Backlit LED Sign
Check out how we build this LED backlit sign with home-made angle iron, LEDs, acrylic, plywood, and a plasma cut logo!
Also, if you want some great welding practice and/or a rocket stove, Richard sells some awesome rocket stove kits on his website 42fab.com If you use the code "YouCanMakeThisToo" you'll get $5 off!
This post contains affiliate links, for more information see my disclosures page.
First up I want to disclaim that we weren’t diligent with wearing full PPE. Just in the time it took to do this quick project I ended up with a pretty good sunburn on my left forearm. As always, whenever you’re working with tools, especially new ones, check the owners manual for the safety equipment and steps you should take.
What we’ve been doing is making some angle iron. I didn’t plan ahead to get the size angle we needed for this project, so I just picked up some flat bar from the home center and we made what we needed.
A big thing I learned during this project is that metal moves. When working with wood, I take into account how and if it’ll move through the seasons in the construction. For metal, I have to take into account how the heat from welding will affect the metal. Welding happens at very high temperature but then cools quite quickly. As metal cools, it contracts, with 10s of thousands of PSI force, so that has to be taken into account when fitting, setting up, and welding the pieces together.
After I ground my ugly welds smooth, there were still some fish hooks left, so I came back with some spot welds to fill them in and then grind them back again. After doing this a few times we ended with with some pretty smooth, albeit warped, pieces of angle.
The constraining dimension on this project was the width of acrylic I could get, so I cut it down to size and we used the acrylic and sight to miter the angle into the frame of the sign.
We did this in a few steps, first cutting the long sides, and then mocking things up to mark the length of the short sides. Richard did the cutting by eye with his angle grinder, so we finessed the pieces as needed and cleaned up the cuts with a flap disc.
One of the nice things about a metal project like this is you can always fill gaps with weld and then grind it back if needed, which is how we made the miters fit. Since the angle has a bit of bow to it, trying to find the perfect angle would’ve been a lot more challenging than just filling gaps.
When I welded the frame together, I welded in opposite corners to minimize building up too much heat at once. I welded the inside corners first, then the face of the frame, then gave things some time to cool before welding the outside corners.
Then it was time for a lot of grinding. The face was ground flat, and each corner ground to a tight radius.I wanted this to have a wood back, so I cut some scrap plywood to size and put some oil based poly on it to give it a nice tone. Once that dried I transferred the bow of the frame to it and cut the plywood to fit on the bandsaw. I’ll use this piece to also hold the battery pack for the LEDs, so I route out pocket for that to sit in.
Now it’s time to start adding the acrylic. I want this piece to have a lot of depth so I start by making some stand off’s for the main piece. I cut the curve they need and then epoxy them to frame before epoxying the main piece to the stand offs.
After the epoxy cures I add the LEDs to the frame. I wish that I added something to diffuse the light at this point, but I didn’t think about it. I may go back and do that later. Then we tap the back into place and secure the battery pack into place.
We were in a bit of a time crunch on this project and when we flipped it over we realized that the paint hadn’t had enough time to fully cure. So.. we carefully taped of the epoxy and added some more paint, then peeled off the tape and were super careful to not touch the paint as we wrapped up.
The last step of this sign is adding my logo! Chad from ManCrafting was awesome and powder coated the pieces for me while Richard was visiting him during Richard’s America Tour. These needed to have a bit of standoff from the acrylic, so we epoxied some #6 nuts onto the back of all pieces before laying them out. Once we had the layout where we wanted it, we started epoxying the pieces onto the acrylic.
Okay, so the last last thing to do is have a way to mount it, so I added a French cleat to the back to make it easy to hang on the wall.