Thursday, March 19, 2009

Spring is coming

Sometimes I just can't resist taking pictures of the groceries. The sun was shining through the overhead skylight, which appears to employ a frosted surface. It made for some very nice light against the white tile on the counter top. I got inspired and put this image on a bunch of products right here.

Craft adventures

The pair of scissors on the left were bent and no longer worked as scissors. I heated and unbent the handle near the pivot point using a small Ace hardware propane torch kit; the kind that comes with a 14.1 oz propane bottle. There have been a few "gremlins" in the process; like the first torch I bought didn't have a hole drilled in the end, just a solid brass end. I told the clerk it would make a good practical joke when we returned it. Anyway I put the scissors into a vice and just heated one area until it turned red, then turned off the torch and bent it with a pair of vise grips, but pliers would have worked just as well.
I had intended to straighten out the handles all along, so I just kept heating and bending them back to get the hand loops back and out of the way. Interestingly enough, the handles cooled and became what I would call, grass-stem straight. I wasn't aiming for perfectly straight anyway, but once cooled and when I played with the scissors, snapping them open and shut a few times, the handles started to twist by themselves. Trippy. I had read about how heating and bending metal puts internal stresses into the material as it cools. It was like the steel wanted to go a certain way, and just by handling it a little, when it cooled all the way to room temp it went there. I have also read that in order to deal with this, one has to anneal the steel after working it in order to relieve these stresses. Likely it's even worse than usual because I only heated small sections at a time and bent them rather than heating the entire peice at once (which I can't do yet). Annealing in this case means to take the hardening out of metal by heating it up... and here I will quote liberally from wikipedia:

"Carbon steel is heated to approximately 40 °C above Ac3 or Ac1 for 1 hour; this assures all the ferrite transforms into austenite (although cementite might still exist if the carbon content is greater than the eutectoid). The steel must then be cooled slowly, in the realm of 38 °C (100 °F) per hour. Usually it is just furnace cooled, where the furnace is turned off with the steel still inside. This results in a coarse pearlitic structure, which means the "bands" of pearlite are thick. Fully-annealed steel is soft and ductile, with no internal stresses, which is often necessary for cost-effective forming. Only spheroidized steel is softer and more ductile."

So, getting the true signifigance actually gets taught better by doing. It was pretty fun having steel twist itself into a new shape in my hands, felt like it had a mind of it's own. I did manage to anneal some steel in my flower-pot oven already. People tell me that blacksmithing is a slow process, and I am getting some sense of that.

This started life as a pair of forged scissors from China. I understand you can buy them for about three bucks. From the photo at the very top you can see that they had a very graceful curve to the handles which must have been put there by bending over a form in one motion while they were red hot. My current torch will only heat a small area at a time. I tried to trap the heat by stacking firebricks, but it didn't help much. This after reading about something called a bean can forge . My firebricks are the denser type; they look and feel like sandstone. They appear to absorb a lot more heat than they reflect back. I understand that they last a long time though, and they were only two bucks each. The other type of firebrick which I have seen elsewhere are very frangible, light weight with a consistency sort of like styrofoam. They are reported to have a higher r-factor. I bought the only kind available locally. Oops. There's this stuff called kaowool which potters use; it's a sort of spun-ceramic blanket, then they coat it with some other stuff called itc-100 which is claimed to reflect 98% of the heat energy. I don't have any; the itc-100 is about $30 bucks a pint and I had really intended to do the forge project on a shoestring budget. However wasting fuel would quickly drive up costs, so there's a point wherein being too cheap doesn't pay off. As it turns out the very first thing I wanted to do is called forge welding, where the material has to be much hotter in order to join two peices together. So far I can barely put a dent in metal, let alone weld it.

We've now spoken with a couple of guys who are expert welders. One had a long career doing welded art peices. He doesn't want any publicity because he's retired now. I'm noticing the welders tend not to forge, blacksmiths tend not to weld, and metal casters tend to stick to casting, doing neither welding nor any forge work. Oh yeah, and glass blowers probably don't do much metal forging either, even though they could probably do so pretty easily. Hmmm. One of the local guys with an art metal shop in Show Low mentioned how quickly his computer controlled plasma cutter could perform tasks ( in seconds ) versus hours. Mostly I have been getting a history lesson with all my research into this stuff.

I think we watch shows like "Terminator" because it's such a literal picture of what we're doing to ourselves with technology. A lot of the hand made things you see are made overseas where low-tech labor is cheap enough that you can't beat the final product with a lot of high tech factory machinery. Around here there was a big problem with Native American craft products turning out to be made in China. I think I'm re-working a chinese made pair of scissors
( hand-forged, no less ) to give me more of an appreciation for hand made products. It may be slow and laborious but you learn a lot and it stays interesting. Beats factory work.

Saturday, March 14, 2009

Flowerpot forge that doesn't work, yet.

Bought a set of three nesting flowerpots at the grocery store after getting the idea from another website to build a forge, or possibly a kiln or even a cupola for metal-casting. This is me pretty much seeing what kind of stuff lying around will more or less fit together. This old saw blade might be converted to a tuyere (pronounced tweer ) with some drilling and maybe removal of teeth--or not. Anyway I stuck it in there as-is just to have something for the charcoal to rest on.

So this is two of the three nesting flowerpots with dirt/rocks in between as filler. At the bottom you can see two firebricks that the pots are resting upon, and a small pipe meant to serve as an air inlet to mount a blower to at a later date (if at all). At this point I was just bored with how slowly the project was coming together and I wanted to see if the small air inlet would draft any air into the firepot without a blower. It didn't. The middle sized pot has not yet been utilized. This is just the largest and smallest put together.

I think if this pipe were larger in diameter and did not make a right angle bend, it might work as a barbecue grill without a blower. But then there's still no easy way to dump the ashes. Blower options range from blow dryer to large bellows which would likely have to be hand built, to cast iron hand cranked blowers made specifically for a forge to electric powered blowers costing about $160 also made specifically for a forge. I considered an electric leaf blower, variable speed, but am really trying to keep costs down and even those cost a bit much for me.

This chimney was laying around ( a discard that some unknown potter made and for some reason threw away ) So I though I'd try it out. Here you can see how large the chimney is and that the inlet pipe is way too small.

I knew it wouldn't work too well, but I had an agenda.

Here's me after having stuck a long pipe into the lit "oven" to see what would happen. It did seem to draw better than the shorter chimney, hard to say. The real problem was the inlet pipe being way too small.

Here was my true agenda revealed: Hot dogs! Let a little air in from the top, add a grill and it works-- actually worse than if I had simply piled charcoal on the ground, but it is more aesthetically pleasing than a pile of charcoal on the ground, plus, it's conveniently several feet above ground level.

After all the excitement (food) I decided to put the chimney back on but prop up the bottom for an air inlet, I threw some old dried up juniper in and it burned pretty well.

So here's my disclaimer: don't play with fire, don't do anything that I did, all this stuff is dangerous and if anything get good advice from somebody who knows what they are doing (not me) when it comes to making stuff.

Some things I learned: Dirt and rocks don't insulate very well at all. I also understand that rocks can have moisture trapped inside (especially river rocks) and if you heat them up they can explode, cause injury and wreak all kinds of havoc. Even though I generated very little heat with a small fire, the outside of the pot eventually became borderline too hot to touch. Flower pots aren't sold to be used as an oven either, and might fail when subjected to high heat. Anyway the whole thing stayed hot for many hours after the fire went out, so even though the R-factor must be pretty low, there is enough thermal mass there to retain heat for a long time. That could come in handy. Nothing cracked or blew up so far.

Per the internet; commercial charcoal briquets, the standard barbecue variety, makes for some pretty lousy fuel to build a forge even if you get everything else right. Around here we are somewhat challenged for electricity also (off the grid), therefore using a blower, even something as simple as a blow-dryer is quite wasteful. I was able to anneal a tiny bit of steel in this after I tipped up the chimney, added some wood etc and then let it cool overnight. So, there are some possibilities. I may utilize all three flower pots, the chimney and a very much enlarged air inlet to see what it will do. I may also bury it in the ground in order to retain more heat over a longer time period. In the meantime I have bought more firebricks and a small propane torch and may follow some general guidelines that I have seen online to make a tiny, primitive forge. Why? Propane doesn't require an additional blower, is instant-on and also instant-off, no ashes to deal with, less likelihood of air born sparks, easier to control the draft and flow of heat. . . maybe less fun than charcoal and bellows but my desire to do archaic things has it's limits.

I'm not the type to make my own higher quality charcoal from wood either but I have seen it recommended. Look for Tim Lively on the internet for some truly helpful info and an available video called "Knife Making Unplugged" and there are many other web-sites I have visited for tips and sometimes watching in horror as people very narrowly escape serious injury while fiddling around with very high temperatures.

I made a knife about ten years ago for my mother, but I didn't forge the blade myself-- far from it: I chose a replacement blade for a pair of garden shears from a garden supply store and was surprised to find how poorly it worked as a knife blade. Oh well, won't make that mistake again.
Here's a casual shot the knife I made. The handle is a "found object" oak stick with some complex curves. It feels good in your hand but has not been used much, it literally hangs on the wall. All this is about me trying to emerge more as an artist. I happen to like functional art, and the photography, writing, and even music has never quite satisfied that part of me. I've built speakers as a professional, and an electric guitar in woodshop when I was in the seventh grade which was my main "axe" for several years and I'd really like to get back to more creative works.

Pencil in the foreground is for scale. The circle near the blade is a drilled-out knot-hole which I then filled with aggregate of wood-chips and epoxy to make a sort of artificial knot with better strength. To the left of that is a copper pin made from copper wire which also helps hold the blade in place. Along the top is some copper inlay and there are several holes drilled near the back which join together inside. A loop of cowhide is laced through and knotted thirteen times, as a lanyard. It is very nearly a sort of peace-pipe, but I don't smoke, nor do I have Native American in my genetic make-up, despite some of my attachment to certain Native American rituals and beleifs, and some personal experiences with nature which also lead me in the direction of nature based spirituality. . .

It's a bit difficult for me to give myself permission to do this kind of work, beleive it or not. I don't know why it should be so hard: my family is full of artists, musicians, and other creative folks. Sometimes it seems like I had to hit-bottom financially in order to give myself permission to do the creative work that I love.