Cutting Metal By Hand
I am usually an advocate for using a power tool any time metal work is done. There those times though, when doing it by hand is best. Cutting this 16 gauge aluminum sheet with a hack saw is a perfect example. This thickness of aluminum is rigid enough not to be easily bent or cut with tin snips. Using a angle grinder would be overkill though. This especially considering the special properties of aluminum. One of which is its relatively low melting point of 660 degrees Celsius. The heat from friction could gum up the abrasive cutting wheel. Also, aluminum is relatively soft in comparison to steel so it is much easier to cut.
Setting up for the cut
Setting up to cut sheet metal with a hacksaw is identical to using power cutting tools to cut metal. You draw a line to follow, and if cutting straight lines, use a straight edge to guide you along the line. Above you see I have created a grinder pattern on the sheet metal I will later use in a metal art clock. I used a combination square to draw a rectangle 7 inches wide and 8 inches long. The straight edge I use is a piece of 3/16″ thick angle iron that also serves to hold the aluminum sheet still while cutting. I line up the edge about 1/8″ from the line and clamp down firmly.
The blade for the hack saw should be a metal cutting blade and be mounted with the teeth pointing away from you. This allows for the cutting to occur in the forward stroke and clearing chips and burrs from the teeth on the back stroke. A couple drops of 3 in 1 oil on the blade make a world of difference in keeping the blade from getting caught in the cut and keeping the blade relatively cool. Cutting fluid would work equally as well.
The important thing is let the blade do the cutting and not to force it. The blade will last much longer this way. Also be sure to stay near your cutting guide so as not to stray too far and mess up the straight line.
The Finished Cut
Although it does not look as perfect a mass produced sheet from a big shear, I am pleased with the result. Now it off to design my next clock.
- DIY Gift Ideas: Aluminum Sheet Candle Holders (ext.homedepot.com)
- Cutting Metals (jtbmetaldesigns.wordpress.com)
- Sheet Metal Miami for a Number of Uses! (structuralsteel.wordpress.com)
- Understanding the Sheet Metal Fabrication Process (tiltuppaneldetailing.wordpress.com)