Sticky shed, shot pinch roller, or both?

Chris Shaeffer

Chris Shaeffer

Peavey ROCKS!!!!!!!!!!!!!
This is my trial by fire, I suppose. :)

A few things have happened.

1) My pinch roller has always seemed very dirty. I've cleaned it regularly, but not thoroughly every time I cleaned the heads. The Q-tip always came off BLACK.

2) I got some Ampex 456 off ebay- which I now realize must be pretty old to still be labeled Ampex. I got a good enough deal that it was worth it for the nice reels alone, but I wonder if these tapes are going to have sticky shed? I ran one of them for maybe 45 minutes total so far...

3) I figured I'd see how dirty it was and clean it a little more. Almost immediately I noticed that a dark brown (probably oxide) layer came off fairly easily to reveal a nice black rubber underneath. Seemed like the guy before me must have rarely cleaned it.

4) Whoa. Its really dirty- and now I'm made a clean patch. Better clean it all. Cleaned it all off- looks great!

5) Threw the Ampex tape back on a few hours later to continue working on a new tune and noticed a weird thrumming noise- turned out to be the tape getting stuck and unstuck on the pinch roller. Damn thing was sticky as hell. Now I know why the guy before me didn't clean it... the crap stuck to it was keeping the roller from sticking to the tape... or...

6) Sticky shed?! I checked the heads and they're spotless. Would the heads be gummed up too if this was sticky shed?

7) I tried cleaning it again (which made it worse) let it "dry" really well (which seemed to make it better), and sacrificed a minute of tape and played it through a few times. It stopped sticking after a few plays and now works almost as well as it did before I cleaned it- but its still a little sticky to the touch.

So I've already ordered a new pinch roller from Tascam (~$40 shipped) and the rubber cleaner that Ghost recommends... I'm confident I'll be able to get back up and running one way or another. I'm not going to use it till the new parts come in, I think. Would the (now) mildly sticky pinch roller cause damage to the tape?

Any insight or advice on what happened? Are there other ways I can identify bad tape than putting it on the machine and praying? Is there any way I can determine if this was sticky shed, a shot roller, or both?

Thanks,
Chris
 
One way to check for sticky shed is to rub the oxide side of the tape with a Q-Tip. if you create a shiny spot, then it's likely sticky shed. But by your description it does indeed sound like sticky shed. You should stop using that tape. It's possible that there was a larger build-up of residue on the pinch roller than you could detect by sight. Those things can get pretty dirty. But make sure to clean the entire tape path including rollers and tape guides/lifters.
 
Chris Shaeffer said:
6) Sticky shed?! I checked the heads and they're spotless. Would the heads be gummed up too if this was sticky shed?
Click to expand...
From my (very) limited experience with sticky shed I'd expect the entire tape path - guides etc as well as heads - to have noticable oxide buildup. So it sounds more like pinch roller, especially if it seems sticky after a clean. I think you're on the right track.
 
As for the tape type and age, there was an extremely useful post about that a few months ago. IIRC the following rule of thumb applies:

Quantegy - no problems
Ampex with logo at the bottom of the front cover - should be OK
Ampex with logo in the middle of the front cover - bad

*EDIT* if you can get some tape on a hub, you can use the spool from some dodgy tape, either by taking the flanges off or by spooling it over (using a single flange to act as a pancake platter).
 
yeah if your pinch roller is coming off BLACK that is bad. a little grey, maybe. but if the pinch roller is sticky that is BAD. that crap is TOUGH to get off of your tape path. dont run any tape with that pinch roller. the tape is probably shot now too you may as well throw it out. get new tape and a new pinch roller and scrub the heads and everything else.
 
Thanks, all.

Well, that answers a couple questions.

First, the "new" Ampex tape did not get a shiney spot when rubbed with the Q-tip. The tape that came with the machine did, however. Guess I know which tape to stop using...

"Ampex with logo in the middle of the front cover - bad"

....all of it. (sigh) Oh, well. I do have 1 reel of unused Quantegy 456 that came with the machine. And I'll be ordering

Second, I cleaned the rest of the tape path and there was almost no residue at all- the Q-tip came off almost clean. There was a little dirt on the tape guides, but nothing else. At all. Looking at all the metal in the tape path its shiney and smooth. Have I lucked out... or was it just bad rubber on the pinch roller?

Or do I just not know how to clean the thing? I'm assuming I shouldn't be scrubbing like crazy. Or should I be?

Thanks,
Chris
 
Chris,

Is there any way for you to determine what material the pinch roller is made of and the RMS finish? Rubber compounds can be nasty especially if pitted or rough.

I have a couple tape units and I've never had a problem with the pinch rollers.

I'm curious.
 
60's Guy,

Well, I have no idea if the rubber or the whole roller has been replaced in the past so I can't really assume that its an original or the standard Tascam part.

If the miracle cleaner that Ghost recommends doesn't cure it, I'll probably send it off to the guy who replaces the rubber and I'll ask him if he has any insight on it. If I get any usefull info about it I'll post it back here and PM you.

And what is the RMS finish?

Thanks,
Chris
 
Chris Shaeffer said:
60's Guy,

Well, I have no idea if the rubber or the whole roller has been replaced in the past so I can't really assume that its an original or the standard Tascam part.

If the miracle cleaner that Ghost recommends doesn't cure it, I'll probably send it off to the guy who replaces the rubber and I'll ask him if he has any insight on it. If I get any usefull info about it I'll post it back here and PM you.

And what is the RMS finish?

Thanks,
Chris
Click to expand...
Hi Chris,

First off...I listened your latest. Great stuff, man!

OK....RMS?

RMS stands for Root Mean Square not Roughness Measurement System as is commonly thought, but it is relative to the roughness of a surface.

I work within an industry that provides anodized aluminum plating for the printing industry. Within our manufacturing process (machinery), we have many industrial rolls that are covered with synthetic materials because they are subjected to a wet process involving sulfuric acids and other liquids that attack rollers leaving black streak marks or contamination of the roller coverings. Ours is a severe environment as compared to "sticky shed", but I found this thread interesting because I've had some experience with hostile contaminants and I also have many old tapes that date back to the 1950s that my dad made. It was only within the past 5 years or so that those tapes came into my possession. I've played them on multiple occassion and I did notice a problem with them which required a fairly frequent gentle cleaning of heads (in machine direction travel only...not up and down scrubbing), but I noticed minimal affect to the pinch rollers.

I guess I have some further investigating to do myself in determining the pinch roller material on my tape unit.

As to RMS.....

Below is a good link for general information.

http://www.mfg.mtu.edu/cyberman/quality/sfinish/terminology.html
 
Chris Shaeffer said:
I'm assuming I shouldn't be scrubbing like crazy. Or should I be?
Click to expand...

If junk comes off keep scrubbing. get in all the little cracks and even behind the parts that aren't necessarily touching the tape because they build up too.
 
Cool. That's what I was doing.

The entire tape path- except the roller, which is now very clean but very sticky- is clean. I'm still not sure that it was sticky shed- at least not when I've been using the machine. I received the heads clean and they are still spotless. Perhaps I'm dealing with the leftovers of a sticky shed episode before I got the machine.

Now I'll *patiently* wait for my new pinch roller to arrive from Tascam...

60's Guy, I checked the manual and, at least as far as I could tell before I came up for air, it doesn't specify what rubber is used on the pinch roller. All I found out is that its the same pinch roller as the model 38. And thanks for the Kudos! So far I'm happy enough with my work- though I certainly hope I get better with the tape machine. Its still a bit new and I'm sure I'm not getting out of it what I will be able to with more experience.

Chris
 
dude a sticky pinch roller is bad. just forget about it and get a new one. its not shed. the rubber is corroding. most likely it can't be cleaned.
 
Yeah. First thing I did was order a new one from Tascam. The rest is just using the situation as on opportunity to learn. Gotta have something to do while waiting....waiting...waiting... for it to get here.

-Chris
 
jpmorris said:
As for the tape type and age, there was an extremely useful post about that a few months ago. IIRC the following rule of thumb applies:

Quantegy - no problems
Ampex with logo at the bottom of the front cover - should be OK
Ampex with logo in the middle of the front cover - bad

*EDIT* if you can get some tape on a hub, you can use the spool from some dodgy tape, either by taking the flanges off or by spooling it over (using a single flange to act as a pancake platter).
Click to expand...


what about AMPEX with the logo on the top right hand side of the front cover?
it is

AMPEX 291 "audio visual tape" :confused:
i could not find a single resource about this brand of tape
 
just saw this thread resurface. if you need a quick fix, put some tape (electrical or masking i guess) over it.
 
BOJAX said:
what about AMPEX with the logo on the top right hand side of the front cover?
it is

AMPEX 291 "audio visual tape" :confused:
i could not find a single resource about this brand of tape
Click to expand...

Does it have the date code on the side of the box?
For Ampex it's like 92115, which IIRC means day 115 of 1992.

The only reference to that tape I have found so far is this:
http://home.earthlink.net/~cathgar/productionnotes.htm
..which is emphatically NOT GOOD.
 
no date code
i saw that site too (they are a great band btw) but i'm not sure it's the same exact tape
I had bought them off ebay in mint, still sealed condition
here is a scan

ampex2917io.jpg
 
You must log in or register to reply here.
Back
Top