Join Date: Jan 2011
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Re: Structural question for you engineering types
The mast is primarily in compression at any location that you can reach. So the holes will be no problem provided they don't give the impression of your run-of-the-mill cheese grater. And, whenever possible/practical, don't weld aluminum for strength. Aluminum actually looses up to 50% of it's strength within 1" of the heat affected zone. I say "up to" because engineers can slant things when calculating stresses (that's why they call it "justifying") so that number can go from 25 to 50. Some alloys that I am not familiar with may have different results but 6061-T6 (and 6063-T...) fall into the category. So don't weld the holes. Steel, on the other hand, often increases in strength at the joint, usually due to the filler rod being 50 ksi material of better. That's why most people consider welding a benefit. If you see an aluminum something with welded joints, it probably isn't structural in nature, more assembly oriented, like building a chair or a work bench frame. If it is structural, a car frame or trailer frame, it will either be an engineered joint or bolted assembly at key stress areas.