Here's a guide to pulling nails from recycled wood.
I've recycled about 15,000 tons of building materials and therefore consider myself an expert on removing nails from old wood. I've developed many techniques to expedite this process and I've also copied from others who do this.
Good gloves, goggles, earplugs and nail proof footwear are advisable. I've seen more puncture wounds from sloppy de-nailing sites than from any other process in demolition. More than one person wearing shorts and sandals has gotten their feet tangled up on a sloppy site and fallen flat out onto the naily boards they were working on. Darwinism in action
Whenever you're de-nailing wood it's a good idea to set up a comfortable work station. I like good solid sawhorses set at about crotch height. If I'm doing tongue and groove flooring or other material containing small nails I'll set the horses higher than this. The lower setting is great for heavy framing lumber containing big nails. After the nails are hammered back and the wood is flipped you'll want to use a 3 foot prybar to withdraw big spikes. If the horses are set too high you are likely to whack your self in the head with the bar. A quick snapping action with the bar uses less energy than a slow pulling type of withdrawal.
The hammer--- It is inadvisable to use a heavy framing hammer for most de-nailing purposes. You simply don't need all that power and you'll tire yourself out for nothing. The most useful hammer I've used is one that was designed for drywall installation. It is very light but with a really large diameter head. The broad head means that even quite inaccurate swings are likely to hit the nail. A fast strike with a light hammer is more effective than a slow strike with a heavy hammer. What you're trying to accomplish is to shock the rust and static friction to get the nail started. The heavier hammer traveling slowly will have much of its energy absorbed as the wood bounces. Always straighten bent nails with the claws of your hammer before hammering them.
Withdrawing spikes---- Once you've hammered big spikes to expose 1/4 inch of the head and shaft of all the spikes on one side of a plank it's time to flip it over and yank those big nails with a 3 foot prybar. I often see people hammer on the spikes until the point of the nail is flush with the plank. 10 strikes or more are not uncommon with amateurs. Most of this effort is wasted since a good bar will rip the nail from the wood in one solid yank if you just expose 1/4 inch of the nail head and shaft. Hammers are useless for this process but I frequently watch people work this way. They give many repeated jerks until they either tire their forearms or break the hammer handle. A person working with a hammer and bar will be much more productive, less likely to induce tendinitis or other injuries and will not break tools.
De-nailing plywood---- The Drop Method--- Whenever I need to remove large quantities of small nails from plywood I work with a helper and we carefully drop the sheets onto concrete or asphalt so that all of the points of the nails strike the concrete at once. Usually only one drop is necessary to get enough head exposed so that we can strip the nails. Hammers or small prybars are best for withdrawing these nails since they have little holding power after they have been shocked loose. Sometimes after the initial drop we work our way around the sheet tapping lightly with a sledgehammer in tamper fashion and many of the nails pop out on their own. For this process to work it's important that the nails be relatively straight before the drop. If the wood is recently removed from a structure most of the nails will be straight enough. Use the claws of your hammer to straighten the others. When ever you transport plywood and lumber with the nails in you're likely to bend many of them over and this will make de-nailing more difficult. Better to process the materials as they are produced. This also lets you get a bigger and safer load on your truck.
The drop method also works on 1 inch boards and sometimes planks but you'll need to be quite accurate so as not to bend the nails upon impact. Don't try this on a nice concrete patio or new driveway! You'll leave 1 million little holes which won't be appreciated later. It's better to find an area of concrete or asphalt that is going to be torn up at the demolition site.
De-nailing tongue and groove materials--- Generally tongue and groove materials are more bouncy and floppy than other wood you will encounter so it's very important to set up a proper workstation. The nails will generally be driven in on about a 45° angle so it sometimes helps to tilt the wood with one hand while striking the nail. This makes for less bounce. Once you hammer all the nail points it's time to pull the nails. For this you need a curved claw hammer and the pressure point for leverage should be the tounge and not the finished face of the flooring or wainscoting. Straight claw hammers are useless for this purpose since they invariably slip around and damage the finished surface. Using a grinder---- sometimes when nails are withdrawn they cause splitting or take out a chunk of the finished surface rendering the finished product worthless. An angle grinder with a very thin cutoff blade can be used to cut these nails off just below the bottom surface of your flooring. Use the lightest grinder you can find and protect your ears and eyes. Once you get on to grinding nails it will be much faster than other methods. Snapping nails----It is possible to snap many of the old square nails which are encountered in houses built before 1930. These nails often have just enough rust to make them cling to the wood and take out a chunk of finished surface if removed with a hammer. If you've got a strong forearm and thick leather gloves you can often snap these thin nails with the hand. I've also used pliers with a quick twisting motion to accomplish this.
De-nailing trim---- quite often trim in old houses has many layers of paint or varnish. When nails are hammered out they take out big chunks of wood and completely spoil the surface. Since trim nails have very small heads they can often be pulled out from the back side of the material using vise grips or a nail biting device sometimes called a side cutter. Basically you grab the nail tight against the wood and leverage the tool against the wood. Wear good gloves for this since there is a good chance that with a slip you will smack your hand into other nail points. I always start at one end of the board and work my way towards the other with all of my prying action going towards the area I have already stripped.
Tile nippers are a handy tool for nails. The rounded head offers leverage to slowly and gently peel out a nail. You must have a little bit of the nail exposed to get a grip. The sharp bite will grab hold. If you peel it out a ways and run out of fulcrum, grab the nail again close to the board, repeat.
Seed the Mind, Harvest Ideas.
My dad taught me to place a small 1X piece of wood under the center of the hammer, between the head and claw. With the claw on the nail , the wood between the ground and the hammer, the wood forms a fulcrum and the nails come out easily and straighter.
I learned that the big mistake when pulling nails with a claw/framing hammer is to rock the hammer from claw to head. Instead, take a bite, rock the hammer side to side, which will bend the nail as you go, taking a fresh bite each rock. Back and forth. This eliminates the possibility of breaking the handle, as well as reducing the effort. Same principle as using the nail puller hook on a roofing ax. Although, if I have a lot of nails to pull, I'll have a Wonderbar handy. I find your 3-ft crowbar unwieldy and tiring pretty quickly.
For trim boards, the same technique can be used from the back side, since trim heads will pull through. Also, dikes work well, and that's why I always keep a pair in my bags when I do trim work. 8d and above, I'll use the hammer; smaller, down to brads, the dikes are better. Use just enough pressure to grip, without cutting through.
The first pic is a headboard. most of the slats were made with oak salvaged from shipping pallets. The feet of the table came from the wood used on the bottom of a refrigerator to protect it during shipping.
Seed the Mind, Harvest Ideas.
4" putty knife laid flat under the head of whatever you use to pull a nail protects the surface. Flexible ones work fine, bend so the blade lies flat even if the handle is on the surface. For a better tool, cut the handle off a stiff putty knife so the blade will always lay flat - the stiffer knives have thicker metal and pretty much remove any chance of the fulcrum printing through, even on soft wood.
I find that using a puller (cats claw, jap puller, small wrecking bar, etc) that is as small as possible while still allowing the claw to fit around the nail works best for me. Instead of levering manually, I hit the end if the shaft with a hammer in the direction to pry out the nail. If I'm particularly spastic that day or if it's in an awkward position I use the flat side of the hammer head (sidewise) so I don't miss; or just hit it with a foot of 3/4" steel pipe. Smaller tools (if they work as well) don't tire you out or strain muscles as much.
Dull slightly and/or notch (slightly) the center of the end cutters so you can grab the nail hard w/out cutting it while you roll it out.
Biggest dremel tool, using the cut-off discs, makes the best nail cutter I've found. I think the mandrel will also fit the ZIP type tools rockers use to cut out electrical boxes - not sure about that one.
Similar to the nibblers, I like to use channel locks to peel out loosened nails. The issue I've had with nibblers is the hardened edge chipping from biting down too hard. Channel locks don't have this issue.
My nearly always foolproof method of removing trim
Score the painted, or kitted joint between, for instance the architrave and the door frame/ wall with a stanley knife,
Drive a paint scraper between the wall and the trim as close to a nail as you can get (If you can see them) , then drive a second paint scraper one under that.
Drive a wonder bar between the two paint scrapers and lever the architrave away about 10mm/ half inch.
Move to just under the next nail and repeat the process. When all of the trim has been levered away its then easy to remove it completely.
The two paint scrapers has the added effect of protecting the wall from the force of the wonderbar.
I say nearly always foolproof because it does't always work, and I can do foolish things.