fillet welds with a stick

[BRIAN GALLO]

Hey stick welder's, I have a question. I can weld flat, butt or bevel welds with much success, but I can't get a good fillet weld to save my life! I just can't seem to get the angle or penetration right no matter how much I practice. any pointers???? :rolleyes:

[75]

First off, I'm going to assume we're talking about fillet welds in the flat position.

Actual technique varies a bit depending on the thickness of material and size of weld desired, but the basics are similar: Rod angle should be about as shown in the photo, to keep the two "legs" of the fillet weld the same length. Also have the rod angled about 45 degrees or so in the direction of travel - in this case I am welding from left to right:

[75]

On welds like this I generally don't weave, or weave very little. In the one I did here as a "demo" I didn't weave at all, just ran a straight stringer bead. Important thing with fillet welds is to keep both legs the same length - in a case where two different thicknesses of material are being joined you may have to alter the rod angle slightly to keep a bit more heat on the thicker piece.

When running the bead, remember to keep the travel speed constant. Speeding up/slowing down will change the size of the weld bead.

[75]

If a larger weld is required, use multiple passes to achieve this. I did three passes for the "demo" weld, the first pass I did is called the "root" pass. Here, the second pass is laid down in the "corner" where the bottom leg of the root pass meets the material:

[75]

Third pass goes on up top, and brings the weld back to having equal length legs. For a larger weld, simply continue adding pases in a similar pattern, it will likely be necessary to put 3 more passes on at this stage to keep the fillet legs equal: Bottom, middle, top.

[75]

A common mistake is trying to lay down a large bead in a single pass. This results in "overlap" - along the bottom outside corner of the weld bead it hasn't fused to the base metal. So the portion of the weld that's actually doing something is about the same size as the root pass in the earlier pic.

Hopefully that can be of some help, now if it's fillet welds in the vertical position that can be a little trickier.....................

[75]

.........................but not impossible. Rod angle for vertical up is a little different, as shown here you still want to keep the leg lengths of the fillet equal but instead of being angled in the direction of travel, you want the rod pretty much straight on to the workpiece.

[75]

For vertical up welds, typically you want to use a heat setting in the lower portion of the heat range for the electrode you're using.

Example: for 1/8" rod, the "rule of thumb" of 1 amp per thousandth of an inch of electrode diameter equals 125 amps. For vertical up, try it at 120 and see how it works.

It should be possible to run a stringer bead straight up without having to stop/start or weave it on the root pass, as was done here:

[75]

On subsequent passes, for vertical up I like to weave 'em but you can also run stringer beads in the same manner as the flat fillet weld.

To weave, starting at the bottom you want to get a "shelf" started and work your way up, weaving from side to side and pausing momentarily each time you change direction to fill in any undercut along the edge of the weld. Key here is to be smooth and steady, and avoid "whipping" the rod from side to side real fast. In this pic I have only welded partway up on the second pass so you can get an idea of the "shelf".

And it took a long time for my vertical up to get to this stage so don't get discouraged! Vertical up is challenging, so just get some scraps like the ones shown in the pics and practice away!

FWIW, all the "demo" welds were done using 6013 rod with an AC machine, and I used 3/32" diameter rod. The same principles apply with 1/8" and larger rod - I used 3/32 simply because I was already working on a project and had it out.

[SCL]

Nxt week Prof. 75 will teach us how to... Awesome description and I hung on every word. I am the typical farm welder and have learned a ton from your posts. this one was quite appropriate. How do you find time to post so much info and pictures. Don't stop, I was just curious:)

[75]

Thanks SCL............ :blush: ..................although I can't take too much credit for the "how-to" info: most of it is taken from the welding procedures book that's carried in the work truck. I just re-typed it here................

I bought a digital camera recently for taking progress pics of my current truck project, and I've found it to be super handy for many things such as this. Take a couple of pics, and in minutes they can be posted. Having the ability to "attach file" here at Lawnsite is a b-i-g help too (thanks Chuck! :) ) because pictures make it much easier to describe some things.

One thing to remember too, when doing vertical up welding, is that some electrode types aren't suited for this type of work. An example is 7024 - this is primarily a flat-only welding rod.

6011 and 6013 work well for all-position welding, as does 7018. And remember, vertical down ("downhand") welds are stricly for cosmetic work!

[BRIAN GALLO]

75, thanks for all the info. Those were excellent welds too! I think I am holding the rod in the position you show, but I seem to actually be blowing the weld out of the center right where the 2 pieces of metal butt together??? I end up with a little bit of weld on both pieces and nothing connecting the two. Even with multiple passes my fillets are sloppy at best. I tried lowering the amps and the speed, but I still can't get them as good as yours.

[75]

Couple of items that could be a factor: what thickness material are you welding, and what type of rod are you using?

If it's fairly light material - 1/8" and down - you may still be a bit hot. Lighter material like this is where 3/32 rod can be really useful.

One indication that the welding amps are set too high is excessive spatter - those little blobs of metal that resemble tiny BB's scattered all over the metal.

And, on light stuff it can sometimes help to actually increase your travel speed a little. This way the molten pool of weld metal doesn't have time to blow through the material.

Some welding rod - 6011 in particular - tends to have a "harsher" (for lack of a better term) arc than other types like 6013 and is more likely to burn through on the thin stuff.

Another thing that comes to mind is how clean are the parts being joined? I end up doing a fair bit of repair welding at my work and things like dirt/grease/oil/paint/etc can cause the arc to go all over the place - everywhere except where you want it to!

[BRIAN GALLO]

Thanks for all the info 75. I'll try practicing some more using your tips.