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Is it safe to use a hot-glue gun to keep LED's in place?

I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

Thanks,
--Farrell F.
 
B

Ban

Jan 1, 1970
0
I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big
white LED's will be tugging a little on their solder joints without
some sort of brace, and I would like to just use some hot-glue form a
glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

I have seen ugly hot-glue work on cheap boards to hold cables and big
components in place and even to insulate mains carrying traces on PCBs, so
there doesn't seem to be much conductivity. It is another question if the
epoxy surface of the LEDs will stick to it, but worth a try.
 
R

Rich Grise

Jan 1, 1970
0
I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

I'd build in some kind of strain relief for the LED leads, and smother
the assembly in RTV silicone rubber, that you can get at any hardware
store, "Home Club"-type store, or auto-parts store.

I wouldn't trust hot glue unless it's the type that dries resilient.
(Is there even any such of a thing?) Rigid stuff will crack, although
epoxy might have the kind of toughness that you need.

Good Luck!
Rich
 
M

Michael Black

Jan 1, 1970
0
I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

Thanks,
--Farrell F.

I'd say it's safe, if your question is about whether the glue
will hurt the components.

But my experience with hot glue is that it tends to be less permanent,
ie it gets too warm or too old and things fall apart. At least,
with plastics.

Epoxy, or as someone said RTV silicone whatever, tends to be
more permanent. The latter, which can be a real drag to remove
if you need to, has the advantage that there's a level of flexibility
to cushion those vibrations.

Michael
 
M

Michael Noone

Jan 1, 1970
0
[email protected] wrote in @z14g2000cwz.googlegroups.com:
I'm building some LED headlights for my radio-controlled car, and I
plan to use one of those project boards or whatever they're are called
to wire my LEDs and their resistors. But my RC car is gas powered, and
the engine puts out a lot of vibration. I'm concerned that my big white
LED's will be tugging a little on their solder joints without some sort
of brace, and I would like to just use some hot-glue form a glue gun.

But I'm new to electronics, and I do not know if the glue would be too
hot? and I doubt it, but does the glue conduct electricity?

Thanks,
--Farrell F.

When making connections to really small parts of circuit boards (ie
soldering a 30awg wire to a via on a motherboard) - I often will put a blob
of hot glue on it as a form of very basic strain relief. I've done various
tests with hot glue and at least whatever I'm using (from craft store) does
not conduct at all.

-Michael
 
Thanks all! I guess I will go with the RTV silicone stuff. My only
other question is if the silicone will effect the light output... my
LED's project their light in about a 60degree angle, and I wonder if
the silicone stuff will refocus the light?

What would be the best way to apply the stuff... just at the base of
the LEDs, or totally cover the LEDs in a think layer of the RTV silicon
stuff?

Lastly, since this will be on my RC car, dirt and other stuff will soon
cover parts of my stuff. I use the general parts-cleaners that
mechanics etc. use... spray can. Will that eat away at the RTV silicone
stuff, or cause harm to the resistors and LED's? Would just using soapy
warm water be better...and just let it dry thoroughly overnight?

Thanks again,
--Farrell F.
 
R

Rich Grise

Jan 1, 1970
0
Thanks all! I guess I will go with the RTV silicone stuff. My only other
question is if the silicone will effect the light output... my LED's
project their light in about a 60degree angle, and I wonder if the
silicone stuff will refocus the light?

Not if you don't slop it all over the top of the LED. :)
What would be the best way to apply the stuff... just at the base of the
LEDs, or totally cover the LEDs in a think layer of the RTV silicon stuff?

Put it between the LED and the board, with just enough excess to bring
its level up to the rim around the LED base, maybe a teeny tiny bit more:


top of LED
_
/ \
/ \
| |
| |
| |
--------------_| |_---- <- surface of goo
|___________| <- "rim" of LED
|leads|

etc. - be sure it gets forcefully squirted underneath the LED (unless
it's mounted flush, of course) so that you don't leave an air pocket.
Lastly, since this will be on my RC car, dirt and other stuff will soon
cover parts of my stuff. I use the general parts-cleaners that mechanics
etc. use... spray can. Will that eat away at the RTV silicone stuff, or
cause harm to the resistors and LED's? Would just using soapy warm water
be better...and just let it dry thoroughly overnight?

There's almost nothing that will attack RTV silicone. Acetone might
attack the plastic LED surface, although they should be epoxy, which
is also pretty impervious. Resistors are also inert, although there's
a possibility it could wash the paint stripes off, which won't harm
the actual resistor.

But be sure and use a cleaner spray that leaves no residue. Do NOT use
WD-40 for cleaning - that just gums stuff up. </voice of experience>

Hope This Helps!
Rich
 
M

Michael A. Terrell

Jan 1, 1970
0
Thanks all! I guess I will go with the RTV silicone stuff. My only
other question is if the silicone will effect the light output... my
LED's project their light in about a 60degree angle, and I wonder if
the silicone stuff will refocus the light?

What would be the best way to apply the stuff... just at the base of
the LEDs, or totally cover the LEDs in a think layer of the RTV silicon
stuff?

Lastly, since this will be on my RC car, dirt and other stuff will soon
cover parts of my stuff. I use the general parts-cleaners that
mechanics etc. use... spray can. Will that eat away at the RTV silicone
stuff, or cause harm to the resistors and LED's? Would just using soapy
warm water be better...and just let it dry thoroughly overnight?

Thanks again,
--Farrell F.


Be careful with RTV. There are two types and one corrodes wire. It
is marked, Not for electronic use.
 
M

Michael A. Terrell

Jan 1, 1970
0
Michael said:
I'd say it's safe, if your question is about whether the glue
will hurt the components.

But my experience with hot glue is that it tends to be less permanent,
ie it gets too warm or too old and things fall apart. At least,
with plastics.

Epoxy, or as someone said RTV silicone whatever, tends to be
more permanent. The latter, which can be a real drag to remove
if you need to, has the advantage that there's a level of flexibility
to cushion those vibrations.

Michael


I see a lot of LEDs mounted in consumer electronics with a little dab
of hot melt glue.
 
J

jibberjabber

Jan 1, 1970
0
There is hot-melt and there is hot-melt. We use a polyamide stick (Tec-bond
7718, black) and it's much better than the craft variety we used to use.
j
 
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