Jigsaws Can Cut Straight With a Guide
Talk about jigsaws to anyone and immediately they will respond with comment on how it can cuts curves. In general, this is pretty much true. It is difficult to get a jigsaw to make reliable straight cuts over and over. The exception to this rule requires a specially made jig. Cutting metals with a jigsaw can produce some of the nicest cuts. So I made the jig pictured above mostly from scrap wood. You can make one from steel but it will be real heavy and a pain to drill all those holes. Essentially I started with two 18 inch long 5 X 2 boards. I also had some 2 X 2 so I can bond the support table with the clamping table. There is also a 2 X 2 screwed to the bottom of the heaviest side of the fixture for securing the whole thing in a bench vise. I cut off two ends from a 2 X 4 to make two stops. An eighteen inch piece of 1 inch angle iron is the brace that holds down the sheet metal. The magic is in the toggle clamps I bought from amazon mounted so they clamp down on the angle iron holding the sheet metal in place. Once I looked it over, I realized that I mounted the clamps too close together.
I moved one of the clamps over a few inches. I may build a bigger jig for cutting larger sheets but I really do not like the idea of really long cuts with a jigsaw in metal because it takes too long. So anyways, this little fix only took five minutes. At least I can get sheets in there if one of the dimensions is 6 inches or less.
Simply Clamp Metal and Line up Cut
The clamping table and the support table are spaced 2 inches apart. I have a Bosch jigsaw and the distance from the blade to the edge of the shoe is one and a half inches. The idea is you clamp sheet metal down under the angle iron when the cut you wish to make lines directly up with the blade when the shoe of the jig saw rest against the iron. Turn on the saw anc make sure it stays against the angle iron fence.
If the sheet is really thin material then maybe you will need to clamp it down to the support table also to keep vibration to a minimum. Having a welding table that has an open top makes setting my saw aside convenient while I line up the other cut.
After a long evening of cutting, I finally got the raw pieces from my first project with this jig. These are 4 hexagon shapes I will be using to make a decorative wall clock.