Wednesday, January 30, 2013

Dressing Metal Tools

Metal on metal is a dangerous combination. Generally, hammers and other striking tools are made of hard steel and the tools they strike are slightly softer steel. This is to prevent chipping; metal shards chipping off of the hammer or tool. But the end result is that the tool eventually starts to look like a mushroom from the softer metal flowing under repeated blows (much like blacksmithing without the heat).

This mushrooming then becomes very dangerous because the metal curls away from the surface being hammered and big pieces can shear off and become shrapnel. Without appropriate eye and face protection one could be blinded.

So what do you do? Throw out the tool as unservicable? Buy a new one to be safe? The answer is no and no. You redress the striking surface. Here is how.

This picture shows a splitting wedge but these tips can be applied to any similar tool such as a chisel or rock drill. As you can see the top (left in this photo) has begun to curl over. This tool is long over due for a proper dressing.

 This close up shows where two pieces of the metal curling have already chipped off. I had loaned this tool out to a relative and he is inexperienced and struck off center when he was splitting some logs. Luckily no one was hurt by this shrapnel. But when the tool was returned I decided to fix the problem right away.

I have an old bench grinder but you could also use a hand-held angle grinder or even a course file.

Metal File, Bench Grinder, and Angle Grinder

The object of dressing a tool is to remove the unsafe metal and return the striking surface to a smooth, safe configuration.  If you use a grinder you have to be careful to not over heat the metal. Go slow and only grind for a few seconds on each angle. Remove small amounts of metal at a time.

Once you have ground off the curling metal your tool should look something like this. It won't be exactly as original because the tool has been reshaped by the hammering and removal of metal. But you can return the basic profile of the striking surface close to the original. As long as you grind or file off all the excess metal you will regain a usable tool.

Once I grind off the curled metal I like to round off the head so that it doesn't get damaged as quickly in the future. This takes a little practice but you just need to slowly roll the surface of the tool across your grinder.

Good metal tools are not cheap so being able to redress your own tools will save you a lot of money. I have cabinets full of tools that others had thrown out because they could no longer be safely used. I picked them up for free, took them home, and spent a few minutes on each tool to redress them. I have far more cold chisels than I could ever use but I'd rather have more than less. If needed I could sell some of them for a few bucks.

Tuesday, January 22, 2013

Replacing a Broken Sledgehammer Handle

I'm going to expand the scope of my subjects. This is the first.

I grew up working on the family farm and our family campground.  As the only boy in the family of seven, most of the repair and maintenance tasks fell on me. In some cases my dad had shown me how to do these jobs, in some cases I learned by watching someone else do a similar task, and in many cases I was left to figure it out on my own. I have to say my father took it for granted that I knew how to do certain things even though I had never done it before nor seen it done. But I was a clever boy and an even more inventive teenager. I can do basic carpentry, plumbing, electrical, and mechanical constructions and repairs. With the advent of the Internet I have greatly expanded my capabilities. As a result, I have fallen into the same attitude my father had; I presume that most men can do these same types of tasks. 

It fact, most men can no longer do many of these things or they hire others to do them for convenience.  If you have the money you have the luxery of trading cash for convenience and your time. But most of us do not have an excess amount of cash laying around.

Starting with this Post I am going to walk you through maintenance and repair jobs I do, which will save you considerable money if you do them yourself. But if you live near me in Northeast Pennsylvania, you can hire me to do them for you!

Replacing a Broken Handle:

This will be specifically about replacing a broken handle on a sledgehammer but any wood handle can be replaced the same way.

New handle, broken handle, cause of broken handle
How do most handles get broken?  Mostly by hitting the intended target with the handle instead of the metal head of the tool.  In this case a family member was splitting wood with my wedge and sledgehammer and it was broken. Some tool stores will fix it for you but you will then buy the handle, at a premium, and then pay for the labor as well.

How is a wooden handle held into the tool head? By a simple wood or metal wedge.

The channel through the tool head is slightly different on the two ends. One side, the bottom opening, is a straight-sided channel or hole. The other side, the top in this case, is beveled. The bevel is so that the handle can be wedged outward to lock the handle in place. This is done by hammering a wood or metal wedge into the top of the handle and it expands out to fill the beveled space. In my case, the wedge used in the old handle was metal. To remove the old handle you have to remove the wedge.

These two pictures show you what a metal wedge looks like. It is ridged so that it cannot back out of the handle as the tool is used. Wooden wedges are usually smooth and stay in place through wood on wood friction.

Because the metal wedge is ridged, it has to be freed from the surrounding wood. The best way I have found to do this is to drill several holes on both side of the wedge.

The metal wedges are generally soft metal but you still need to be very careful and precise when drilling these holes. The drill bit can get stuck and suddenly twist the drill in your hand or spin the tool head if you are using a drill press. I use a hand drill but a drill press might be more precise if you are not very experienced. Remove as much wood as you can drilling deep enough that you go below the bottom of the wedge.

Once I have drilled straight down I usually make a couple of passes at an angle to remove some of the wood between the holes.

This is a little hard to see but once you remove as much wood as you can you need to pull out the wedge. I used an old screwdriver to loosen up the wedge and then grabbed it with pump pliers and wiggled it free.

With the wedge pulled out you can now push out the old handle. It will only go one way, down toward the handle side of the tool head. I usually use a blunt punch and a hammer to pound it out of the tool head. Sometimes it is rusted fast or swelled due to absorbtion of moisture and/or oil. But a couple good whacks with a hammer should punch it out.  If not, get out your drill, place a larger bit in it, and completely drill through the full length of the wood.

Once the old handle is out it is time to insert the new handle. Make sure you insert the handle from the un-beveled side of the tool head. The beveled side should be facing up. Place the handle in the bottom of the tool head and then slam the handle straight down onto a hard surface. The weight of the tool head will cause it to drive down the handle as far as it can go. Once you hear a solid sound when you hit the handle on the ground or work bench top, it is as far on the handle as it is likely to go. If you keep driving the handle into the head it will start to splinter.

As you can see, the handle sticks out the top of the tool head. This excess is because these handles fit more than one type of tool and some are wider. This excess must be removed before wedging the new handle. I use a metal cutting hack saw because a wood cutting saw will be damaged doing this.

The handle has a slot cut into it. When you drive the handle into the tool head this crushes together to fit snuggly in the tool head. That slot is where the wedge will be driven. I am going to use the wooden wedge, I usually prefer wood wedges with new handles.

Place the wedge into the slot cut into the handle and carefully hammer it into the handle. Wooden wedges will easily split if you don't hit it square so be careful. Once it is solidly in as far as it will go stop hammering it or you will split the wedge. Cut off the excess so it is flush and then hammer it a few more times to slightly depress it into the handle. When it is cut flush it can't really split so this is safe to do.

You are now done. This is at most a 20-30 minute job and will save you up to $20. Buy spare handles for tools you have on hand when they are on sale or you see a good deal. They don't spoil or go bad. I have handles in my workshop that are over 30 years old and they are as good as new. (I inherited them when I bought the house.)

Wednesday, January 9, 2013

Terra Preta

Certain areas of the Amazon River basin were discovered to be extremely fertile in spite of being in a tropical rain forest area. Tropical rain forests typically have very poor soil because the nutrients are continually leached out by the heavy rains. Why the big difference in these specific areas? The secret is a soil type called "Terra Preta". Terra Preta is artificially amended soil; amended primarily with charcoal. Today we call this amendment "biochar".

What is Terra Preta and Biochar? Biochar is any organic, carbon-based material such as wood, paper, reeds, etc. that is heated in a low oxygen environment until it is carbonized. Charcoal has been made for centuries in outdoor pits filled with wood, lit on fire, and then covered with clay. Today it is cleaner and easier to make it in closed containers (with a small opening to release the flammable gases). Do a Google or Yahoo search on making charcoal if you are interested.

If you have a wood stove, fireplace, or fireplace insert you likely end up with lots of ashes and what do you do with them?  Ashes are good for your garden soil in certain circumstances.  Wood ash can be useful in home gardens, in your compost pile or as a pest repellent.  Wood ash can be a valuable source of lime, potassium and trace elements. Since wood ash is derived from plant material, it contains most of the 13 essential nutrients the soil must supply for plant growth. When wood burns, nitrogen and sulfur are lost as gases, and calcium, potassium, magnesium and trace element compounds remain. The carbonates and oxides remaining after burning are valuable liming agents, raising pH, thereby helping to neutralize acid soils. Ash from a cord of oak meets the potassium needs of a garden 60 by 70 feet, he said. A cord of Douglas-fir ash supplies enough potassium for a garden 30 by 30 feet. Both types of ash contain enough calcium and magnesium to reduce soil acidity (increase soil pH) slightly. In compost piles, wood ash can be used to help maintain a neutral condition, the best environment to help microorganisms break down organic materials. Sprinkle ash on each layer of compost as the pile is built up. Ash also adds nutrients to compost. If used judiciously, wood ash can be used to repel insects, slugs and snails, because it draws water from invertebrates' bodies. Sprinkle ash around the base of your plants to discourage surface feeding pests. But once ash gets wet, it loses its deterring properties. Continual use of ash in this way may increase the soil pH too much, or accumulate high salt levels harmful to plants.

You probably find some charcoal in your ashes too. Charcoal has some interesting properties for improving your soil. Charcoal, finely ground, when added to your soil will hold large amounts of nutrients and moisture.  Charcoal is a fine-grained, porous black carbon, generated from plant materials heated or "burned" in a low oxygen environment. It is non-toxic to plants and people if made from clean, untreated wood. There are many tiny pores in charcoal and the pores will allow air to diffuse into the soil. Plant roots need the air to breathe. The tiny pores will hold water and nutrients and later supply them to plants. More important, unlike other organic fertilizers, charcoal is very stable and it will not decompose to carbon dioxide. So once applied, it will stay in soil for hundreds to thousands of years. The high stability and porosity make charcoal a better fertilizer than most other organic materials.

How much do you want to incorporate into your soil? The general consensus is about five percent by volume. That is far more than you think. So adding small amounts accidentally produced in your fireplace is not going to improve your soil very much, but over time the soil will get better and better. You'll probably need to intentionally produce larger amounts if permanently improving your soil so that you can produce more food is your goal.

I installed a fireplace insert last weekend so that I can partially heat my house with the abundant wood on my property. At the end of the evening I generally close the damper on the insert and that chokes off air to the fire box; this produces charcoal. I will be adding this to my garden all winter long and see how much biochar I can get incorporated into the soil. If it is not as much as I want I will attempt to produce more charcoal using a burn barrel.