Welding filler rod selection?

by Wayne

So far well happy with a lot of the frame building information. As far as filler rod is concerned, I plan to tack the frame from start to complete frame on jig then do all final with tig welding.

Now my question is which filler rod for cold drawn seamless? 3/8 wall thickness 1.5 od, reason asking as all know for roll cages etc some degree of flex required to avoid stress cracks. Does the same apply for bikes?

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Oct 09, 2014
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Rod size for 3/8 wall.
by: Donald E. Schrickel

I would use 3/32 + P followed by 3/32 7018 to fill it out. Good luck!

May 10, 2013
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filler metal
by: The16oz

Any 70seris wire will work if your welding mild carbon steel. But ER70s-6 would be the wire I would use it runs a little cleaner then the
ER70s-2 it seems to create less sillica. And I would use 1/6" wire to 3/32" depending upon gap needed to fill.

May 02, 2013
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How to do it.
by: Donald Schrickel

3/32 6010 (5p+) rod to start. Then use multiple passes of 7018 low hydrogen Use as many passes as required to build up surface to equal wall size! Good luck!

May 02, 2013
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How about filler rod diameter?
by: Nero

Which rod diameter do you suggest for 3/8 wall thickness? And single or multi-pass?
Many thanks guys, have a nice day!

Apr 18, 2013
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thanks
by: waynetha

Appreciate the answer and have to say it's nice to see more experienced welders giving good advice. Well done and thanks. For the other answer, steel in frame, cold drawn seamless is from carbon rod pushed through a die to form the tube. Hence carbon steel. Thanks again to both.

Apr 17, 2013
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steel
by: route69

You used steel in the frame? If carbonsteel, it's er70xx.

Apr 17, 2013
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ER70s2 Tig Wire
by: Custom-Choppers-Guide.com

The common tig wire for carbon steel is ER70s2. I welded pipe in refineries and petro-chemical plants (ASME B31.3) and that is what we used on all the carbon steel pressure piping.

The problem with the "flex" is more in the Heat Affected Zone (about an inch on each side of the weld). The heat from the weld changes the metal chemistry (grain structure) making the HAZ different and creates a point where the stress is not uniform with the rest of the tubing.

The idea is to get the weld finished, not dally around with it. Good metal preparation, a perfect fit up, and when multipassing, let the weld cool just a little between passes. That also helps prevent undercutting on the final pass.

Girth welds are very strong, especially 1.5" with a 3/8" wall thickness. With good weld technique, it shouldn't be a problem.

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