I’ve gotten a few questions about how I made the bumpers for my packs, and thought I’d remembered the same topic coming up in the forums. I recently completed a set of bumpers and took pictures along the way. So here’s my attempt at a tutorial.
Before jumping into this, please be aware that, if you don’t know what you’re doing, attempting to make a bumper with this approach can be EXTREMELY dangerous. If you don’t know how to handle power tools safely, DO NOT ATTEMPT.
That said, here we go…
- First, you need to know how wide to make the inner portion of your bumper. You want it to fit snugly against your cyclotron. Measure across the widest portion of your cyclotron:
- Next, trace out the shape of your bumper. You only want to have to cut your bumper once, so its best to make a paper stencil first. This allows you to verify its width and shape before going any further. The piece of wood we’ll be using is 2"x8" so don’t make your stencil any taller than that.
The notch you’ll be cutting into the top of your bumper will be to hold the bumper plate (the flat portion of the bumper that will be added later). The best way to size it properly, is to hold the edge of the 2 x 3/4 piece of wood on edge to the stencil and trace around it (sorry, this will become more clear later).
- Once you’re happy with your stencil, transfer the shape to a piece of 2x8
- Cut the notch out of the top part of the bumper (where the flat piece will later go), as well as the outer curve of the bumper. Do not cut out the inner curve yet.
Notice in the above picture I cut out the inner curve of the bumper shown on the top left? Don’t do that -it was an accident.
- Here’ the scary part, route out the inner edges of the bumper. I use a 1" bit and have it set down about 1/4" from the outer edge of the bumper. Routing the bumper puts a lot of stress on the wood, which is why you don’t cut out the inner edge of the bumper beforehand.
Remember to go slow -I usually do multiple passes cutting a little deeper each time. Make sure to wear safety glasses and be prepared to get covered head-to-toe with saw dust. I have to flip over the bumper and route it from both sides in order to get the width of groove I’m looking for. I practice my technique of scrap wood until I feel I’ve got the depth and width I’m looking for.
Notice the scorch marks around the edge of the bumper? I suspect it means I was pushing too hard with the router and started to burn the wood…
A couple more pictures of the bumpers after they’ve been routed:
- The router doesn’t always leave the cleanest edge. Also, because I have to flip the bumper over to do the opposite side, The freshly cut lips could use a little TLC. I use a dremmel to clean up any imperfections.
Don’t they look pretty?
- Now you can cut the inner edge of the bumper. Again, go slow. Be careful when cutting around the “notch”, if you cut too close the wood it may crack. Then you get to start all over again, or attempt a fairly nasty repair.
and last one…
8 ) Time to sand! A palm sander works best. Use high-grit sandpaper and sand gently. Make sure you sand both sides, around the lips. and inside the grove.
- Time to add the bumper plate. You’re working with a piece of 2 x 3/4" wood. Insert it into the notch and determine where you want to make your cut.
- The bumper has anglular, curved edges. I go with small, 45 degree cuts on each corner, than sand them smooth.
- Think you’re done? Meh. Like everything else on a Proton Pack, its the finer details that need to be attended to before you can move on. Secure the bumper plate to the bumper from the other side. Drill small holes as guides for 3/4" screws. I like to counter sink the screw heads so that they’re not poking out.
Place your screws on the outer edges of the bumper plate. Leave the center clear so you’ll be able to attach your shock mount.
- Get out the sander again. Use it to level the bumper plate to the bumper (it will tend to rest a little high against the bumper arms.
- Unfortunately, the bumper plate never quite fits properly into the notch you’ve made. Use wood putty to fill in gaps.
After the putty has dried, sand it down with the palm sander. The end result should look like:
- Modge Podge. In the states, Modge Podge is mostly used to seal jig saw puzzles so they can be hung on walls. Its available in most craft stores as well as Walmart in the craft section. I use it to hide the wood grain of the bumper. Apply the stuff everywhere except along the underside. Apply sparingly and brush it on against the grain of the wood.
- Congratulations! You’ve done the hardwork. How about a couple of coats of primer?
- Last but not least, paint’em. I do two coats: the first coat is a flat black., the second is a misting with semi-gloss black.
Congratulations, you’re the proud parent of a brand new bumper, custom made to fit your pack.
I welcome suggestions on how to make this tutorial better. Please send me pics of the bumpers you make.
-KCGhostbuster
