could imagine it being used, also, as a repair for bakelite cracks when you are going to paint the cabinet.

Ping Pong ball and old piano keytop white celluloid work & is easy to work with, but are extremely flammable; don't get a lit match, torch, or hot cigarette remains near them; it will quickly burst into flames and one cannot get it extinguished without using a good extringuisher or water dowsing. Piano techs used to use this homemade, thinned celluloid in acetone (made from the old white celluloid piano keytops, which were substituted for real ivory on "economy" pianos & reed organs thru about 1930) for "juicing" piano hammers to harden them during voicing. But nowadays, piano supply houses do not sell used celluloid because it is extremely flammable. I think that accordions may still use celluloid casework, but one shouldn't play accordion and smoke at the same time.

So, celluloid doesn't stand up to heat, sparks, or open flames; and is a definite risk if anyone in the house smokes.

Fred

>So, celluloid doesn't stand up to heat, sparks, or open flames; and is a definite risk if anyone in the house smokes.

Is that also true after it completely cures?

And if you dont want the hassle of making it then buy it here and elsewhere. If the link doesnt work its GC Electronics Q Dope part # 10-3704. IMO, the only formulation to use on coils.

http://www.jameco.com/webapp/wcs/stores ... Id=615195&

Carl

Hello,


Celluloid is a fire risk as a thin film in a movie projector
or in other cases of thin films.
A glob of that glue is not so easily ignited.
Cure: Celluloid does not "cure" ! It just dries physically
and that is it.
Most important: There is no need to make or buy such a
celluloid glue! Any standard modern home/bureau glue
is as good as celluloid!
Georg

The GC brand Q-dope I have on the shelf (same Part # as mentioned above) is listed as having a polystyrene base with a toluene (toluol) thinner (if a thinner/reducer is needed). So I think it would be quite safe after curing. The problem with old fashioned celluloid (as found in old ping-pong balls, movie film, white piano key covers ( ~40mils thick), some Model T windshields, is it will flame if heated. Power buffing piano celluloid keycovers or accordion cases doesn't work because the heat buildup from the cloth wheel causes flaming which is difficult to extinguish. Power sanding celluloid also creates flames.

Fred

Celluloid has up to 25% camphor added to stabilize it. other agents are added to make it less flammable. About flammability; Experiment for yourself. Get some ping-pong balls and throw spark at them. The stuff burns well, but is far from explosive. It's not fully nitrated like guncotton is anyway. It's quite safe. Acetone burns damn good, though. But I can see how a finely divided powder, from polishing and sanding, with it's high surface area, can be explosive. Even wheat flour is explosive!
The stuff is still used in ping-poing balls and guitar picks because of it's properties. It is extremely rigid and hard in thin films, and springy, thus makes a light bouncy ball.
Works good for coils since it isn't subject to much RF heating. Low loss.
The reason I made celluloid adhesive was my desire to replicate vintage homebrew receivers, using available materials, as much as possible, available during the Depression. I want to experiment with the same spirit of ingenuity as my grandfather did when he built radio sets in the '30's.
By the way, I remember reading that early billiard balls (early subs for ivory that is) were sometimes over nitrated and would blow up!

The camphor is added to plasticize the nitrocellulose.
After mixing (with some acetone added sometimes) the
Celluloid is a bulky mass worked out (dried) as chips
of some millimeters thicknes. That is what reduces the
ignitibility! Nitrocellulose is dangerous due its fluffy consistence,
it looks almost like it looks before the cellulose/linters is nitrated:
a fluffy thing, similar as the cellulose in a diaper.
Nitrocellulose is shipped either moistened with some solvents
(to have some conductivity, to avoid static electricity)
or plasticized with some phthalic esters. This plasticized NC
(procuct of ICI) is similar to celluloid, i. e. safe to handle.
But neither nitocellulose for guns nor that for celluloid (low MW)
is "explosive"! It will ignite and burn rather quick, but no
explosion, if not enclosed in a gun.
The story of exploding billiard balls is nonsense.
Georg
PS
Nitrocellulose laquers were the most important laquers
for furniture and cars from 20ties up to 50ties.
The same low MW NC used for making celluloid was
used for the "universal" glue of that times.
No problem with fire exept when working with the fluffy NC!
The main problem was the combination of Celluloid
and cinema projectors, where carbon arcs with som Kilowatts
burned!
All this hearsay gossip about dangerous celluloid is really
disgusting.

Q Dope is also period correct for the early 30's and later and is arguably the best for RF coils. I have a few unopened bottles of the GC 10-3704 as I havent gone thru the case of the 50's Millen version yet. James Millen is credited as the inventor when he was the Chief Engineer at National Radio and its listed in their 1934 catalog. Toulene wasnt developed until much later so the earlier solvent was likely lacquer thinner.

Carl

Hello Georg; don't be too hasty in your dismissal of exploding billiard balls.
There is a fellow on the forums that recently said he's a chemist and that he's entertained by some chemistry lessons he's read on the se forums. He also implied (don't remember exactly what he said) that what was said is not far off the mark. Let me see if I can entertain him some more! I'm speaking from memory so I might be screwin' up, so I hope the chemist (don't remember the name) will come on board and help me out.
The propellant and explosive nitrocellulose/guncotton is the tri-nitrate cellulose nitrate, an ester. The cellulose nitrate used in celluloid has a nitration, if I remember correctly, of 11% and is di, not tri. Dinitrate that is. The trinitrate is about 14%. There is a mononitrate, somewhere about half of the nitration of the dinitrate. Three forms because the cellulose has three hydroxyl groups on it, which can be replaced by 1-3 nitrate groups. I don't know what the mono version is good for, but the di version is our thermoplastic that was so useful in the past. It's still sold (Duco) so there are people using it to this day.
I would like to add a little background about myself so folks in this forum will know where I'm commin' from. I was raised by my grandfather, who was had a radio shop from the late 30's to the sixties. Later he sold and repaired "coin operated equipment". i.e., vending machines. He traveled throughout West and South Texas making sales for All Coin Equipment Co. out of San Antonio , Texas. He said he heard old stories here and there from old-timers about the old pool (billiards) balls that would pop. He said he had one at one time. It had a divot out of it. The balls were filled with some kind of filler and were only coated with celluloid. What was supposed to be happening with these early balls was that it would emit a loud bang, and a piece would then be found missing rendering the ball worthless.
When I was a teenager in the 70's I made a little money working on vending machine locks, re-tipping cues (billiard or pool sticks) and re-felting pool tables. There was pretty good money in the pool tables and juke boxes. I recall one place my father had called the "Dog House". A beer joint. Same as a pub. We would "rob" the machines every Friday. It would cost two quarters, fifty cents a game, back then. Texas law required that the money be split exactly 50-50 with the pub owner. But my father owned the machines 100% and owned the Dog House with a partner, so he got more money. The place coughed up about $400.00 a week, and my grandfather got $200 which was half the machine take, and half of the remainder of the second $200.00. So that was about $1200 a month, from just the pool tables, and at just one location, back in the '70's. Pretty good money.
I joined the military and was in for 22 years. I was in Panama from '79-'81. My job was to provide close air support to ground forces, so even though I was in the Air Force I worked with the Army out of Fort Clayton. The Army commander started up a rifle competition called the Commanders Annual Gold Cup Something or another; it was a long winded name. The arsenal folks went through all the rifle qualifying records of everyone in the military there at the time and picked the top ten from each Service. I was number 8 for the AF. The Air Force was all lumped together for the picks, as well as the Navy, but the Army was divided into units as well as the Panamanian Defense Force. Anyway, I fell in with the Armory bunch and I hung around there a lot. The guys experimented (played) with various ordinance. I learned a lot from those guys. Later I became a firearm collector and got my FFL (gun dealer's license). I don't mess with guns very much nowadays, mostly vintage radio.
About cellulose nitrate again; it is considered a propellant, but it can detonate. Propellants, as used in a firearm burn. Burn fast. Called conflagration, the flame passes on from one grain of "powder" to the next, and the grain burns from the outside in. The grain can be given various shapes which may include holes so that the grain burns at a constant rate, or burns faster or slower at it's consumed. Cellulose nitrate is the basis of smokeless powder that began to replace black powder in the 1890's. If the smokeless is all cellulose nitrate, it's called a single base powder. If some nitroglycerine is added, it's a double base powder. It's softened with ether alcohol and extruded in a die. If you open up a new can of powder, you can smell ether.
Under special circumstances cellulose nitrate can detonate. Even black powder, finely divided, can detonate if struck with a hammer. Detonation is a different kind of burning. Instead of flame hopping from grain to grain, a shock wave passes through the material. The shock wave compresses the explosive, and the explosive material breaks down as the shock front passes through, which is very very fast. So fast that containment is not necessary as with conflagration, in which the material burns slow enough that it must be contained in a vessel until the vessel burst suddenly from the pressure, or a bullet is forced through a gun barrel. There is a strange and rare phenomenon in which light loads of powder are loaded in a firearm cartridge, with a lot of empty space in the cartridge, and the powder can detonate. Even the load is small, it can blow up the gun's chamber. I don't know if anyone ever figured out how that can happen, but it was a mystery that can happen.
I can certainly see how a billiard ball covered with cellulose nitrate that has been a little too well nitrated could have a localized area of detonation at the impact point. Quality control was iffy back in them days, and in more modern times we've found how to treat the material to make it less flammable and less prone to disintegration over time. The camphor added to dinitrate is both a plastisizer and a stabilizer. There are other things added too, but I can't say what.

Please guys. It seems this topic is now drifting off-topic.

This is Hints & Kinks. Keep it concise and to the point.

Thanks.

Chuck

I haven't made any but I understand that you can also dissolve styrofoam in solvent too to make glue or coating. That's polystyrene. Is that what's in Q dope?

Thats about it. Ive made Q Dope many decades ago from thin polystyrene rod and lacquer thinner; this was long before styrofoam!

Carl

On the topic of bakelite- I have 4 feet made of bakelite on the bass of my accordion. One of these cracked. I glued it back together, but you can still see the cracks. Can I sand it down? Can it be buffed then? Or can I make it glossy by rubbing acetone on it? Thanks, Steve

Bakelite is a Thermoset plastic and won't melt, and won't dissolve in any solvents that I know of. Some folks repair broken bakelite by grinding some up into a powder (bakelite of similar color) and mixing it with glue then applying. Only thing I can think of for you to do would be to paint the feet an acceptable color. Bakelite radios were commonly painted. Maybe you should start a new thread in Repairs so as to attract some attention to the issue of repairing bakelite.

Before you consider celluloid to be the miracle material, read the following short item:

http://www.philcorepairbench.com/tips/svctip36.htm

The celluloid appears to release nitric acid which eats into copper and has caused coils to go open.

Dear Plasteraccordion- I have had good luck mixing Devcon 2 hour epoxy with Bakelite dust and then clamping the broken piece. My .02-Gearhead

I couldn't find that Q-Dope coil varnish on the Jameco site. Any other links or is it no longer available.
Don Black.

Don- I would think that it is still available, but it may be going by some other name nowadays. But here in the good old US of A, a lot of outlets quit handling products like that simply because someone, somewhere, sometime, is going to complain that they are cancer causing or some other environmentally thing will be said about them.
Curt