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Hi Glen. The wire James recommended is good stuff and will work fine. The
process of welding a pressure vessel is a little complicated and there are a few
things to keep in mind.
Make sure the groove is very clean and uniform in profile. I would
recommend TIG welding the "root" as this makes a clean beginning for subsequent
weld beads.
Pre-heating the base metal before welding is a good practice. It helps make
strong welds, and minimizes stress build-up.
Use spacers/struts inside the hull to help maintain "round" while you weld.
Using gas coverage on the back side of the weld also helps to keep the weld
clean. A simple box made of sheet metal attached to the back side with tape or
magnets, and filled with shielding gas works well. Just big enough to cover the
section you are welding. Then after laying down the weld bead in that area and
letting it cool down slowly, move the shielding box to the next weld area.
Continue the gas flow to the box until the weld has cooled some what to prevent
oxygen from contaminating the weld bead.
Grind/clean the beginning of each weld where it meets the previous weld.
Most "inclusions" occur at the start/stop zone.
Take your time doing "fit-up" and keep the base clean.
Welder "position" is important too. It's much easier to make a good weld if
you are in a comfortable position. Welding in the "flat" position is best, as
gravity works in your favor.
Practice a little before each welding session, and try to stay comfortable.
It's easier to make uniform welds when the position and machine settings are the
same. Don't get in a hurry. Take your time. Be comfortable.
It will be a very rewarding experience and you'll feel good knowing
your welds are strong. Remember, your life depends on that. Good luck with your
project, and send us some pictures. We love to see the process of a sub being
built. Ask lots of questions, and have FUN!
Frank D. Great deals on Dell’s most popular laptops – Starting at $479 |