An old wheelbarrow had been set out for the trash . . . the paint had mostly flaked off, and the tire was completely flat, but it was structurally sound, so I dragged it home for a second chance at life.
I fixed this one at TechShop.
Step 1: Disassemble the Wheelbarrow
The dis-assembly was actually the most difficult aspect of the whole project.
The wheelbarrow was held together by carriage bolts, meaning they have a nut on the threaded end, but instead of having a hexagonal head, the bolts have a low profile dome so they wont snag on whatever you might load into the wheelbarrow. They rely on a small square portion of the shaft just under the bolt head to prevent the bolt from spinning while tightening or loosening the nut.
The nuts had rusted onto the bolts pretty tightly, so the first order of business was to apply some PB-Blaster to each nut to help loosen things up. After letting them sit overnight most of the bolts came off pretty easily. A deep socket wrench was needed to get to two of the nuts that were set down in a metal trough that was too narrow for a crescent wrench.
A few stubborn nuts were so stuck that they twisted the bolt such that the square part of the bolt stripped out the wood or metal in which it was embedded. That left nothing to keep the bolt from spinning freely when putting torque on the nut. I was able to grip the very edge of all but one of the stuck bolts with a pair of vise grips and held the bolt in place while removing the nut.
The last nut/bolt pair was too well fused for a non-destructive extraction, so I cut through the bolt with an angle grinder. If you have to fall back to this method, cut the nut, not the head of the bolt. That square part of the bolt lies below the material's surface so it will prevent the removal of the bolt even if you grind away the entire head.
If you plan to re-use any of the old rusty bolts when reassembling the wheelbarrow, start soaking them in a rust remover now.
Step 2: Notes About Wheel Disassembly
The wheel is usually assembled as a multi-part assembly. The version i was working with was a tubeless wheel comprised of an axle, two bearings, a hub, a tire, and a valve stem.
Remove the tire from the wheel hub. This can take some work. There are plastic levers one can buy to help with this process, but since we're repainting everything anyway a couple of screwdrivers will do just fine. If there is still air in the tire, press on the center of the valve stem to release the pressure. Once the air has been released, pushing on the wall of the tire should separate it from the hub. This is called breaking the bead. Once the bead has been broken, insert a screwdriver between the tire and the hub then pull the handle of the screwdriver to the middle of the hub. This will pull a small pocket of the tire over the lip of the hub. Repeat this with a second screwdriver a few inches to the side of the first. More of the tire will be pulled out of he hub. Repeat as needed, possibly utilizing a third driver if moving one of the first two causes the lip to slip back into the hub.
Once you have freed one side of the tire, repeat the process with the second side of the tire, but pull the second side of the tire off of the same side of the hub! Otherwise you end up with a tire completely enveloping the hub, which is no fun at all.
Usually the axle will slide right out of the bearings once the wheel is unbolted from the frame of the wheelbarrow. Once the axle is removed, a long screwdriver or similar tool can be poked into the inside of the hub, positioned against the bearing on the opposite side of the hub, and tapped with a hammer to remove the bearings. Removing the bearings would be needed if the old ones had seized and no longer spun freely. Replacement bearings can be ordered online. I was unable to find any at local stores. Removing the bearings also makes the cleaning and painting of the hub easier even if you intend to keep using the old bearings.
In this case there was so much rust that not even a sledgehammer could budge that axel without damaging the hub. The bearings had also fused and no longer turned (the axle would turn in the bracket attaching it to the frame, producing an ungodly grinding squeal). They often sell replacement wheels at your local home improvement store, but they didn't have any axels at mine, so I couldn't use them without making a new axle. I just left the axel, bearings, and hub all fused together. Dousing the bearing in PB Blaster, clamping the axle securely in a vise and twisting the wheel back and forth with my hands i was eventually able to free up the bearings. They are still a little rough but the wheel will spin three rotations or so if given a spin by hand. It feels like a flake of rust is caught in one bearing, so I bet it'll loosen up more with use.
In order to properly clean and repaint the hub the valve stem needed to be removed. No amount of coaxing could get it out of the hub, so cutting it off was the only option. I picked up a replacement at the local auto parts store.
Step 3: Clean Up the Metal
Using an wire brush wheel on an angle grinder, go over each metal part to remove any loose rust and paint. Always use eye, ear, and respiratory protection.
I left the interior of the bucket alone, since it was coated in cement and i was going to mix cement in it too. It would have been a lot of grinding with a lot of extra dust, and very little payoff.
Once you've gotten all the loose junk off of the metal, use a sand blaster to remove the deep oxidization that will be visible as hard black deposits on the surface of the metal even after using the grinder. These areas will look like a patch of very small pits once it is properly cleaned. If you leave any oxidized areas, they will continue to rust away the metal even after repainting.
If your bushings are still attached to your wheel, be sure to cover them with tape to keep the sand and grinding dust out.
Step 4: Repaint
Once you have cleaned away all of the corrosion, you need to protect the newly exposed metal from suffering a similar fate.
There are several means to protect metal, but i opted for powder coating for its easy application and durability. If you do not have access to powder coating equipment, you can find brush on and spray can alternatives at your local hardware store.
If you need to wash your metal surfaces before applying your protective coating, be sure to dry the piece immediately or the metal will rust immediately. I found that a compressed air gun yielded a quick, lint-free dry, even on very rough, pitted surfaces.
Be sure to mask off the wheel bearing joint if you were unable to remove the bearings from the wheel. This will keep paint out of the bearings which could cause the wheel to seize up.
Step 5: Reassemble
Now to put everything back the way it was before. You did take note of how it went together, right?
Push the valve stem into the hole in the wheel hub. Clean the tire, especially where it will mate with the hub. Wrestle the tire back onto the hub. This should be much easier than taking it off and shouldn't require special tools. If you do need to use some extra leverage to get it back on, be sure to use plastic tools to avoid marring your new paint job.
If you removed the bearings push them back into the hub then reinstall the ax
Attaching the front bracket first helps reign in the wooden rails while assembling the rest of the 'barrow.
Slide the feet under the rails and rest the bucket on top, then run bolts through the four holes in the bottom of the bucket, through the wooden rails, and out through the metal foot rails.
Attach the front braces to the bucket, then flip the whole thing over for the last step of bolting on the wheel, which will also secure the bottom of the front braces that attach to the bucket.