My buddy and I decided to take these ammo can saddle bags to the next level by consuming copious amounts of whiskey and making them a little flashier, but still keep that "Holy crap, are those saddle bags ammo cans?" feel. They came out much cooler than I think either of us suspected they would.
2 Ammo Cans
Some scrap sheet metal (steel or aluminum, something with a decent compression strength)
Grinder wheels (cut off, grinding and stripping)
Liquid paint stripper
Nuts & Bolts
Acrylic or Rust proofing spray
These were inspired by another Instructable that can be found at https://www.instructables.com/id/Motorcycle-Saddlebags-from-Ammunition-Cases/
Step 1: Get the Ammo Can That Will Work Best for You
Army surplus stores sell them if you don't have a couple already. 40mm cans were chosen for this build. Note that 40mm ammo cans in particular have diagonal side rails to add extra rigidity to the box. This was a blessing and a curse for this build. The brackets we fabricated had to be made in such a way as to not infringe on the rail too much, and part of the rail on on one box had to be angle grinded away before it could be mounted flush with the motorcycle. That being said though, the amount of rigidity these rails give the box is significant and will make the box stronger and allow for far less vibration than a box without the side rail. We mounted these on my buddies 650cc Yamaha V-Star.
Step 2: Clean Up the Ammo Can
Once ammo cans are polished up and all the paint is removed, they look pretty cool. It's just steel, and personally I think the brushed steel look is a good one, and looks nice compared to that old military green. We toyed around with painting some black trim on the handles and lid just using spray paint after the can was all polished out and ended up removing it because the all steel look was a good one, and because the black spray paint, even with a few layers of clear acrylic on top, wasn't going to stand up to a lot of wear and especially so on the moving parts. I think if you really wanted to have these a different color you should probably consider getting them powder coated or chromed after you clean them up. Cleaning them up will make that cheaper, but powder coating and chroming are still not super cheap.
The next two stages of the cleanup are potentially hazardous to your health. Make sure to wear proper eye, hand and respiratory protection. The paint on these boxes is coming off in both fine dust and gooey liquid form, and the paint probably has all kinds of lead and other things in it from the lowest bidder, not to mention the vapors from the liquid paint stripper. All of this is easy to deal with, just make sure you do it.
For the cleanup of the cans we used a combination of a stripping wheel on an angle grinder and liquid paint stripper. The stripping wheel, which runs about 10 bucks and took two to complete this process, works really good on the flat surfaces. Hold the stripping wheel against the surface almost completely flat, with just a slight angle to work the paint off. Move the grinder around in a circular motion and avoid any sharp angles or protruding elements of the can, hitting this will disintegrate your stripping wheel much faster. Knock out all your flat surfaces first. Don't worry about getting a perfect pattern or shine just yet, just get the paint off, you'll come back to that after the liquid stripper part.
Now start applying the liquid stripper to the non-flat surfaces. Use a wire brush or steel wool to work it into the nooks and crannies. We also poured a little bit into a beverage can cut in half and used Q-Tips to apply it deep into the grooves. You can't let this stuff sit for long as it will just cake up and be equally as hard to get rid of as the original paint. Apply, scrub in, wait about 2 minutes tops and then wipe it off as best you can with a disposable rag and repeat. Once you've gotten the bulk of it off, apply a little bit to any remaining specks and hose the whole thing off to remove the chemicals... into a safe place.
By this point you should see very little to no paint left on the can but you will see a sort of staining effect from the chemical runoff and such. Now just take your angle grinder with the stripping wheel again and polish the whole thing up starting with the flat surfaces. On many of the non-flat surfaces you simply won't be able to buff with the grinder. You can get a similar stripping wheel but much smaller for a Dremel and do some of that detail work or just leave it as is, it looks pretty good without it.
Step 3: Create Your Mounting Brackets
I Googled around and found where other people had made mounting brackets for hard bags or simply bolted them directly to the bike with no intermediate piece. What I discovered was there isn't much in the way of one size fits all for this sort of thing. There are "Universal" mounting brackets but they are only universal because they have moving pieces so that the bracket can be adjusted to fit any bike, but that doesn't mean they fit any box. Normally it looks like people will buy a saddle bag/box specifically for the hole pattern in their box and then purchase a universal mounting bracket that adjusts to fit. These brackets run anywhere from 100 bucks a pair for what amounts to three bars of steel with joints/bolts for adjustment to several hundred dollars for some more sophisticated technology.
We opted to take about 10 dollars worth of scrap 1/4" billet aluminum I had laying around my shop/garage and fabricate a couple of plates to act as spacers and to account for the fact that the side of my buddies motorcycle is not completely flat so there was no way the ammo can could just bolt to the side of it without being a total mess.
First take the sheet of aluminum and hold it up next the fender of the bike and mark it for length, which should extend at least 1" from both bolts so that the pieces is at least 2" longer than the distance between to the two bolts for mounting bags.
The width of the pieces is not super critical, at least a few inches though... the wider the piece the more will be pressed against the box and the more support the box will receive, but some will have to be taken away to account for the rails on these 40mm cans anyway. I just split the difference on the piece of scrap I had laying around and marked it up for cutting.
Once your piece is marked as shown in the photo, use a metal cutting wheel on your grinder to create the two rectangular pieces.
Once the two pieces are cut, set one aside for awhile. Take the other and put it up against the bike again. Using a marker trace out areas where you need to remove some metal in order to get as flat of a fit against your bike as possible given it's natural curvature or any protruding surfaces while maintaining a 1" diameter of metal around what will become the two bolt holes. Grind away that excess metal using a bench grinder or grinding wheel on your angle grinder.
Now, to transfer a good bolt pattern onto your sheets of metal there are probably a dozen options. We simply used a piece of blue painters tape. First remove the bolts from the back of the motorcycle for holding bags and the fender. Put a strip of tape on the bike covering both holes, and with the edge of the tape about as level to the ground as you can get it by eyeballing it. Now push in on the tape where the bolt holes are, strong enough to make a permanent inward dimple on the tape but not so hard you push a tear into it or mangle the tape in any way. Once that is done remove the tape from the box being careful not to let it curl up or tear and transfer it to the last piece you finished grinding. Then take a center punch and place it directly in the middle of the dimple you created in the tape by pushing in on the bike, and give it one good solid tap with a hammer on a solid surface. This small dent will help to start your drill bit precisely where you want it and mark where you want to drill... in the picture I marked the dents with a sharpie so they were visible in the picture. Now, making sure to set your drill press to the appropriate speed for drilling this metal and thickness, drill out where you punched using a drill bit that matches the diameter of the bolts. Once this is done make sure you can get the bolts through the metal and that they thread straight into the bike with no problem.
Now you have one piece more or less complete. Take the other rectangle you set aside previously and clamp it tightly to the completed piece (using metal clamps, this work gets hot and will melt plastic clamps). Using a bench or angle grinder work these pieces clamped together until they are identical, then drill out the same holes in the second piece using the first as a template. To drill the holes in the second piece, the most critical part, perfectly just keep the two pieces clamped together and drill through the existing holes in the first piece into the second piece. You should now have two identical pieces.
In order to prevent scratching of the motorcycle frame once the can is mounted we used a little adhesive (you don't need much, it will be bolted anyway) to put a very thin strip of a foam rubber material similar to neoprene but more like foam on the plates on the inside where the piece will go against the bike. The material we used came from a box that held a helmet camera I bought, anything similar should work. You could also just use a couple of rubber washers... or gasket rubber... this stuff was just pretty good since it would help form a uniform surface against the very slightly curved surface of the bikes frame. If it deteriorates over time I expect I would use some gasket material to replace it.
Now just use the drill to knock out the holes in the rubber material for the bolts.
Step 4: Making the Holes in Your Ammo Cans
This part can be a little tricky and will be slightly different for each bike depending on how you want your cans to look. In our case we wanted the cans to end up in line with the exhaust pipes, so we set a bubble level on the exhaust pipes and used a quick square to determine the rise/angle of the pipes. Then on the first box we transferred that angle in reverse to the box and clamped one of the fabricated brackets to the box at that angle. Then we held the whole contraption up against the bike to make sure we didn't have too much whiskey and mess something up prior to drilling out the ammo can. Once everything is looking good, drill through your template and into the can to make the holes needed.
Once the first can is drilled out, don't drill the second can right away. Mount your first can and get it on tight, not super tight or permanent, but tight enough to check out the fit and make sure you like the angle and everything.
If you like the way the first can looks, it's time to drill out the second can. Rather than trying to replicate the angle transfer and everything you did on the first can, transfer from one can to the other to make absolutely sure there is no error in the height or angle of the second can. If things are off even 1/16" from front to back it will be visibly noticeable. In order to transfer the holes from the first can to the second can, take a thin but stiff piece of cardboard or cardstock that is cut so that each corner is exactly 90% (like a normal sheet of paper would be) and put it on the box that is already drilled covering the holes. Line up the edges of the cardstock so that they are lined up with the edges of the can and tape it down to the can. Now from inside the box mark through the drilled holes onto the cardstock with a Sharpie or other marker, filling in the hole completely so that it is transferred to the cardstock. Now remove the cardstock and line up the edges the way you had it on the other box, but on the reverse side of the box and tape it down. Now clamp the other bracket you fabricated down onto the cardstock and can making sandwhich meat out of the cardstock in such a way that you can see through the drilled holes in the bracket and that they are completely lined up with the black circles you drew from the inside of the other can.
Once that is all lined up set the two boxes next to each other the same way they would be on the bike. You should see that everything is lined up correctly and with the exception of drilling two more holes in the second can, ready to mount up. If it looks like it's going correctly, go ahead and drill the second can going straight through the bracket that is clamped on. Now your two cans, holes, brackets and all should be perfectly aligned to go on the bike. NOTE: If you used a 40mm ammo can like we did then you will have to angle grind some of the rail away on the second can in order to make this work. We took off about half of it, simply grinding out the small weld points and cutting through the rail about halfway through which is what we needed to make the bracket fit on the second can. Don't take off more rail than you have too, it adds rigidity to the box and rigidity is a good thing here.
Step 5: Finishing Touches
Once we were done with the last step we went ahead and mounted everything on and everything looked level and great. The bike was taken for a spin and it was discovered that there was some rattle coming from the cans carry handles. The black handle covers were taken off, which we realized was a better look anyway, and a quick little tack weld ensured they would never be rattling again (substitute welding with adhesive or whatever you can come up with to stop it). After that they were hung up and sprayed down with several coats of clear acrylic to prevent rust. Then they were mounted solidly using a bit of Locktite back to the bike and have been holding up good since.
For phase 2 we are considering numerous options such as LED lighting or even turning one of these into a subwoofer for a speaker system.