I could not work on anything else much today. Outside it is still very windy and the workshop concrete floor was freezing cold even with the fire roaring in the stove. So I could not be there for more than two hours at a time and then I had to go inside to warm my feet for about the same. But I have managed to do something useful – three sets of jaws for my bench vice.
On the left aluminium, then beech wood and then spruce wood covered with an old carpet. I needed these for a long time and I had to do with impromptu padding the jaws of the vice with slabs of these three materials several times on each project. And impromptu padding leads to time loss each time you use it, not to mention the cussing. For a hobbyist making one – two knives per year it is not a big problem, but now…
The dark spots on the backside covered with masking tape are where a strong 6×3 mm neodymium magnets are hidden – they collect the magnetic dust in the shop very quickly. Thus the masking tape. I had eight these magnets for a long time and I had no use for them, so I have used them for this.
And the jaws work very well. The grooves on the alluminium ones might be a bit too shallow for stock thicker than 10 mm, but I am not going to do anything about them just yet, they do seem to work just fine as they are and I will probably need to hold even 3-4 mm stock in them more often than something bigger, so they cannot be too much deeper than they are.
Working with aluminium is a bugger. Whenever I have an urge to file, cut or drill aluminium, I usually sit down quietly in the corner and wait until it passes. But sometimes there is no way around it.
Did I already mention that working aluminium is a bugger? It is worth repeating. It is soft but relatively strong in tension. It is an extremely good heat conductor. And it is also extremely prone to galling and cold-welding. The end result is that it blunts and overheats saws and drillbits and clogs-up files and abrasives.
A few years ago I got a useful tip from a machinist at my former workplace. I complained about how filing and cutting aluminium by hand is more difficult than steel because of the clogging of the tool teeth. I told him that I tried using powdered chalk to coat the file and clean it with a brass brush – a tip from another machinist – to prevent this, but it did not seem to work very well. And this machinist told me “wet your file with alcohol to keep it cool”. And it does indeed help a lot. I still need to keep a brass brush at hand to clean the file from time to time, but the alcohol does prevent the shavings from sticking to it very strongly. And unlike oil, it dries off and does not make a mess, so I use it for drilling aluminium too.
Even so, it is worth repeating. Working aluminium is a bugger.
dakotagreasemonkey says
Charly,
I. too, have a hard time working aluminum. Too soft, too sticky in file teeth, clogs abrasives instantly! I’ve used thread tapping fluids, with partial success. Never thought of using alcohol! You mean “wood” alcohol, not drinking alcohol, I presume. Not wasting my whiskey on a chunk of aluminum!
In future, I’ll give it a try! Thanks for the tip.
lorn says
I learned from an old machinist to keep a file card handy and use it often. Our first project was converting a piece of mild-steel round stock to a sized cube, +/- .001″ with just a chisel, ball-peen hammer, and a single-cut file. Chisel, chisel, chisel. sharpen, chisel some more … then start on another side. File, file, file, card the file, file some more. When you are really, really close start draw filing it to a mirror shine.
I hated it at the time. A few quit entirely. More than a few threw fits, and a couple of hammers, after they learned they needed to start over. Blisters all round. The lessons learned were priceless. How to grind a chisel just right so you can see the steel move with every swing. How the hammer hard without wearing yourself out. How to engage and use the full length of the file to remove metal fast. How you can feel the chisel start to get dull or the file clogged. To maintain your tools early and often to minimize effort and maximize effect. How, when it was all over, we were so proud of our mirror-bright shiny little cubes. How once you had done it once and mastered the technique you could easily do it again in a third the time using the exact same tools.
Funny how any time I restart my hand tool collection I get a new file card with the first files. Chalk can help also. Used it a lot when we filed lead shielding.
For aluminum we used two compounds to make it work easier: LC.Wax -- Aluminum lubricant, and Tap Magic -- aluminum. Both are still sold. I keep a bottle of each handy. Either one made a big difference in machinability, cutting, tapping. I preferred the Tap Magic for milling and the wax for hand tapping. Just a little can work wonders. The aluminum finished smoother and tools lasted longer.
The welders complained about the Tap Magic, claimed it soaked into the pores and made welding more difficult. I don’t remember any complaints about the LC.Wax product.
Who knows. The welders were all stoned, drunk, or both. Damn near to a man they couldn’t weld for shit sober. The exception was a Bible-thumping TIG welder. Who couldn’t weld for shit if anyone cussed, told rude jokes, or if any women were within eyesight. Even the smell of perfume would rattle his cage. Everyone has their issues.
Marcus Ranum says
You can get blocks of polypropylene or delrin on ebay. It’s way easier to cut than aluminum and it won’t load up your cutting tools. I shape it with my table-saw, mostly. It’s just soft enough that it won’t scratch your steel as long as you’re careful to not grind chips into the surfaces.
I saw a blacksmith who modded his post vise with magnets so he could position something and it’d just stay there while he cranked the handle. Very clever. I keep thinking someone needs to make a post vise that works like one of those jaw-horse clamps: hands free.
Felt jaws are ritzy! I usually just put ${whatever} in the cuff of my furnace glove and then put the glove in the vise.
Charly says
@dakotagreasemonkey, I personally wouldn’t mind using even whiskey since to me it is about as drinkable and tasty as turpentine :-), but that is a matter of personal taste. However denatured alcohol is 1) cheaper, 2) has lower water content and dries quicker. So I use that.
Giliell says
I have nothing sensible to add, but I like that expression:
Because I frequently find myself in the middle of something where I question my sanity and ability to make decisions.