I am about to build a mock-up of a rocket. The only way to attach fins, or so it seems it a spot weld them to the main body, which is a tube of steel. Is there any technique/equipment to do this? As i understand one electrode should go deep inside the tube, and i didnt see anything like this for sale

-- Boris (sposner@excite.com), May 30, 2001

Answers

You are referring to accessory items on standard equipment. Either a special offset holder electrode arrangement or straight mandrel enters the tube to provide weld pressure back-up and complete the weld current path. Other welding, and bonding methods other than resistance welding are available, such as GMAW, Braze, TIG, Laser, etc.

However, the following is some of the information required for us to properly help you:

1 Sketch of the tube and fin arrangement. 2 Tube material and thickness. 3 Fin material and thickness. 4 Distance into the tube that the weld mandrel would need to enter. 5 Inside diameter of the tube. 6 Do you require tooling to align the tube?

Please note that if there is only one unit that you are constructing, may want to evaluate some welding company to perform the welding, renting the equipment, or check into purchasing a used machine.

Good luck with your project.

-- Bob Balla (bobballa@tjsnow.com), May 31, 2001.