any ideas on bonding strips to plexi?

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(Brett Hansen) #1

any ideas on bonding strips to plexi? im thinking maybe aluminum channels but idk if that will look good. any other ideas? my test strips arnt water proof so ill take that into consideration.

(Michael Sharnet) #2

Permanent installation:
Rough cut plexi (leaving material for final finishing)
Sand and clean the plexi side that will attach the LEDs.
Create a map of where you want to place the strips and attach the map under the plexi so you can see where to put the leds later.
Cut and wire the LEDs - leave enough slack for wire flex.
Mask the edges of the plexi to form a 4mm ridge
Mix a batch of electronics safe clear epoxy (often called epoxy potting) that will cover the plexi surface (get 30 minute or so pot life)
Pour a 2mm thick coating of epoxy onto plexi in an even bubble free coat. You may need thinner and or heat gun to pop bubbles (check with epoxy manufacturer)
Most epoxies are self leveling. You might need to fill in some voids to help speed up the process.
If you haven’t already put on gloves now is the time. Your hands will stick to everything if you get epoxy on them.
Set leds into epoxy according to your map (be very careful not to introduce bubbles or dirt into the epoxy.
Follow the epoxy manufacturers directions and apply a second coat (to fully protect the LEDs.
Optional - I have seen instances where clear epoxy is used in the first layer and black epoxy is used in the second layer. The effect can be stunning.

For semi permanent installation:
Replace the epoxy with clear electronics safe silicone encapsulant or caulk that is (non-acid curing). and instead of coating the entire sheet, just fill the spaces where the leds will go.

If you have not used epoxy like this in the past - I recommend practicing before going for the final attempt.

Another way: edge light the plexi using aluminum channels attached to the sides. (If you go with the aluminum channel I would still encapsulate the LEDs for protection.

(Brett Hansen) #3

Wow thank you that will help a looot. This applys to side bonding correct? I like the idea of clear and black the car is black. Thank you very much

(Michael Sharnet) #4

If you decide to go with aluminum Sunny Chen is my go to on Aliexpress.com. Seems to have very fair prices on most aluminum and ships reasonably fast.

http://www.aliexpress.com/store/group/Led-aluminum-slot/816035_253646358.html

(Brett Hansen) #5

Thanks a lot :slight_smile: I swear your always looking out for me :slight_smile:

(Michael Sharnet) #6

And for epoxy, I go to these guys: http://stores.ebay.com/polymerproducts/

They have a couple of YouTube videos that show the process.

I have only used this method to coat a workbench with clear epoxy. If you go the epoxy route let me know how it worked for you.

Also - epoxy is very messy and if it sets on anything it becomes pretty much permanent unless you sand or hack it off. When I cover a workbench I put down two layers of cardboard with masking tape. And I have a specific spot where I enter and exit the work area (so I remember to remove my epoxy shoes - epoxy shoe prints are strange looking).

(Brett Hansen) #7

Cool thanks ill check it out I’ll post my progress I need to first see what I want to make

My goal is a multi part plexi hood with stripes along all sides I gotta test a lot first tho

(Michael Sharnet) #8

@Brett_Hansen My thinking was that the leds will shine through the plexi so these would be mounted with the LEDs facing the plexi.

(Brett Hansen) #9

my idea was to make a side lit panel that is frosted and made so the whole thing glows im just hoping i can do this i have my doubts for larger panels

(Jon Burroughs) #10

This is what you are looking for: http://lumilor.com/

(Brett Hansen) #11

thats interesting. very interesting thats something to look into although a little different then what im looking for but really cool thanks

(Brett Hansen) #12

i wish it was rgb haha

(Jon Burroughs) #13

They have blue, green and pink: BGP

(Brett Hansen) #14

lol yeah but i still like using plexi but that is awesome

(Bob Mulvey) #15

How about a light-duty adjustable wall shelving mount (the piece you attach to the wall) ? I found some at my local Ace Hardware and my weatherproof WS2812B strips fit inside the channel quite nicely. Cheap; $2.50 for a 6’ length.

(Brett Hansen) #16

That’s an option thanks :slight_smile:

(Mike Thornbury) #17

I would use a 3M industrial adhesive tape, like the Scotch-Weld variants. Much cleaner and easier than using epoxy. For LSE plastics you can treat them before bonding, for everything else, just clean the surface and stick the tape down. you can get permanent and semi-permanent tapes, depending on what you want to do.

I use LEDs in RC aircraft and in ‘arty’ installations and often want to retain the silicon tube they come in. If you’ve ever tried, bonding silicone tube is nearly impossible. I pre-treat the silicone with 3M AC78, then stick the velcro pads with permanent scotch-weld. It grips like a schoolboy.

For something as ‘active’ as plexiglass, just using a bonding tape will be enough for any permanent or semi-permanent installation.