Passing the AWS D1.1 SMAW 3G & 4G Combo Welding Certification.

This is the second part of the AWS D1.1 SMAW 3 & 4G combo welding certification. I already passed the AWS D1.1 SMAW 3G welding certification and now I am taking the 4G welding certification. Just like the 3G welding certification it is very similar. I have taken pictures to document my results and to give anyone interested a visual understanding of this welding certification is done.

AWS D1.1 SMAW Welding Certification Procedure Specifications

The AWS SMAW 4G welding certification procedure specifications are almost identical to the AWS SMAW 3G welding certification procedure specifications. This certification is very similar to the 3G welding certification with a few exceptions. The first main difference is that the AWS D1.1 4G welding certification certifies you to do fillet welds in the 1F, 2F, 4F, positions, and groove welds in the 1G, 2G, 4G, positions, but it does not certify you to weld in the 3F and 3G positions. By taking the 3G and 4G welding certifications together, it certifies you to weld plate in all positions, and to do fillet welds on pipe with a minimum diameter of 24 inches. When taking these certifications together it also put them into a single procedure. The other main difference is more customary then a procedure specification that involves horizontal and overhead welding. When doing horizontal and overhead welds they are typically done in stringer beads verses flat and vertical welds using weave welds.

The 4G welding certification also comes in two thick nesses. The first is the 3/8 inch limited thickness procedure. This is the one I am taking. The second is the 1 inch thick plate and it the unlimited thickness procedure. The limited thickness procedure certifies a welder to steel between 1/8 to 3/4 of an inch thick steel.

The 4G welding certification also has the same expiration time period. That is if you do not weld using shielded metal arc welding in the overhead position it will expire worthless in 6 months or a 180 days. The welding certifications must be kept up to date with either an employer signing the welding log in the back or simple take a refresher course at a welding school and have them sign off on the procedure.

Welding Certification Procedure Specifications

Welding Process. SMAW Joint Type. Butt Backing. Yes Backing Material. ASTM A36 Root Opening. 1/4 to 5/16 Grove Angel. 45 degrees Back Gouge. No Base Metal. ASTM A36 Type or Grade. Steel Thickness. Groove. (in) .375

Filler Metals AWS Specification. A5.1 Filler Metals AWS Classification. E7018 Electrode Diameter. 1/8 Amps. 90 to 140 Electrode Characteristics Current. DCEP Shielding Electrode Flux (class). 4 Stringer or Weave. Either Multi-Pass or Single Pass (per side). Multiple Interpass Cleaning. Mechanical or Wire Brush

SMAW Welding Machine Set-Up

The 4G procedure just like the 3G procedure states that the SMAW welding machine needs to be set within the range of 90 to 140 amps. I used the same Miller Dialarc 250 welding machine, setting it at a 116 amps like my 3G welding certification. When setting up my machine on a practice bevel I found this setting to be just right. On the root and fill pass I was able to do a weave and on the cap I did stringer welds. As for my stringer welds I needed the machine to run hot enough for the rod to be literally pushed into the metal without sticking. When I weld overhead with a stick welder I typically just start the arc and then shove the rod into the joint. I let the rod burn on its own rate without any manipulation. Literally I do not move my hand and just lean on the rod letting it do all of the welding. This technique works well but requires the machine setting to be hot enough that the electrode has no chance of sticking. Just playing around with the settings I got the 1/8 E7018 electrode to weld at a 140 amps in the overhead position and put down a nice weld. The down side of this is if your electrode angle is off just a bit you will get arc blow. I am mentioning this because many new welders who try to weld overhead assume that you want the amperage to be on a lower setting. The reality of overhead welding is that the hotter the welding machine settings are, the easer to weld. Its more psychological factor

Preparation of the SMAW 4G Test Coupons

Unlike the 3G welding certification were I took a lot of pictures. I did get caught up in the moment of taking the 4G welding certification and forgot to take many key pictures. Unfortunately this is the real test and there are no retakes while doing it!

The preparation of the 4G test coupons is the same as the 3G procedure. These are the AWS D1.1 notes for the 4G SMAW procedure with pictures:

Here are the test coupons and this is how I received them.

I grinded all of the mill scale off of the front of the bevel a minimum of 1 inch back and also did the same for the back of the bevel. . Then I grinded the bevel to get rid of all oxidation. That was followed by rechecking of the bevel angle. Again each bevel was exactly 22.5 degrees and it was inspected. Here is why it was done in this order:

1. Grind all hot roll scale adjacent to the bevel, 1” on the front and ¼” back side of the test plate. 2. Grind off all oxidation on the bevel to bare metal. Re-check the bevel angle for the correct angle. 3. Grind all the hot scale off the backing bar to clean metal. 4. The inspector will check the preparation before fitting-up test pieces.

The bevels were tacked together, the root opening was set with two 1/8 electrodes, and then the plates were inspected.

5. After the fit-up is completed the inspector will check all the fit-up specifications

I put the test plates into the overhead position and they were inspected and marked with a white marker. This is done so the plates are not moved in any way while welding or grinding.

6. Now the test will be placed in the fixed position. The test piece will be marked in position with a marker and the inspector may see the test anytime during the testing. (DURING THE TEST, THE PIECES SHALL NOT BE MOVED IN ANY DIRECTION AND OR REMOVED FROM THE TESTING PLACE WITHOUT THE INSPECTORS APPROVAL.)

SMAW 4G Certification Welding Techniques

The Root Pass

To start the root pass I positioned myself in a way that I can weld toward myself. The first picture is exactly my view from behind the helmet while I am welding. The root took two and a half E7018 electrodes and had two restart. I did a weave technique holding the sides of the bevel until the arc of the electrode would roll and washes into the bevel. If I remember correctly I held each side for about one second. The second picture is the first root weld with the slag covering. Once I put in the root I cleaned it with a chipping hammer and wire wheel. The root was then inspected because the procedure stated:

7. The root pace shall be inspected.

This is where I forgot to take pictures. After that I did a light grinding of the root to ensure there were no slag inclusions and that is in the third picture.

Fill Pass

Before doing the fill pass I let the plate cool till I could barely touch it with my bare hand. On the fill pass I used a wide weave technique holding the sides briefly. It took six E7018 electrodes and five restarts. Since the fill pass came almost to the top of the bevel the slag just popped off by itself and all I had to do is just go over it with a wire wheel.

The Cap and Cover Pass

Before welding the cap I let the plate cool until I could touch it. When welding the cap I used stringer beads. The technique I used was just start the arc and shove the rod into the joint. There was no manipulation of the electrode or any hand movement. I literally let the rod do all of the work! The way this works is the rod is pointed away from you on a 15 degree angle and as the rod burns all you do is keep applying pressure on it till the weld is finished. This is how I typically do most of my welds outside of a welding certification. The cap took four electrodes and had no restarts. To clean the slag all it took was just a light tap with a chipping hammer and it came off. After I finished the cap I cleaned it with a wire brush.

I inspected the cap while still in position and noticed a few spots that had excessive weld reinforcement. I took a 1/8 electrode to measure the height of the weld and marked a few areas that I needed to grind. I grinded the excessive weld reinforcement until the 1/8 electrode was even with the height of the cap. I did this because the welding procedure states:

“The face of the weld shall be flush with the surface of the base metal, and the weld shall merge smoothly with the base metal. Undercut shall not exceed 1/32 in. (1 mm). Weld reinforcement shall not exceed 1/8 in. (3 mm)”

Most welding certification procedures allow one repair to be given after the weld is inspected. Once the test is inspected and you do a repair there are no more fixes after that. This is a perfect example of why you should inspecting you own welds. If you find something wrong and fix it, it is fine, but don’t expect to get any slack if someone has to do your job. With a welding certification after the first inspection that second repair needed results in total test failure. And no you do not get to bend it! Don't take this like you are allowed to do many repairs. If your welds need a lot of repairs and the inspector notices you struggling you may fail on the spot. Not all welding procedures allow repairs or even the use of a grinder or wire wheel!

Preparation of the Test Coupons

The test coupons were pre paired exactly like my 3G welding certification. I marked the test specimens, cut them on a band saw, took a punch and marked the center of the welds, removed the backing bar, and grinded down the root and face to the thickness of the test material.

The Bend Test

The first bend done was the root bend followed by the face bend. Both pieces passed and I did not need the alternate. As you can see below the test coupon were not completely clean. I had a few minor defects that were well within the AWS D1.1 acceptance criteria. The openings were less then 1/32 of an inch so they did not count as discontinuities. I asked why these pieces had these openings and I was told these are common when using weave techniques.

Here are the acceptance criteria for the bend test in the words of the American Welding Society.

“Acceptance Criteria for Bend Tests. The convex surface of the bend test specimen shall be visually examined for surface discontinuities. For acceptance, the surface shall contain no discontinuities exceeding the following dimensions: (1) 1/8 in. (3 mm) measured in any direction of the surface

(2) 3/8 in. (10 mm) – the sum of the greatest dimensions of all discontinuities exceeding 1/32 in. (1 mm) , but less than or equal to 1/8 in (3 mm).

(3) ¼ in. (6 mm) – the maximum corner crack resulting from visible slag inclusions or other fusion type discontinuities, then 1/8 in. (3 mm) maximum shall apply

Specimens with corner cracks exceeding ¼ in. (6 mm) with no evidence of slag inclusions or other fusion type discontinuities shall be disregarded, and a replacement test specimen from the original weldment shall be tested.”

Here are the results of the bend test. As you can see there are some minor openings but well within the acceptance critera.

Passing the AWS D1.1 SMAW 3G & 4G Combo Welding Certification.

This is about passing the AWS D1.1 3G SMAW welding certification, followed by the AWS D1.1 4G SMAW welding certification. The purpose of this web page is to help anyone out there who is about to take these tests understand the welding procedure, and help give them a visual understanding of this welding certification. As the old saying states, a picture is worth a thousand words!

Why Take the 3G and 4G SMAW Combo Welding Certification?

Since shielded metal arc welding is the process preferred for most outdoor work, it makes sense to have these two welding certifications. The 3 and 4G combo welding certifications, certify you to weld in the 1F, 2F, 3F, 4F positions, and the 1G, 2G, 3G, 4G positions, on structural steel. It also certifies you to do fillet welds on pipe with a minimum diameter of 24 inches. Originally I was going to take the AWS B2.1 SMAW 6G open root welding certification, but at the moment I am quickly running out of time, and money to take a risk of a harder exam. Plate is very easy to prepare compared to time involved in setting up pipe coupons. The 3G and 4G combo welding certification are the next best thing and are easy to pass. These welding certifications can be used for most industries and should be the bare minimum for anyone who is going to welding school! If you are in welding school don’t get tempted to leave school with just a 3G welding certification! Yeah you could get a job with just a 3G welding cert, but going back to school later is not that easy!

AWS D1.1 SMAW Welding Certification Procedure Specifications

The AWS D1.1 SMAW 3G welding certification by itself certifies a welder to weld in the flat, horizontal, and vertical positions, without taking the flat and horizontal welding certifications. When combined with the 4G welding certification this certifies you to weld in the flat, horizontal, vertical, and overhead positions, including pipe that has a minimum diameter of 24 inches.

This welding certification comes in two thick nesses. First the 3/8 inch plate and the second is a 1 inch plate. The test I am taking is the 3/8 inch plate test and it is the limited thickness procedure. It certifies you to weld plate from 1/8 to 3/4 of an inch thick. Personally if I had a choice, I would go with the one inch thick procedure. The 1 inch thick plate is an unlimited thickness procedure, but the school I am certifying at does not offer that procedure.

As with most welding certifications the AWS D1.1 SMAW 3G certification does have an expiration date. This welding certification is valid for 6 months, or 180 days, and if the welder does not weld with this process for six months, it expires worthless. On the back page of the welding certification there is a log table for either an employer or welding school to sign every six months. This provides documented proof that you have been using this welding process you are certified in.

Welding Process. SMAW Vertical Progression. Up Joint Type. Butt Backing. Yes Backing Material. ASTM A36 Root Opening. 1/4 to 5/16 Grove Angel. 45 degrees Back Gouge. No Base Metal. ASTM A36 Type or Grade. Steel

Thickness. Groove. (in) .375 Filler Metals AWS Specification. A5.1 Filler Metals AWS Classification. E7018 Electrode Diameter. 1/8 Amps. 90 to 140 Electrode Characteristics Current. DCEP Shielding Electrode Flux (class). 4 Stringer or Weave. Either Multi-Pass or Single Pass (per side). Multiple Interpass Cleaning. Mechanical or Wire Brush

SMAW Welding Machine Set-Up

The procedure states that the SMAW welding machine settings for the 1/8 inch E7018 electrode need to be within the range of 90 to 140 amps. The machine I used was a Miller Dialarc 250 set at about 116 amps. This is the amperage I was most comfortable with when I set my machine on a piece of scrap metal welding vertical up. To get this setting I set the amperage range on 35 to 155 range, and then fine tuning the dial to 6 3/4. This amperage is figured out by using the amperage range of 35 to 155. Then taking the higher number, minus the lower number, (155 – 35) and you get 12 amps. The dial setting I am using has a range of 1 to 10; each number on the dial is worth 12 amps. So the starting amperage is 35 amps and then you multiple 12 by the number that the dial is set at. In my case the dial is set at 6 ¾ X 12 = 81 amps, plus the starting range of 35. That equals 116 amps. There is no right or wrong setting for this procedure, as long as you are within the procedure specifications of 90 to 140 amps.

Joint Preparation for the SMAW 3G Welding Certification

The procedure states in the notes how to prepare the test coupons. Here are the AWS D1.1 notes for the 3G SMAW procedure:

1. Grind all hot roll scale adjacent to the bevel, 1” on the front and ¼” back side of the test plate.

2. Grind off all oxidation on the bevel to bare metal. Re-check the bevel angle for the correct angle.

3. Grind all the hot scale off the backing bar to clean metal.

4. The inspector will check the preparation before fitting-up test pieces.

5. After the fit-up is completed the inspector will check all the fit-up specifications

6. Now the test will be placed in the fixed position. The test piece will be marked in position with a marker and the inspector may see the test anytime during the testing. (DURING THE TEST, THE PIECES SHALL NOT BE MOVED IN ANY DIRECTION AND OR REMOVED FROM THE TESTING PLACE WITHOUT THE INSPECTORS APPROVAL.)

7. The root pace shall be inspected.

8. Required temperatures. ASTM A36, 1/8” to ¾” thick base metal. Minimum preheat and interpass temperatures shall be as follows. When the base temperatures is below 32 degrees, the base metal shall be preheated to a minimum of 70 degrees and the minimum interpass temperature shall be maintained during welding.

As the AWS D1.1 3G SMAW procedure memo states I did the following:

This is how the test coupons looked before any gringing or tacking.

This is a picture of the mill scale grinded back a minimum of 1” on the face of the bevel, with the oxidation on the bevel grinded to bare metal, and the backing bar grinded to bare metal.After that I removed the mill scale a minimum of a 1/4 of an inch off of the back side of the bevels.

Each right on the mark of 22.5 degrees for a total of 45 degrees. The procedure states the total bevel angle needs to be between 45 degrees and 55 degrees. I am well within the tolerance of the procedure. They are inspected and I get to go to move on.

The pictures below are of how I set-up the test plates. First I tacked one side of the bevel to the backing bar. When one side is tacked I used a vice to make sure the bevel is sitting flat on the backing bar. The root opening is set using two 1/8 welding electrodes. I simple put two 1/8 welding electrodes in the root opening, and when I could slide them past each other with just a slight scrape at the tightest point, the root is set to the proper width.Once I set the root opening and have one side tacked, I use a vice to clamp down the bevels to the backing bar and tack it into place. Finally I tacked the middle of the plate to the backing bar using the vice again. This is done to keep the backing bar flat against the bevel.

Pre-Inspection of the Beveled Test Plate

The plates are put into position and inspected. The arm holding the plates is marked in many places to ensure I do not move the test coupon when welding or cleaning.

How to Pass the AWS D1.1 SMAW 3G Welding Certification

The Root Pass

Starting the root weld did not require a preheat as the temperature was about 70 degrees outside. To start the root I got comfortable and started to weld. The technique I used was a side to side weave. I hold the sides of the bevel where the bevels edge feathers into the backing bar until I could see the arc of the electrode start to roll to that side. Once the arc is rolled and the flux is burned off on that side of the electrode, I weave onto the other side, and keep repeating that process. By allowing the arc to roll on the electrode it penetrates the bevel and gives the electrode a chance to ride up on the bevel for a moment. This helps to avoid slag inclusions. I used three welding electrodes and had two restarts. The root weld was cleaned with a wire wheel and as the procedure states it was inspected.

This is done because it is in the welding procedure and in the words of the American Welding Society:

“The root of the weld shall be inspected, and there shall be no evidence of cracks, incomplete fusion, or inadequate joint penetration. A concave root surface is permitted within the limits shown below, providing the total weld thickness is equal to or greater than that of the base metal. The maximum root surface concavity shall be 1/16 in. (1.6 mm) and a maximum melt-through shall be 1/8 in. (3 mm)”

Before moving onto the hot pass or filler pass, I let the plate cool till I could almost touch it with my hand. Second I did take a grinder and lightly grinded the root pass. I did not need to do this, but why take a chance! Here is the root weld grinded.

Fill Pass

For the hot pass or fill pass I used the same technique as the root weld. That is holding the sides and rolling the arc until the weld rides up onto the side of the bevel. I used four electrodes and had three restarts.

Again I waited for the plate to cool and lightly grinded it down. I did not have to grind it, but why risk getting a slag inclusion. As you can see the first restart was a little rough.

Cover Pass and Cap.

The cap was done using a weave technique holding the corner of the bevel until it was filled and the moving onto the other side. If you do not wash weld properly into the corner of the bevel you run the chance of not penetrating the test coupon properly. On the cap of the weld I used four electrodes. Here are the picture of the cap weld.

Here is where I held the electrodes when weaving the cap of the weld. As you can see the center of the electrode needs to be directly on the corner of the bevel. This gives the cap good penatration into the test coupon and keeps the risk of a face bend break to a minimum.

This is the finished weld and cleaned with a wire wheel. It is well within the acceptance criteria. In the words of the American Welding Society:

“The face of the weld shall be flush with the surface of the base metal, and the weld shall merge smoothly with the base metal. Undercut shall not exceed 1/32 in. (1 mm). Weld reinforcement shall not exceed 1/8 in. (3 mm)”

How to Prepare Test Coupon for the Destructive Bend Test

Preparing test coupons for a bend test is not difficult but it does require taking your time and doing it right. There are a few steps that need to be followed otherwise you may fail this test based on preparation!

Test Coupon Marking and Cutting

It is now the next day since taking the test and the plate has had more than enough time to cool

The first thing is to put a mark in the center of the plate with soap stone. Then you need to put a mark one inch above it and one inch below it. Then the next marks are 1½ inches above the top mark and again 1½ inches below the bottom mark. The two outside marks are the bend specimens. Using a square I marked lines across the test plate as to where they will be cut. In the case of coupon failure the middle of the plate can be used as a backup coupon, as long as the failure of the bend falls within the AWS acceptance criteria for a bend test.

Next my initials are inscribed, and the bend test specimens are marked, one for a root bend, the second for a face bend, and the third for an alternate. Just as a not the bend test specimens must be a minimum of 1 1/2 inches wide.

Once I marked the cut lines, I cut them with a horizontal band saw.

Backing Bar Removal

Now it is time to remove the backing bar off the test specimens. I did this by grinding the area where the root penetrates the backing bar. I grinded just close enough to where I could lock on to the split backing bar with a vice. Then I put the backing bar into the vice with one side of the backing bar locked and pushed down with my hand on the coupon like a lever.

The backing bar came off very easily. In my previous welding certification I used a chisel to remove the backing bar. Unfortunately with a chisel you run the risk of gouging into the test specimen. I personally think using the vice was a lot easier then using a chisel. I repeated this until the entire backing bar was removed.

Weld Reinforcement Removal

Before grinding down the root and cap of the weld I took a center punch and marked the center of the weld. This is done to make sure the weld area is what is being bent. Next I grinded down the root and face of the weld until they were the thickness of the test plate. Followed by sanding the corners, and a light brushing with a buffing wheel, this was done to see if there was anything hiding under the surface. As a note if you grind below the surface of the test coupon the test will automatically be rejected!

The Bend Test

I will have two bends done. The first will be a face bend and the second will be a root bend. In the case of a failed bend test, I can still use the center of the plate as a backup coupon, as long as it falls within the acceptance criteria.

Here are the acceptance criteria for the bend test in the words of the American Welding Society.

“Acceptance Criteria for Bend Tests. The convex surface of the bend test specimen shall be visually examined for surface discontinuities. For acceptance, the surface shall contain no discontinuities exceeding the following dimensions:

(1) 1/8 in. (3 mm) measured in any direction of the surface

(2) 3/8 in. (10 mm) – the sum of the greatest dimensions of all discontinuities exceeding 1/32 in. (1 mm) , but less than or equal to 1/8 in (3 mm).

(3) ¼ in. (6 mm) – the maximum corner crack resulting from visible slag inclusions or other fusion type discontinuities, then 1/8 in. (3 mm) maximum shall apply

Specimens with corner cracks exceeding ¼ in. (6 mm) with no evidence of slag inclusions or other fusion type discontinuities shall be disregarded, and a replacement test specimen from the original weldment shall be tested.”

The test coupons are put into the bending machine and bent.

Root Bend

Here is the speciman for the root bend, followed by the bending, and finally sucessfully passing the root bend test.

Face Bend

Here is the speciman for the face bend, followed by the bending, and finally sucessfully passing the face bend test.

The Bend Test Results

Here is the final results, both coupons passed the bend test, so there is no need to use the alternate. The coupons were inspected and accepted. Finally 3G certified, and next I am taking the AWS D1.1 4G SMAW certification to finish the combo welding certification.