The best way to stop my tapes from getting dents/dropouts? Also a question about contact cleaners

Hi all, been gone for a little while but I'm back with a question.

While ripping one of my cassettes I noticed in the playback that a few songs have drops and a sort of 'muddy' distortion in some places. I thought this might be an issue in my Technics' mechanism (I will need to give it a new belt at some point but it's clean), but when playing it on my Walkmans I noticed that these 'drops' are present when played with all 10+ of the models I have on hand.

When inspecting the tape I noticed some small dents on it, which I'm sure are responsible. I'm guessing these have been caused by an uneven pinch roller rubbing against it or perhaps the cause was due to knocking about during shipping (it was imported from Japan) or other handling-related issues. My question is if I can do anything to prevent this? All that comes to mind immediately is making sure the pinch rollers are even. I've never really figured out how to source new pinch rollers for all my varying Walkmans, but I've heard some rubber replenish sprays/liquids are good. How do you folks apply such a replenisher and is it effective? Otherwise I'm aware that I can't really do much to restore the quality on the tape at all (I can of course do some editing on Audacity but the quality will simply not match that of my CD or Vinyl rips, I just like the convenience of having the tape too).
I could of course transfer a high quality vinyl or CD rip to a blank C60 tape and then transplant the tape into the shell of the cassette in question... God bless Japan for selling so many cassette tapes with philips head screws Despite how effective or not this method is it's still a bit cumbersome and feels a little 'unauthentic' to me, I'd rather focus on preventing more degradation than outright replacing it for now.

As for may second question, I noticed that a few of my Walkmans exhibit a problem whereby the audio will sound a bit muddy when the headphone jack is plugged in fully, but it will sound better if I pull it out slightly. I have cleaned these headphone connections with IPA several times and it often works to solve the issue temporarily, but it seldom works as a long-term solution. When I first worked on these Walkmans I reflowed the solder for the headphone ports so an electrical mishap doesn't seem to be the root cause.

I've heard of people here using contact cleaner for these ports, are they any good? Is it just a spray application or is there more to it? I see a lot of these cleaners showing up on eBay or Amazon and I'm spoiled for choice!

This is a little disjointed but any help would be greatly appreciated. Thanks a lot!

 

Interesting finding! Is it possible to post photos of those dents? Now that I am buying used tapes off eBay, the only time I am getting dropouts is when a tape got "chewed up" by a previous owner, a small dent should result in just a split-second dropout.
A tip from one of a few professionals still living: use Naphta to rejuvenate pinchrollers. When restoring one of my Naks Willy Hermann advised me Not to use modern substitutes but use Naphta for the original/real pinchrollers... his advice got stuck because at that time I had just paid yet another $100 for a new Nak pinchrollers "made in Germany"...

IPA is a great stuff, but if you want to eliminate this "variable" then use DeoxIt. It is Magical! Professionals say that after using it you should spray/wash contacts with IPO, and I had finally bought IPA spray last week. But even without post-wash w/IPA all my bboxes fixed with DeoxIt many moons/years ago worked fine

 

I have just thought of a possible explanation for the drop outs. My Sony CFS45L had /has a magnet for the erase head (Shame on you Sony). It also had Cue and Review. If you used those the tape could fly up and hit the erase head causing a drop out. Once I realised what was happening I stopped using that feature.

 

Hi Longman, it's possible that the previous owner has done something like this to cause dropouts. I personally haven't tried recording over it and the Walkmans don't have erase heads, only my Technics does, so I'm not sure...

I'll have to post photos of it. Thanks for the advice of using Naptha Jorge! I will also get some deoxit. I should add that these drops are split second, in line with what you described. I just need to make sure not to make things worse!

 

I have a quick update on this situation. I bought a light magnifier earlier today and inspected the pinch rollers of my Walkmans. Thankfully nothing to dented but there is certainly stuff stuck to some of them. I suspect my old 79% IPA wasn't cutting it so I used some 90% to remove the gunk from the pinch rollers. Having played the same tape with the dropouts there are certainly less of the intermittent ones than before, but like I said there are some dents in the tape (small ones at that) which have sadly left some dropouts. It's a shame but as the W+F on my devices is fairly good (to spec or sometimes even above spec, my budget FX353 sounds almost as good as my DD ) and these are split seconds things - noticeable but now I will focus my efforts on ensuring this does not happen again. The tape is fairly old (going on 40 years) and it was previously owned by (I suspect) some Japanese guy who bought it way back when, it's likely through general use wear and tear has accumulated on the old boy.

Thank you for all your help. I have placed some orders for naptha and deoxit, should be arriving at some point soon. Would like to eliminate this headphone issue too! There's only so many times I'm willing to reflow these solder joints

 

A bit of cotton on a toothpick soaked with DeoxIt should solve your problem with headphone jack. As @Mister X suggested, start with IPA.
Avoid spraying DeoxIt all over Walkman, you do Not want it to get onto belts or plastic parts... it is not too corrosive but still try not to overdo it!

 

These last few years I follow this advice with both NOS and used cassettes, but have no idea if it makes any difference.
Another reason for uneven Play may be slightly deformed pinchroller: if it is not perfectly parallel to capstan and lost its "barrel-shape" to self-center tape path then tape may be pulled in a wavy pattern.