Welding Tips and Tricks

hi all!

my son is in the process of building a back half-ed drag car, and is building the chassis from scratch. using a hobart 210 (240v) with 75/25% mix .035 wire. frame tubing is 2x4 .120 wall. round tube is .120 wall. would like some opinions, and guidance on the welds from the experts. no cage yet on order. will be 12pt. and still plan to gusset the seams where the chassis comes together, but dont want a failure either since this will also be a street car making good power. it all layed pretty flat.

these 2 i think i should have burned the horizontal welds a bit hotter. and as for the bulky spot, i was afraid i might have undercut it a bit, so i filled it in. **

Vette76,
Welcome to the forum! Looks like a great project to me, would like to see more of this one.
To try and answer some of your questions, those first two welds actually might be to hot and have improper gun angle. You should/might be able to use the same settings just aim the gun up more at the top of the joint and a slight whip will help you. These welds will hold they just might not look very good. One concern I have is in pic 4728 your vertical down has no root reinforcement from the fact it was welded down. While it might be overkill and some might not agree, I would try to run what I could vertical up to get your penetration and a thicker throat. One argument against this would be it is 1/8" plate and falls in the guidelines for a vertical down. Also turn the heat down if you are going down like that. You can actually have cold lap because you are just melting metal down that joint and possibly not penetrating. Also in 4718, you have some serious cold lap or lack of penetration on the sides of the weld. As a whole the welds look great. Don't take any of this wrong as it is meant to help. When you are going a buck fifty down the 1/4 mile you don't want to wonder if the welds will hold if you hit the wall.
-Jonathan

Superiorwelding wrote:Vette76,
Welcome to the forum! Looks like a great project to me, would like to see more of this one.
To try and answer some of your questions, those first two welds actually might be to hot and have improper gun angle. You should/might be able to use the same settings just aim the gun up more at the top of the joint and a slight whip will help you. These welds will hold they just might not look very good. One concern I have is in pic 4728 your vertical down has no root reinforcement from the fact it was welded down. While it might be overkill and some might not agree, I would try to run what I could vertical up to get your penetration and a thicker throat. One argument against this would be it is 1/8" plate and falls in the guidelines for a vertical down. Also turn the heat down if you are going down like that. You can actually have cold lap because you are just melting metal down that joint and possibly not penetrating. Also in 4718, you have some serious cold lap or lack of penetration on the sides of the weld. As a whole the welds look great. Don't take any of this wrong as it is meant to help. When you are going a buck fifty down the 1/4 mile you don't want to wonder if the welds will hold if you hit the wall.
-Jonathan

unfortunately the majority was welded vertical down. i just never knew it was wrong until i started these posts. will it be a major problem? nothing exceeds 1/8" so far. and the 4728 grey wall is actually a tad thinner. it is plated over the rocker panel.
can you more explain the cold lap and lack of penetration you see? i am unclear.
i appreciate it!!

vette76 wrote: can you more explain the cold lap and lack of penetration you see? i am unclear.
i appreciate it!!

I saw the same thing, the bead looks to be sitting on top of the material and the toes did not wet in - general indicators that the plate was too thick for the settings, no gap was used, or no bevel was used (or a mixture of these conditions).

Sounds like a cool project

aha! i see what you are talking about. correct indeed. looks like the ends got hot enough, but the center is indeed like that. i think i will grind them down, and turn the heat up.
thank you!

vette76 wrote:aha! i see what you are talking about. correct indeed. looks like the ends got hot enough, but the center is indeed like that. i think i will grind them down, and turn the heat up.
thank you!

Dave,
Thanks for helping out on this one!

Vette76,
I would like to clarify a few things first. Vertical down is not wrong in itself. I would not go over 1/8" on vert down that are important in any way. Where you get in trouble is if you are welding down on 1" plate at any setting and you will NOT get any penetration. I have busted and cracked joints welded this way. Don't want you to think you cannot weld your frame down at all. Again I would go up, especially if you are new to the welding game, although up has its own challenges.
Second, I don't know if you worded it backwards or I am just not getting it but you stated above that "the ends get hot enough but the center is indeed like that" I assume you mean that the edges of the welds are good and the middle is bad? If that is not the case ignore the next part. The edges have lack of fusion and the middle looks good. As Dave mentioned this is caused by to thick a plate or not hot enough. I will add to this and say your voltage is to high. For 1/8" material the other welds look fine which leads me to believe the volts are to high on the flats. Two ways to fix and both lead to the same result. Either turn up your wire speed, increasing your amperage or turn down your voltage to match your set wire speed, lowering your amperage but putting it where your wire will support.
There are websites I can give you that will do a better job of explaining if this doesn't make sense.
Hope this helps, anymore questions post them up!
Also can you give us your specs on these welds!
-Jonathan

oh, sorry! when i said the edges looked ok, i meant at the very bottom of the plate (maybe the first 2-4" up) and the very top of the plate. (not shown) i realize where i went wrong with the arrows in the above pic. as for specs on the welds do you mean my settings? 75/25 @25cfh, .035 solid wire, 5/40 settings is what i used on most from what i remember. (hobart 210 on 240v.)
i also forgot to say that these plates, and actually 3/16" so i guess not EVERYTHING was .120 wall. i only just realized it when i went to take a closer look.