This is topic Film cement joins in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Glen Rich (Member # 1150) on 03-12-2002, 05:17 PM:
With the introduction of polyester(read crap)based film,I've found that most,if not all of the second hand prints that we've received from the U.S. are still being repaired with film cement.
I noted that the manufacturer recommended using splicing tape,and not film cement,(just before I sliced my left thumb open with it for the first time).Is it required practice,force of habit,or am I just getting lucky.
I find that I spend way to much time either removing the cement joins,or taping over them if trying to get the print on screen 10 minutes ago.
The last time that I actually used film cement was during a required part of training,nearly 20 years ago.
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Posted by Steve Guttag (Member # 268) on 03-12-2002, 06:31 PM:
Film cement won't work on polyester, period. What you may be seeing are ultrasonic splices. They look quite similar (between perf overlap) but their durability is quite different. An ultrasonic splice is very strong and there is no need for removal unless it happens in the middle of the frame and causes the picture to look too ugly. Steve
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"Old projectionists never die, they just changeover!"
Posted by Ken Layton (Member # 133) on 03-12-2002, 07:05 PM:
Steve is quite right. Polyester film stock CANNOT be spliced with film cement. Only tape or ultrasonic splices work.
Posted by Paul G. Thompson (Member # 655) on 03-12-2002, 08:52 PM:
Steve is correct. Don't even waste your time to try it. It simply will not work.
Posted by Mark Gulbrandsen (Member # 72) on 03-13-2002, 12:38 AM:
Yea, If you do atempt trying to do it at all Paul will throw that hot dog right out through your Monitor screen! The bad thing there is that they're real greasy.
Mark @ GTS
Posted by Stan Gunn (Member # 554) on 03-13-2002, 12:53 AM:
A cement splice on acetate, if done correctly is as good as an ultra sonic splice on poly.
Anyone trying to join poly with cement must have not been takeing notice of the changes in the industry over the past few years. 
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Posted by Joe Redifer (Member # 3) on 03-13-2002, 01:06 AM:
I also want to jump on the "Steve is correct" bandwagon. You can never have too many people telling you the same thing. Cement splices don't work on polyester film.
Posted by Leo Enticknap (Member # 534) on 03-13-2002, 02:38 AM:
I'd like to jump on the 'Stan is correct' bandwagon, and furthermore add that on acetate, properly made cement joins are better than tape joins in every possible way. Nothing is visible on the screen, digital sound is not affected (only two Dolby data blocks are affected, and I believe the system can survive four corrupted ones without dropping to analogue) and the join will last longer than any splicing tape before drying out. Furthermore, when it has dried out, if you remake the join with care, gently removing the dried cement and cleaning the area of film from which the emulsion has been scraped off, the join can be remade without any loss of frames. OK some sorts of tape are better than others when it comes to leaving deposits, but they all will if they're left on the film long enough.
Posted by Pete Naples (Member # 761) on 03-13-2002, 05:13 AM:
I used to see a lot of ultrasonic splices in first run films, I don't recall ever seeing one that wasn't a; smack in the middle of a frame. b; out of rack or c; had a wildy colourful 'splat' all around it. I assume these are done by the lab, if they run out of stock mid-print? Needless to say they all had enormous gaps in the sound track, and needless to say they were all cut out and replaced with a good tape join.I too haven't seen or made a cement join in years. I was taught to make them in training, never used them on 35mm, have used them on 16mm and 8mm though.
BTW Steve is correct, whilst I've never personally tried, everything I've ever read says that cement won't stick poly based film.
Posted by Leo Enticknap (Member # 534) on 03-13-2002, 07:25 AM:
I'd have to go back to my archive training notes to find out the chemistry of this, but I seem to remember that the reason why has to do with the 'subbing layer' (which is camphor in the case of nitrate and something else in the case of acetate) which binds the emulsion to the base. You scrape off the emulsion to expose this layer, and that is what the cement reacts with to produce an adhesive effect. Polyester doesn't have a subbing layer, which is why it won't work. I'm sure John P could explain the reasons for this far better than I can.The International Federation of Film Archives suggests different chemical formulations for cement to join nitrate to nitrate, nitrate to acetate and acetate to acetate. We take the wussy option and buy them ready-made...
Posted by John Pytlak (Member # 331) on 03-13-2002, 07:37 AM:
Some information on splicing:
http://www.kodak.com/country/US/en/motion/support/technical/ultrasonic.shtml
http://www.kodak.com/US/en/motion/support/technical/splice.shtml
http://www.kodak.com/US/en/motion/support/technical/hand.shtml
http://www.kodak.com/country/US/en/motion/support/h1/baseP.shtml
http://www.acvl.org/4c.htm Cement (solvent) splices do NOT work on polyester (ESTAR) base films because polyester is impervious to most solvents. Cellulose triacetate and cellulose nitrate films can be cement (solvent) spliced because the solvents actually dissolve the film support to make the weld.
Here is the US MSDS for Kodak Professional Film Cement:
MSDS for Kodak Professional Film Cement
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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
Posted by Leo Enticknap (Member # 534) on 03-13-2002, 07:47 AM:
Article by Joao Oliviera (film preservation scientist with the British Film Institute), on acetate decomposition and the implications of this for (amongst other issues) splicing...
Posted by Bernard Tonks (Member # 809) on 03-13-2002, 11:38 AM:
In my trainee days, you were also taught how to make hand made cement splices which was easy to do with nitrate stock but not so easy with safety stock. Most film splicers in the UK were the one sprocket hole overlap type which whilst made a perfect splice you could always see a very faint line at the bottom of the screen on making up from head out. When I took my first chief’s job, I bought my own splicer, which I think was known as the intersprocket type on the frame line but suitable for release prints. As Leo said, nothing is visible on the screen.
Posted by Gerard S. Cohen (Member # 994) on 03-13-2002, 09:29 PM:
The Neumade/Griswold wet splicers were sold for negative or positive
splicing, the difference being in the width of the anvil bar which
determined the amount of overlap. The wider bar and overlap was used in projection booths and the narrow one for negative cutting. When the bar became worn, two setscrews could be loosened, and the
bar inverted, bringing a new, square and sharp-edged surface into play. A small cast iron holder contained a scraper, the surfaces of
which could also be rotated when worn, and a stiff wire brush. This
handy tool was easily lost unless attached to the splicer with a beaded chain or length of monofilament fishing line. Usually this tool was replaced by single edged razor blades, conveniently tucked
under the manufacturer's brass label on the front of the splicer.
I have a 35mm model containing two "D" cell batteries that illuminated
a 3V bulb under a convex lens, providing light for examining film
and splice in dimly lit projection booths.
Splicing cement [solvent] contained film stock disolved in acetone*,
available in thin or thick consistencies according to the user's preference. Neumade made a black, round cast iron bottle holder, with a wood, aluminum and brass pen-like applicator. A fancy gift set
on a white ceramic base was available that held bottles of water, cement and blooping ink, with a grooved tray to hold scrapers and applicators. (Photo in the 1934 Neumade catalog.)
Neumade/Griswold splicers were originally made in New York City and upstate, and are very common today, sold as nostalgic collectables for about $8 to $10. I've heard of them being made into lamps and
bookends. The 16mm model is still used by students and film collectors, and is similar to the 35mm model, but half its size and weight.* See John Pytlak's link to Kodak Professional Film Cement (above) for a complete list of ingredients, formulae and caveats.
Posted by Stan Gunn (Member # 554) on 03-15-2002, 10:28 PM:
Hi Gerard.
I have a couple of Griswold R2 splicers, what would be the chances of obtaining a scraper for one?
I intend to repaint and re nickle them for display purposes, it would be nice to have a scraper to complete them.------------------
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Posted by Jerry Chase (Member # 660) on 03-15-2002, 10:47 PM:
Pish. The only scraper any real projectionist ever used was a single edged razor blade. "Gem?" somebody help me out here. The only way to make a decent splice was to spit on the index finger, wipe it on the emulsion, wait a few seconds, then wipe it off with the "preferably slightly dull" razor blade, then make the splice.
Posted by Stan Gunn (Member # 554) on 03-15-2002, 11:17 PM:
Jerry.Didnt I see you under the bed?
The O.H.A.S. has banned the practice of spitting in the Bio box / booth
as all the spittoons and sand buckets have now been removed, this means that all cigar butts must now be disposed of via the exhaust ducting, and spittle confined to ones own mouth.
It is however allowed to discharge a stream of spittle at nitrate film should your cigar ignite the film.
Extreme care should be used however in not allowing spittle to splash onto your asistant.
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KALEE FOREVER. CARBON ARC, THE ONLY LIGHT FOR THE STARS!
ALL PARTS FOR VICTOR AND KALART VICTOR 16MM PROJECTORS.SERVICE TO 35 AND 16MM PROJECTION EQUIPMENT.
35MM sprockets made to order.
Posted by Paul G. Thompson (Member # 655) on 03-16-2002, 12:41 AM:
When I was in Japan in a long time ago, the Japaneze showed me how to make a perfect splice with only a pair of scissors and a small stick about the size of a "Q" tip.
Posted by Gerard S. Cohen (Member # 994) on 03-16-2002, 05:04 PM:
Stan,
The scrapers are hard to find, unless you can buy one from Wolk or some other supplier that has old Neumade supplies in a warehouse drawer. You might ask Bob Maar--I think he's connected with Neumade.
Scrapers are listed in the old catalogs from the 1930's. Incidentally, the rounded shiny piece of bar stock screwed parallel to the right of the anvil bar, is a guide on which the grooved scraper
travels as you scrape back and forth. (Most users never realized why it was there.)
As for refinishing, the original black finish was baked on and impervious to film cement or solvent cleaner. The factory used the same process in refinishing splicers sent to them. But some projectionists repainted them with aluminum paint or black enamel
which looked crappy and softened in use. Every last part, from the spring clips, cutters and screws, were available from the parts catalog, and projectionists used to order them and keep spares in little manila envelopes. If you have a chance to visit an old booth
in a theatre undergoing renovation or demolition, look for these envelopes on shelves in the rewind room or in steel drawers.
Keeping such a simple cast-iron splicer in top shape was a matter of pride to projectionists before tape splicers came into use.
Posted by System Notices (Member # 2357) on 10-08-2004, 06:29 PM:
It has been 937 days since the last post.
Posted by John Strunack (Member # 1938) on 10-08-2004, 06:29 PM:
I realize that ranting over cement (ultrasonic ) lab splices to film companies is like beating a dead horse, But lately we have been getting a large rash of lab splice in our theater. Taxi had 6 lab splices Cellular had 3 lab splices Friday night lights 1 lab splice and ladder-49 had 2 lab splices. Since we are a small independent theater and low payroll and budget I try to get most of the lab splices out as I can on build up night. The big problem we are experiencing here with the lab splices is causes the picture to jump out of frame in the projector and sometimes get crooked in the gate causing the film to get stretched. I have checked everything in the projector including adjusting pad rollers and they still cause a problem. I been in the movie industry as both projectionist and theater technician for 10 years and never came across problems like this before. I also have advised our backup theater technician who has been in the field for 25 years and he is stumped. Can anyone out there that may be assistance in what is causing the lab splices to go crazy in our projectors. Any feedback would be greatly appreciated.
We are running Simplex 1014 Xl projectors 4 of them have gate bands and 3 have the straight gate
Is jumps on both types of gates.
Thanks John ![[Roll Eyes]](rolleyes.gif)
Posted by Brad Miller (Member # 2) on 10-08-2004, 06:32 PM:
You have some serious issues with your trap alignment if an ultrasonic splice is causing the film to jump the track. If your tech can't fix it, it's time to get one that can.
Posted by John Pytlak (Member # 331) on 10-08-2004, 06:39 PM:
Ultrasonic lab splices may sometimes be ugly (especially if not on the frameline), but they are usually reliable. But typically, there are "ears" that protrude over the edge of the film a bit, made up of excess polyester from the weld. Maybe your gates are set a bit tight, so these "hang up" in the gate? If you decide to leave the splice in the print, carefully trim the edges of the splice overlap smooth with the edge of the film.
If the labs are using 6000-foot raw stock rolls, on AVERAGE, you will have one splice every three or four reels. Here is the guideline from the Association of Cinema and Video Laboratories:
http://www.acvl.org/manual/4c.htm
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