soldering led pixel ribbons

[alchrisr01]

I am making some repairs to my pixel tree ribbons, replacing a few bad pixels, and am having a hard time cleaning the silicone filler off of the contacts so that I have a clean surface.  This is not the first time I have repaired them, but I don't remember having this much trouble getting a good tin. I am using an adjustable temp pencil iron and have it set on around 300' (?) and the solder seems to flow well, it just will not stick to the contacts.  I have tried to clean them with WD40 brand electrical contact cleaner and that seems to help some what.  I have watched David's video on holidaycoro and he makes it look so simple, but the ribbons he is using have no filler.  Anybody got any suggestions?

 

Thanks,

Chris

[TheDucks]

Same kind of problem. I am trying to remove the weather proofing (around the solder pads) on strips cut from  5M rolls (for window trimming)

In the 'Good old days', we used Acetone, MEK, Tricloro  to clean various electronic parts.  (I don't even think you can buy these in California without a special permit)

Now, even a gallon of Turpentine costs way more than a GALLON  OF GAS.

How does on even cut back the clear rubber without damaging the flex circuit, let alone, clean the residue to make good contact?

[k6ccc]

39 minutes ago, TheDucks said:

How does on even cut back the clear rubber without damaging the flex circuit, let alone, clean the residue to make good contact?

I take it you are dealing with the type of strip that is completely solid - as opposed to the strip inside a silicon tube.  I have never used the solid strip, but I can well imagine that it's a pain.  I'm almost thinking that your solution is going to be more mechanical rather than chemical.  The closest I have come to the solid tube strip is ends of strips where I have shot Silicon into the tube to waterproof it.  It's a ROYAL PAIN to get that off completely, but generally I have used a sharp knife to essentially scrape the silicon off.  Just have to be very careful and patient.

 

[TheDucks]

21 minutes ago, k6ccc said:

I take it you are dealing with the type of strip that is completely solid - as opposed to the strip inside a silicon tube.  I have never used the solid strip, but I can well imagine that it's a pain.  I'm almost thinking that your solution is going to be more mechanical rather than chemical.  The closest I have come to the solid tube strip is ends of strips where I have shot Silicon into the tube to waterproof it.  It's a ROYAL PAIN to get that off completely, but generally I have used a sharp knife to essentially scrape the silicon off.  Just have to be very careful and patient.

 

Yep, it comes on 8" reels. I have both RGB and White (monochrome). Patience is not my strong point

[alchrisr01]

Yep that is the stuff.  Mine came from Ray Wu several years ago.  I have a few spares I got from Holiday Coro but I don't want to swap a complete ribbon for one or two pixels out.  Lowes has all the chemicals you need here.  Always worries me a bit knowing all that flammable stuff is on a big shelf together!   Some of them we used to mix with race fuel!

 

I get the patience point, me neither......

 

[Mr. P]

I have used that solid strip for old dumb RGB props years ago. When I had to cut it I would cut the strip where needed then to clean off the soldering points I would use a razor cutting straight down then push out. It would always cleanly come off to expose the soldering points. Never used any cleaner and never had any issues with solder sticking.

[Little_b]

13 hours ago, Mr. P said:

I have used that solid strip for old dumb RGB props years ago. When I had to cut it I would cut the strip where needed then to clean off the soldering points I would use a razor cutting straight down then push out. It would always cleanly come off to expose the soldering points. Never used any cleaner and never had any issues with solder sticking.

+1

I would then put some silicon II over the joint to seal it back up.

[alchrisr01]

Sounds like we use the same method, Mr. P.  I also re-seal with silicone to waterproof the joint. I suppose I was hoping that somebody had some magic method out there.

I finally got everything working,.... until I raised the tree up and found some more ribbon issues!  I gave up and replaced one ribbon but was lucky enough to find a broken factory solder joint.  I cut into it and was able to melt them back together.  All is well for now.  I just hope everything survives the potential bad weather tonight.