How to waterproof buffer/line driver

[RobG]

I have been asked this question many times, so I have created a wiki page to show how I do it.

Waterproofing buffer/line driver wiki page
Buffer/line driver thread and wiki.

The 3 main products to use are:

* Silicone modified conformal coating - MG Chemicals Silicone Modified Conformal Coating, 55 ml Bottle with Brush Cap
I use this coating on any PCB that I will use outdoors, buffers, floods, etc. (55ml bottle is more than enough for all your projects.)

* Dielectric grease - Permatex 22058 Dielectric Tune-Up Grease, 3 oz. Tube
I put that s**t on everything Seriously, any connector or enclosure, this grease is the best thing to use.

* Dual wall adhesive lined 3/8" heat shrink tubing - Dual Wall Adhesive Lined 3:1 Heat Shrink Tubing 9.5mm (3/8") - Black
The best shrink tube to use. "Inner hot melt adhesive lining melts around the cabling or connectors and conforms to the shape of the connection to seal out the environmental elements as the tubing shrinks. The additional benefits of dual wall adhesive heat shrink tubing are that it also provides a stiffer covering compared to standard heat shrink which lends it self well to providing additional strain relief for connector to cable transitions and it can also be used to hold cables to a specific shapes. When using dual wall heat shrink tubing you want to consider the irregularities of the shape you are trying to seal. If you use a larger diameter tubing rather than a closely sized shrink tube you will get more adhesive to fill in the irregularities of the object to be sealed. The adhesive properties of of the adhesive lining are very similar to the characteristics of common hot melt glue and adheres to metals, plastics, rubbers and fabrics but keep in mind porous objects will have stronger adhesion. In some cases scuffing smooth objects will improve the adhesive properties of the adhesive lining of the heat shrink tubing."
Also, there are 2 versions available, 3:1 and 4:1 ratio, which is much better than standard 2:1.

[Santacarl]

Thanks Rob.....lots of good to know stuff on that wiki...... Last year I had several pigtails leak and as a result I had some strange things happen with pixels...... Never thought of using dielectric grease on the connectors... Don't know why it never occurred to me.....DOH.....

[RobG]

Yes, dielectric grease makes a world of difference. I had many problems with flood enclosures (even with the ones that were not converted to RGB, factory new,) and with Ray's connectors. Those problems went away when I started using grease. BTW, I will soon create wiki page about waterproofing floods.

Dual wall heat shrink tube is another gem. The hot melt adhesive not only seals, but it also makes really strong bond. With 0.5"-1" overlap, you will have hard time pulling your cable apart.

[jchuchla]

I use dielectric grease religiously myself.

The adhesive heat shrink however has been biting me a bit lately. I've had a number of splices this past season that had taken on some seepage that had been done with the dual wall adhesive shrink. These have been out for a few seasons already, so maybe it's a case of breakdown over time. But it has me somewhat cautious about where I'm going to use it in the future. Sometimes I have a very hard time removing this heatshrink, and others it comes off fairly easily. Maybe I just have a bad spool with inconsistent coverage. I don't know. But I thought I'd share the experience that it's not necessarily bulletproof.

[RobG]

That's why I always use 2nd line of defense either coating and/or grease inside.
That said, the problem could be with how the shrink was applied, not with the shrink itself. Cable jacket could have some grease or dirt on it, could be too smooth, or the melt was not hot enough or not heated all around during application. I always clean the jacket with alcohol and I make sure the melt is hot and liquid all around. If the jacket is too smooth, use fine sand paper to make it dull. So far, I had 0 failures, but I am using them for little over a year now.

[Santacarl]

That's why I always use 2nd line of defense either coating and/or grease inside.

Rob....I know this isn't the floods thread but, since you're talking conformance coatings, I was wondering if you use the conformance coating on the circuit boards on your floods?

[RobG]

Yes, I do, I coat all PCBs that are used outdoors.

[mrGrumpy]

Have you tried/used the areosol

https://www.amazon.com/MG-Chemicals-...60828769&psc=1

[RobG]

No, I think brush will let you do a better job. Plus, I usually "paint" assembled boards in the enclosure, with LED and wires, so using aerosol could get messy.

[DrewDennis]

Has anyone ever tried plastidip? LINK