Filler Rod (for 4130)

[Ben Beacock]

I've seen that many teams use the ER70S-2 for a 4130 chassis, but licoln and tig-depot recommend ER80S-D2 first and ER70S-2 second. its harder to get and slightly more expensive. what advantage does it give? better elongation? higher strength?

[Ben Beacock]

I've seen that many teams use the ER70S-2 for a 4130 chassis, but licoln and tig-depot recommend ER80S-D2 first and ER70S-2 second. its harder to get and slightly more expensive. what advantage does it give? better elongation? higher strength?

[Lyn Labahn UW-Madison]

Ben, ER80S-D2 has a little bit more strength, at the expense of ductility. For these reasons, and the reasons you mentioned earlier we use ER70S-2. We use it for just about everything steel besides Stainless, and have never had a problem with it. Your welding technique and quality is MUCH more more likely to have an effect on the strength of your joint than the difference between those two rods! Food for thought,

[Ben Beacock]

Thanks for the info,

4 of our team (including me) are enrolled in a friday night TIG welding class at the local college. It should certainly help with the weld quality. Plus we bought a new welder that isn't 40+ years old.

[Lyn Labahn UW-Madison]

Excellent idea! Most of the welders on our team including myself learned by making lots of nasty, bad penetration (heh penetration), rusty, burned through welds, until we started getting something decent. In other words, just lots and lots of practice. You will be surprised how fast you can pick it up if you practice consistantly. Once of the hardest parts of welding in FSAE is that lots of stuff is very thin wall, if you don't have thin wall tube availible to practice with, a lot of places like Wicks Aircraft sell a "box o' random tubes" for a decent price that make good practice.

[Tire Guy]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Lyn Labahn UW-Madison:
...learned by making lots of nasty, bad penetration (heh penetration), rusty, burned through welds, until we started getting something decent.... <HR></BLOCKQUOTE>

Our main welder graduated last year, so we've had a few guys practicing constantly and they are getting pretty good. Some of their welds occationally turn out rusty though. Any of you guys with a bit of welding experience care to throw in your $.02 on why this happens, and what we can do to prevent it?? Thanks a bunch....

[Lyn Labahn UW-Madison]

The rust is caused by the extremely hot, or molten metal coming into contact with the atmosphere and forming oxides. This is due to not having enough shielding gas in the area of your weld. Here are the likely problems:

1. Your gas flowrate is too low
2. You are holding the torch at an incorrect angle
3. After the weld is completed, you are quickly removing the torch from the weld.

After your weld is complete your torch should remain stationary and let the area cool with the post purge of gas the flows from the torch after the pedal has been released.

Also, to ensure quality welds, make sure that all burs, water and grease are removed at least 1/2 inch from the weld area! A good steel tig weld should be nice and shiny, with even beads and no surface porosity. The area around the weld often has a brilliant layer of rainbow like deposits around it. These are removed once you clean the surface of the weld afterwards,
Any more questions, let me know.

[Alan]

I've always found that a gas lens comes in pretty handy. Once you have the basic skills and knowledge I think the two most important things are care of the electrode and joint preparation. Once the electrode is contaminated switch to a new one. Before you start welding clean the area with a wire brush (have one for steels and another for Al) and wipe it down with acetone.

Ben, that TIG class at the local college is an excellent idea. I took an 80 hour course before I got involved with FSAE and it was invaluable.

[Tire Guy]

Thanks for the input guys...I will be sure to pass the information along!