LED mounting without a bezel? Which glue?

[petey twofinger]

all these solutions are great , but sometimes there is no way around it and you need glue .

epoxy is great ,

hot glue can work for porous stuf , but when its an odd combo of materials and you need it to be strong :

this stuff , well i absolutely love it . i have used it to fix exhaust leaks ( with a soup can ) and that held for a year ....

http://www.jbweld.com/

dont use jb quik weld , its bad . clean / rough up the surface , always do that . use heat source , like a low watt bulb or something to aid in cure time , you do have a few minutes before it sets so often i utilize some masking tape or something to keep it from moving , or a clamp , but .

the only other thing i will say is that i didnt care or the 3mm metal led bezels from tayda . the 5's are great , and the lil black plastic ones look better in some cases but ...

[AnalogPackrat]

I use 10 minute hobby epoxy.  I bought a set (2 ~4oz bottles) 20 years ago when I was building RC planes and I still have 90% of it left.  Unlike CA (super glue) it does not spontaneously harden in the bottle.  I use it for LEDs and also to mount metal or plastic standoffs where I need them.

Here's the 5-minute version which is probably still plenty strong for stompbox uses...and cheap!

http://www.hobby-lobby.com/quik_cure_5_minute_epoxy_4.5_oz_1035180_prd1.htm

Yes, the typical silicone stuff usually contains acetic acid which will corrode metals and does evaporate.  Use GE Silicone II (available in most big box stores) if you want a flexible bond with no corrosive issues.  Silicone is more expensive and does not store well so I no longer bother with it.  It's great for bathrooms, but not stompboxes, IMO.

[Perrow]

awesome build Perrow

Thanks. I really like this way of mounting the led, will do it on more builds.

[joegagan]

i avoid epoxy for this function because i don't need the hassle of the mixing process, getting rid of the little piece of cardboard i mixed it on, cost of toothpicks, etc.

why use a machine gun when a pistol will do the job?

[greaser_au]

Just a few comments based on my years spent messing with these materials...

Cyanoacrylate - superglue- is an 'anaerobic' adhesive, it spontaneously hardens in the absence of air (that is why the new tube is only ever 1/4 full - never squeeze the air out!!!).  If the stuff isn't going off instantly the parts are joined, the gap is too big...     The surfaces being joined should not be 'keyed' (as in abraded to make more surface area).

Epoxy will stick best if the surfaces are lightly keyed & clean, and the glue applied with a mildly pointy tool to break the surface tension.

Normal RTV 'silastic' silicone rubber gives off acetic acid fumes as it cures. Look for 'neutral cure' - usually concrete sealant is neutral cure, but beware of odd colourants, who knows what they are. Clear or white is best. The best rule of thumb to tell is that acid cure is 24 hours cure time, and neutral cure is 72 hours.  The 'real thing'  is Dow Corning RTV738. Apply  under a little pressure for best adhesion, wipe a thin smear onto a surface with a toothpick before building it up (again to break the surface tension).

I'd use flat-top LEDs and a spacer made of some sheet material drilled & thicknessed so that the LED (when fully inserted to the base flange) is flush with the surface.

david