welding-safe?

[Bloody_Sorcerer]

Hi, me and a friend are considering either doing dry ice or LN2 on his old thunderbird. we will probably be doing DICE if either, unless I can get access to my school's LN2. Anyways, would it be OK to weld the copper tube to the base? Everywhere I've seen people brazing them, but would welding work?

[nbradley88]

good question i was also wondering about this... because a friend of mine owns a cnc shop and he asked i knew if he could tigg or migg weld it... told him i didnt know... but its something to wonder about maybe some of you veterans could give a lil suggestion... by the way if anyone has any solidworks or autocad designs for and DD blocks or anything it would be sweet to get my hangs on one thnx... im gonna get into but i was just wondering if anyone already had one... later :toast:

[Bloody_Sorcerer]

the reason i want to know is because my friend recently got an arc welder for his birthday (off of ebay) and we want to know if it would be useful for a DICE/LN2 container.

[JSU]

arc welding doesnt work on copper. There isnt enough resistance for the metal to get hot. I dont know about torch welding but would assume it doesnt work either.

[Bloody_Sorcerer]

ah, ok, thats what my friend had heard; the copper was too conductive to be welded. Darn! thanks :)

[sang]

an acetilene torch shoud be just fine for welding the CU pipe to the CU block/base.Ive done this myself and it works with ln2 really sweet :) Just use tin(SN,melting point 231.89°C) to solder the 2 CU parts.

[cold_ice]

This is soldering...
You should braze LN2/DI containers, the one I soldered was leaking after some time. The brazed containers don't have a single problem at this low temps ;)

[chilly1]

sta brite solder is ok, 15 % silfoss is stronger and for best if you have a tig and the rods for copper then tigging is really the best answer.

[Stewie007]

Forget welding. Braze it with phos copper and it'll hold up like a solid copper tube.