Silicone caulk usage

[beeiilll]

With the advance of the use of RGB lighting it needs to be noted that the sealing of the electrical connections and RGB strips (whether they are encased in a coating or inside a silicone sleeve), there remains a need to seal any open spots to prevent water ingress and potential damage to components or electrical shorts.
Some may think that it is better to leave the connection somewhat open to air so as to let things dry out. I will not make any attempt to debate that here but want to give folks some information on silicone caulks to help prevent troubles later on.

Most people who own homes have used silicone caulk at one time or another to patch up around windows or doors or seal around a tub or shower.
You may be familiar with the nasty vinegar smell that some caulks give off? These types of caulk are ones to stay away from when working with your lights. These are an acid type of cure that is bad for any electrical components and other things as well.
Here is a nice little page from a site in the UK that I found that will give you some better idea on the types of silicone caulks and their usage.
http://www.thewindowman.co.uk/sealants.htm

A typical form of the so called neutral caulk is GE Silicone II. It should be noted that the regular GE or GE I type of caulk is NOT a neutral cure and should not be used.
Of course GE does NOT recommend that silicone caulk of any kind be used on electrical but we tend to work around that for this hobby.

I have not done extensive research on this as of yet, but most silicone caulks even if neutral cure are not really rated for electrical component applications unless you get into the area of RTV type silicone.
This may give you some info on RTV types:
http://www.korsil.ru/content/files/catalog1/rtv_5240%20.pdf

Usually you end up getting into the area of industrial or military RTVs and/or two part potting compounds when looking for safe types of materials for electrical connections and components.
While they are the best, you also will pay a large price for them and that alone may deter most from their usage, especially in something such as a hobby.
I use two part potting compounds for things like permanent connections that I know I will never want to disturb or where there are connections to weatherproof connectors from components.
I think that the relatively cheap GE II, DAP, or some similar style of neutral cure silicone will be more than adequate for connections from RGB strips to wiring leads or strip to strip connections.
Another venue for the neutral cure style of silicone is automotive, marine, and aircraft suppliers (although the aircraft ones will be more than likely very expensive).
Another possible option would be to use a form of plastic epoxy for connections such as Locktite:
http://www.homedepot.com/buy/paint/adhesives-tape/0-85-fl-oz-plastic-epoxy-loctite-54207.html
which you can find from many home center style outlets. I have used this form of epoxy to repair blowmolds with very good results but have yet to try it with any RGB components or electrical connections.
Another problem is that the RGB strips coming from China can have a few different types of coatings on them as well. Some say silicone and some are a resin coating or they use the silicone tubing to encase the strip or have both the tubing and a coating on them.
Whichever type you use will dictate the form and/or type of sealant that you will want to use.
Hopefully someone who is testing out some of the RGB strips can do a testing of different silicones soon to see how they hold up to weather, time, and the elements as well as how they adhere and seal the actual strips as well.

[beeiilll]

I have had a couple of people ask me as a follow up on this about liquid electrical tape and hot glue.
I use the liquid electrical tape myself both at work and for my own uses around home. It works as intended to seal and insulate electrical connections quite nicely (since that is what is was designed for after all).
The only drawback to my original post for RGB things is that the liquid tape is black and most RGB strips are white or clear and I would rather use a clear sealant on the strips that I have since they have a clear silicone coating on them already. But yes the liquid electrical tape would work just fine as well if that is what you like to use. I was more trying to make an invisible repair to an RGB strip when having to make the electrical connections or making one a certain lenght. Guess I am a little more than normally anal at that aspect of things.

As far as the use of hot glue, I have not tried it to seal electrical connections. I would be hesitant in using it for any connections that might have any flex to them as it will tend to break loose quite easily and not seal well. I also have no knowledge of what if any electrical resistance or insulating qualities that hot glue might have. Seems like it might not be the best item for insulating or sealing electrical to me but perhaps others can shed some light on how well it works over time. Perhaps for a rigid connection that does not move at all it might afford adequate protection. I just have no working knowledge at this point to make any recommendations one way or another on it.
My own personal feeling is that it is really not intended for electrical work so I would not use it.

It may be prudent for someone who has conversations on a regular basis with Ray Wu to inquire as to what they are actually using for the coatings on the RGB strips that are being made? Perhaps it would be nice to find out if it is a type of silicone or resin that can be purchased over the counter so that we can make it available to the general public for this hobby if the price of it was not too bad?

[beeiilll]

Well since I started this, I want to add some actual testing to things to see what really does work and what doesn't for this.

So I took a reel of dumb rgb strip that I have and cut off 4 individual sections for testing.

I found that a good pair of sharp scissors will make a nice clean cut through the rgb strip. To remove the coating I used a razor knife and very carefully pushed it gently down through the coating till it was almost to the strip. Then it was easy to peel the coating back and off the connections very cleanly without any trouble at all.


I would also recommend that anyone who is going to work with the strip purchase a pair of hemostats as shown as they make it so nice and easy to hold the wires to solder to the strip. A set of helping hands is also a nice thing to have to make it easier to hold things while working on this stuff.

Then I took some 24 awg solid copper phone wire and soldered connections on the strips to simulate the wiring onto the strips. I used an old 40 watt soldering iron that I have with a chisel tip on it to get somewhat of a "rough finish" for the connections as not everybody will have a nice $200 soldering station to work with and I want this to be more of a real world style of test for everybody to use.

Then I used some various coatings that I have here to cover the connections and also sealed up the ends of the wires so that moisture won't get in from the end and make a difference.

So now I have these 4 pieces attached to a piece of wood strip and I will put it outside in the weather tomorrow after all the coatings have had 24 hours to cure.


I plan to leave this out and photo it everyday for at least the fist month or two to see how the weather affects the different coatings.

The only thing I did not have on hand right now was any clear neutral silicone but I do have a white so I used that for now.


Another thing I noticed was that the hot glue was very easy to apply and does give you a nice see thorugh covering. I may have to change my opinion of it even though it still is not a "recommended" coating for electrical by any manufacturer that I can find so far and there are very many different types of hot glue as well as the temperature ratings for it out there. But it was nice to work with over almost any of the other coatings.


So now let the testing begin and I will see how these hold up through the summer and next fall and winter.

I will try to make updates on this every month or so.

Bill

[beeiilll]

Well Thanks to Jeff for donating some silicone tubing covering to the cause, I now have 2 pieces of it out in the weather for testing.
Today is the 2 week mark for the RGB strips that I put out originally. I added the 2 pieces of silicone tubing last night inside so the silicone adhesive could set up and just put the test setup back outdoors this morning.
The silicone strips I made up one with a piece of dumb strip inside it with wires soldered on and the ends of the silicone tubing sealed. The other piece of tubing is empty with one end sealed to prevent the wind from blowing though the piece although I want some air to be able to circulate into it.
Nothing to report so far on the test other than some very light either oxidation or else it is the flux remanents discoloring on the one strip that I soldered 2 wires on but has no protection on the solder joints. The 2 adjacent copper pads are bright and shiny which makes me think that this is more the flux degrading than actual corrosion of the solder, but it really is too early to tell at this point.

The weather for the past 2 weeks has been pretty much overcast with rainy and snowy periods with the temps ranging from low 20's at night to mid 40's during the day. Of course these are F and not C so those folks who live in Aus or Can will have to forgive me and convert for themselves. Guess I better get a dual reading thermometer on the next shopping trip and post it on the photos for you!
So the waiting and watching will continue for months and we shall see what we shall see!
I have also begun contacting manufacturers of sealants and hot melt adhesive (HMA or hot glue if you like) to get the actual data sheets on the sealants as well as any recommendations on useage of these substances on electronic and electrical connections.
This way the testing will have actual "factory specs" to base the results on and not my own personal opinion or observations which only seems like the right way to do this.

Attached files

[beeiilll]

A close up of the new silicone tubing for testing for you.

Attached files

[beeiilll]

Well after a month out in the weather there is not too much to report on the test strips yet.
It does appear that they do get a cloudy haze to them on wet and rainy days though as you can see from today’s pictures.

I do see the beginnings of corrosion effects on the test strip that has the 100% silicone on it under a microscope. I believe that this is more of chemical effect corrosion than a moisture corrosion which is too be expected from the silicone. A joint using neutral silicone does not show this effect yet.

As far as materials to use for connections, I have been in touch with quite a few companies and am waiting for test samples as well as data sheets for various materials to be able to give good data to folks and for my sample analysis’ purposes.

I have spoken with 6 different companies about the use of hot melt for RGB connections with varying opinions and results. Four out of the six companies do not recommend the use of hot melt adhesive for outside use, electrical connection sealing/insulating, or both. The other 2 companies are sending me samples of hot melt with data sheets so I can run some tests on them myself but these are not the average household hot melt adhesives that you would purchase from normal sources of the stuff. These are specific hot melt adhesives that are used for encapsulating items or being used for mold injection uses although the companies have assured me that the glue would be useable by the average consumer without special equipment (ie., a standard hot melt gun will work with it). This should be interesting to see once I have some of it to play with.

I have been in touch with companies on using neutral silicone as well and have data sheets and some samples of it coming as well to test.

Overall not much else new but I am excited by the hot melt adhesive possibilities as this would make a very quick and easy sealing item for use by people in this hobby. I have always been a firm user of potting compounds or the neutral silicone myself but as we all know, times do change and this could be a nice new addition that would save a lot of time for assembly of items.

Attached files

[beeiilll]

Jeff Millard wrote:

I haven't spent much time looking into a product that is intended for use with electronics, but it's for sure I'll need something before much longer. Any help on this would be greatly appreciated. No guesswork and conjecture please, if you know for sure a product is recommended for this type of application... that's what we need specifically.

Jeff

I'm with you on that Jeff.
I want to be sure that what I use will work right and safely for this and that is why I got into this testing and researching to see what is available out there.
I do have a good silicone sealant that is rated for electronic work and a couple of other options so far that are viable for useage as well.
I am really looking forward to the samples of the Hot melt stuff to come in as that would certainly be a time saver and easy to use.
Hopefully my samples will show up soon and I can let others know about them as well.

[TGabriel]

Jeff
Check out Dow Corning 3145 RTV it meets MIL-A-46146 spec.
Thomas

[beeiilll]

Well first off, my appologies for not doing an update before now. I have been very busy with rehabbing as well as some health issues that are on-going and not so much fun as I get older.

The first item to fail the outdoor testing was the hot melt glue at 57 days into test. It started to peel away from the connection and has let moisture into the electrical connection as well as the cable sleeve.

I also have not found even one manufacturer who will give any endorsement or even some casual okay to using hot melt with RGB strips. The only hot melt type that any of them will talk about or endorse is a reactive hot melt which is two step process that must be done in a controlled environment so it is out of the question for this hobby.

The next one to show signs of failure is plastic dip coating so far. It is beginning to fray around the edges and looks to be starting to peel up off the RGB strip. So I guess I can't give this one much of an endorsement either at this point.

All the other sealants look to be performing satisfactory so far even though the RGB strip samples are starting to show some yellowing effects from the sun and outside environment.

This year so far has been very humid and hot here much more so than a normal year, but probably normal for other parts of the country.

So there you have it for now. I'll try to be a little more diligent about getting updates on this more frequently!

[SoCalJimH]

Hi beeiilll, I noted in your #2 post that the liquid tape you use is black and you were reluctant to use it due to the ribbons are white/clear. I was in Home Depot last week and ran across white liquid tape by the same company that makes the black version-- "GB" or "Gardner Bender" (GardnerBender.com) Item- LTW-400. In addition to the black and white they also make red and green.

Hope this helps!

[beeiilll]

Thanks for the info. I had learned about the other colors for the liquid tape and may try some of it out sometime. My biggest concern was to try and find clear or white types of sealants to use to make them more invisible but I really wanted clear so that I could see through the stuff and see how it was holding up as well as if it was affecting the strips over the course of the test.

Color really is not a big concern but to find ones that are the same as the strip is just nicer in my opinion as they tend to blend in with the strip and make the connections less visible.

But for testing the black stuff will work just as well.

[Guest wbottomley]

Bill... thanks for being a guinea pig for this project. Your information has been very helpful and will be put to good use.

[spomalley]

Very informative, thanks for the update.

[beeiilll]

Here are a couple of photos of the testing as of today 8-10-2012.

As you can see the hot glue is letting go pretty much. Also the strips are very cloudy looking now after only 4 months out in the weather, although the strip that is encased in the silicone sleeve is still fairly clear and has not degraded like the ones that are just the resin coating.

[magish01]

Beeiilll,

So do any of your test strips use silicone sealant and if so, which type (non-corrosive I hope)?

[SoCalJimH]

See post #1, 3rd paragraph.

[beeiilll]

Yes I am using a neutral type of GE silicone caulk and a 100% silicone type so that I can see the difference between them.

I am also using a latex silicone caulk for one as well.

You have to be careful with silicone caulk and really read on them to make sure you get a neutral one (as well as one that is safe for electrical connections if you are using it for that too).

A very good type of electronic grade silicone caulk for use can be found from Altex:

http://www.altex.com/GC-Waldom-Electronic-Grade-Silicone-SealantAdhesive-3oz-Tube-19-155-P141838C10576.aspx

My actual reason for this testing was to find a good neutral silicone caulk and compare it to other forms of sealants just for use in this hobby environment.

So far the hot melt and plastic dip coatings are failing quickly and are out for this (IMO).

[magish01]

Thanks for the link and your recommendation

[beeiilll]

Well I finished the testing on sealants for RGB.  I made it into a pdf file to make it easier to post and view.

But since the LOR forum tells me that I can't post anything bigger than 12. KB (what's up with that by the way?), I guess you will have to one of the other forums to see the results.

I posted it over on PC, the Australian forum, and Holiday University.

[SteveMaris]

Beeiilll,

Can you post a link to the PC thread? 

Thank you for doing this.