Not sure if this is the correct forum for this question, but here goes anyhow....
I need to install a load of 3mm leds in pre-drilled holes in an acrylic panel. The leds are a sliding, loose fit in the holes, but there is definitely no room for a led bezel or clip. There's no option to drill out the mounting holes to make room for a bezel either. The leds protrude through the panel by just about 1mm.
The only practical choice I seem to have is to use an adhesive of some sort. This is where I need help! I know you can't use cyano (superglue) types as it has a detrimental affect on the plastic of the led, but does anyone have any suggestions as to an alternative glue? Would silicon adhesive work do you think? I'm reluctant to buy that unless I know it will work for sure, as it's pricey stuff around here.
Your problem is that you are going to see anything you put as glue. Yes silicon would work as would epoxy, but would it not look a mess?
How are the LEDs being fixed? Can you not fix the acrylic to the led's mounting board.
@ Grumpy_Mike
The leds are all individually inserted into the pre-drilled holes. The holes are just small enough that the led flange stops it being pushed right through. After insertion/retaining in place, each led is then individually wired as part of a matrix. The acrylic is coloured black so wouldn't show through if it was kept clear of the front surface. The glue would have to be either thin enough to put in the hole before the led (and then wipe off any excess - not an easy prospect if its a solvent type glue), or thick enough to "splodge" on the base of the led to stop it falling out of the panel - which leads me to.... @Riva
I have used hot glue up until now, and it is my fall-back method, but I was hoping that someone knew of a glue that might be compatible with acrylic and leds.
Though with hot glue you need to consider whether or not your LEDs will be used in places like the US southwest, Death Valley, etc. where the temps can be higher than the melting point of hot glue.
That's a valid point MM. I'm not 100% sure where these panels will end up - I'll just have to stipulate that they should only be located in an air-con room
Another cheap option is to use something like silicon sealant (like you put round the bath) but the cure times can make the job easier/harder depending if you need the items ASAP or a few hours later.
Hmmmm, I think I might experiment with some nail varnish tonight (ooooer, did that sound kind of, well, wrong?! :*). Provided the acetone doen't affect the acrylic or led plastic that might work. I'm sure my wife has some clear varnish I could, errr, borrow.
I did consider silicon sealant, but the drying time is, as pointed out, a bit long and it has a habit of transferring itself onto everything within 10 feet - I know, I've just fitted a new shower and have white silicon everywhere!
Thanks for the ideas guys, a few trial runs tonight I think
Hi CrossRoads
I think the Loctite is cyano based, so will probably degrade the led plastic but the Gorilla glue sounds interesting. Our Homebase chain stock it, so I'll give them a visit tomorrow and price it up.
Surely epoxy two-part adhesive will work nicely (bit more hassle than hot-melt glue, but
will stand high temperatures much better (hot-melt glue sticks melt in a car left out in the
sun even in the UK climate)
The panels are pre existing unfortunately, so I'm stuck with the thickness. Must admit, I hadn't considered a mechanical solution, so thanks for the idea LarryD.
Epoxy would certainly do the job MarkT, but as I have to install 48 leds in each panel, getting enough installed before the mix goes off could be problematic. I think though, that this is the route I'll go with, especially if I don't use the fast curing type.
