Re: What type of aluminum is used for boat tops?
Most aluminum conduit is made of 3003 aluminum and melts at a much lower temperature. In addition, the conduit is softer and will eventually crack under heavy pounding. One of the most important reasons for not using the MIG process is it continues to pile up filler when you may want only to flow out the weld. On top of that, MIG welding will usally leave a pin hole in the weld some where and eventually through condensation, water will get inside the pipe and it will corrode with the presence of salt air. This then makes it extremely difficult to weld or repair at a later date. Precise MIG welding of aluminum pipe takes a great deal of skill to do well and a machine that has a great deal of heat(300 amp plus capacity) Small alumiminum TUBE(not pipe) can be welded with MIG successfully. Upper limits of most small MIG welders will be probably 1" TUBE not PIPE. And PIPE is what you are supposed to use for tee tops, hard tops, tuna towers.... excetra. TIG units CAN be rented for avery cheap rate and are very easy to use and the only consumable is the argon gas. ONe 120 cu.ft./ bottle can do about 10 hours welding in the shop and cost only 40 bucks or so. The 5356 3/32 filler rod is sold by the pound and cost about 10.00 per pound. Do not use 4043 filler TIG or MIG for hard top or t top construction. Aluminum IS EASIER to weld than steel......
