1. My welding machine keeps shutting off after I've been welding for 5 to 10 minutes.
2. How many balloons can I fill with my Helium tank?
3. What do the numbers on welding rod mean?
4. Cable size verses cable length?
5. What do the terms TIG and MIG stand for?
6. What size cutting tip do I need?
7. What tip sizes do I use for oxy-acetylene welding and what pressures do I set on my regulators?
8. What is the difference between brazing and welding?
9. What is Duty Cycle?
10. What shielding gas should I use?

1. My welding machine keeps shutting off after I've been welding for 5 to 10 minutes.

You are probably experiencing the effects of Duty Cycle. Many machines are designed to shut down automatically after a period of continuous operation. This feature is there to protect the machine from over-heating. Click here for a more detailed explanation of duty cycle.

2. How many balloons can I fill with my helium tank?

It depends on a couple of things, the size of the balloons and the tank size. Temperature and tank pressures are also factors. The chart below will give you an approximate number of balloons based on these factors. The chart assumes that the tank is full and that you're not over-inflating the balloons.

Note: You won't get 125 balloons if the tank is half full and the 9'' balloons you've bought are inflated to twice that size.

Helium Cylinder Size	Tank Pressure	9''	11''	14''	16''
50 cu.ft.	2200 psi	125	60	35	25
60 cu.ft.	2200 psi	175	100	50	40
90 cu.ft.	2200 psi	250	120	70	50
125 cu.ft.	2200 psi	340	180	90	75
251 cu.ft.	2200 psi	680	360	180	150
336 cu.ft.	2650 psi	940	500	250	200

3. What do the numbers on welding rod mean?

Arc welding electrodes are coded by the American Welding Society [AWS]. Each AWS number gives complete information about the electrode.

Classifications of mild and low alloy steel electrodes are based on an 'E' prefix and a four or five digit number.

• The first two digits [or three, in a five digit number] indicate the minimum required tensile strength in thousands of pounds per square inch [psi].
  
• The next to last digit indicates the welding position in which the electrode is capable of making satisfactory welds. [1 = All positions, 2 = Flat position and horizontal fillets].
  
• The last digit indicates the type of current to be used and the type of covering on the electrode [see fig. 1].
  

Fig 1.

FOURTH DIGIT	TYPE COATING	CURRENT
0 1 2 3 4 5 6 7 8	ORGANIC ORGANIC RUTILE RUTILE RUTILE, IRON POWDER LOW HYDROGEN LOW HYDROGEN MINERAL IRON POWDER LOW HYDROGEN, IRON POWDER	DC+ only AC, DC+, DC- AC or DC- AC, DC-, DC+ AC, DC-, DC+ DC+ only AC or DC+ AC, DC-, DC+ AC or DC+

Example: E6010

a.	The prefix [EXXXX] designates an arc-welding electrode.
b.	The first two digits [E60XX] indicate a minimum tensile strength of 60,000 psi.
c.	The next digit [EXX1X] indicates position; All positions.
d.	The last digit [EXXX0] indicates an organic coating and DC+ current

4. Cable size vs. cable length

POWER CABLE

Wire Size	Max Amp @ 100 ft.	Voltage Drop / 100 ft.
4	105	2.6
6	80	3.2
8	55	3.42
10	40	4.0
12	25	4.0
14	20	6.4

Welding Cable

Amps	Duty Cycle	Cable Sizes Required per Lengths
		0 - 50 ft.	100 ft.	150 ft.	200 ft.	250 ft.
100 150 180 180 200	20 40 20 30 50	8 6 5 4 3	4 5 4 4 3	3 3 3 3 2	2 2 2 2 1	1 1 1 1 1/0
200 200 225 225 250	50 100 20 40 & 30 30	2 2 4 or 5 3 3	2 2 3 3 3	2 2 2 2 2	1 1 1 1 1	1/0 1/0 1/0 1/0 1/0
250 250 300	40 100 60	2 1 1	2 1 1	1 1 1	1 1 1/0	1/0 1/0 2/0
325 350 400 400 500 600 600 600 650 650	100 60 60 100 60 60 80 100 60 80	2/0 1/0 2/0 3/0 2/0 3/0 2 -1/0 2-1/0 3/0 2-1/0	2/0 1/0 2/0 3/0 2/0 3/0 2 -1/0 2-1/0 3/0 2-1/0	2/0 2/0 2/0 3/0 3/0 3/0 2 -1/0 2-1/0 4/0 2-1/0	2/0 2/0 3/0 3/0 3/0 4/0 2-2/0 2-2/0 2-2/0 2-2/0	3/0 3/0 4/0 4/0 4/0 2-3/0 2-3/0 2-3/0 2/3/0 2-3/0
800 800 1000	80 100 80	3-1/0 2-3/0 2-4/0	3-1/0 2-3/0 2-4/0	3-1/0 2-3/0 2-4/0	2-3/0 2-3/0 2-4/0	2-4/0 2-4/0 4-2/0
1000 1200 1200 1500 1500	100 80 100 80 100	3-3/0 3-4/0 4-4/0 4-4/0 5-4/0	3-3/0 3-4/0 4-4/0 4-4/0 5-4/0	3-3/0 3-4/0 4-4/0 4-4/0 5-4/0	3-3/0 3-4/0 4-4/0 4-4/0 5-4/0	3-3/0 3-4/0 4-4/0 4-4/0 5-4/0

5. What do the terms TIG and MIG stand for?

TIG [Tungsten Inert Gas] and MIG [Metal Inert Gas] refer to two electric welding processes in common use today. They are very different and each has characteristics making them suitable for particular welding applications. In brief; TIG welding uses a non-consumable electrode that provides the arc and a separate filler material in the form of a rod. In addition, the TIG torch delivers a shielding gas to the weld site to minimize weld oxidation and/or alter the characteristics of the weld metal. In technique it is much like handling an oxy-acetylene torch though it is an electric process rather than flammable gas. It produces high quality welds and is especially suitable for aluminum and stainless steel metals.

MIG welding uses a device to automatically feed welding filler material into the weld site. The material is in the form of wire and the wire itself is the electrode. As it is with the TIG torch, the MIG torch delivers shielding gas to the weld site although welding wire is available that produces its own shielding gas in much the same way flux coated stick electrodes do.

The American Welding Society refers to these two processes as GTAW [gas tungsten arc welding] for TIG and GMAW [gas metal arc welding] for MIG.

6. What size cutting-tip do I need?

The type of torch you are using and the thickness of material being cut determine the proper size cutting-tip for use in oxy-acetylene flame cutting.

Reproduced below are the cutting tip charts for two of the most popular types of torches in use. Call or email us if you don't see your particular torch listed here.

Harris Cutting Torches & Tips

Thickness of Metal in Inches	Tip Size	Oxygen Pressure [PSIG]
Light gauge to 3/16 3/16 - 3/8 3/8 - 5/8 5/8 - 1 1 - 2 2 - 3 3 – 6	000 00 0 1 2 3 4	15 - 30 20 - 30 30 - 40 35 - 50 40 - 55 45 - 60 50 - 75
For acetylene, use one piece tips with 5-6 PSIG acetylene pressure. For MAPP, natural gas, or propane, use two-piece tips with 4 oz/sq.in. or higher fuel gas pressure

Victor Cutting Torches - Tip Series 1-101, 3-101, 5-101

Metal Thickness	Tip Size	Cutting Oxygen [PSIG]	Preheat Oxygen [PSIG]	Acetylene [PSIG]
1/8' 1/4' 3/8' 1/2' 3/4' 1' 2' 3'	000 00 0 0 1 2 3 4	20/25 20/25 25/30 30/35 35/35 35/40 40/45 40/50 45/55	3/5 3/5 3/5 3/6 4/7 4/8 5/10 5/10 6/12	3/5 3/5 3/5 3/5 3/5 3/6 4/8 5/11 6/16
-CAUTION - At no time should the withdrawal rate of an individual acetylene cylinder exceed one-seventh of the cylinder contents. If additional flow capacity is required, use an acetylene manifold of sufficient size to supply the necessary volume.

7. What tip sizes do I use for oxy-acetylene welding and what pressures do I set on my regulators?

Tip sizes and gas regulator settings are dependent on the thickness of the material to be welded and the type torch being used.

Reproduced below are the tip charts for two of the most popular types of torches in use. Call or email us if you don't see your particular torch listed here.

Harris Welding Torches & Tips

Metal Thickness	Tip Size	Rod Size	Oxygen [PSIG] E. P. U. P.		Acetylene [PSIG] E. P. U. P.
3/64' 1/16' 3/32' 1/8' 3/16' 1/4 - 3/4'	1 3 5 5 7 9	1/16' 1/16' 3/32' 1/8' 5/32' 3/16 - 3/4'	1 3 5 5 7 9	15 20 25 25 30 35	1 3 5 5 7 9	.25 [4 oz.] or more
E. P. = Equal Pressure U. P. = Universal Pressure

VICTOR Welding Torches & Tips

Metal Thickness	Tip Size	Oxygen [PSIG] Min. Max.		Acetylene [PSIG] Min. Max.
Up to 1/32' 1/16 - 3/64' 1/32 - 5/64' 3/32 - 7/64' 1/16 - 1/8' 1/8 - 3/16' 3/16 - 1/4' 1/4 - 1/2' 1/2 - 3/4 3/4 - 1'	000 00 0 1 2 3 4 5 6 7	3 3 3 3 3 4 5 6 7 8	5 5 5 5 5 7 10 12 14 16	3 3 3 3 3 3 4 5 6 8	5 5 5 5 5 6 7 8 9 10

8. What is the difference between brazing and welding?

Brazing is a process wherein metal is joined together by heating the base metal to approximately 800°F and then using a non-ferrous filler metal having a melting point below that of the base metal. The filler metal melts and adheres to the base metal. The base metal does not melt and there is no fusion as in welding processes.

Most commercial metals can be brazed. Although brazed joints have a relatively high tensile strength they do not possess the full strength properties of conventional welding techniques. One very useful characteristic of brazing is its ability to join dissimilar metals.

9. What is Duty Cycle?

Duty cycle is the amount of time in a ten-minute period that a welding machine may be operated continuously without fear of overheating or damaging its components. Duty cycle is expressed as a percentage [%].

For example, a machine with a 60% duty cycle at 200 amps may be operated continuously for 6 minutes at that amperage [60% of 10 minutes]. The remaining four minutes of the cycle should be used to cool the machine down.

Duty cycle percentages will change for a given machine depending on the output selected. It is possible to have several duty cycles listed. In general, the higher the output the, lower the percentage or time allowed.

You should also note that many welders manufactured today are equipped with devices that will automatically shut the machine down if operating temperatures are exceeded. Letting the machine cool down will normally reset the system.

10. What shielding gas should I use?

The primary purpose of shielding gas is to displace the air in the weld zone and thus prevent contamination of the weld by oxygen, nitrogen, or water vapor. No single shielding gas can be used with every welding process or every metal.

Argon [A], helium [He], and carbon dioxide [CO2] are the principal shielding gases used. Oxygen [O2] is used as an additive to stabilize the welding arc. Listed below are some of the more common gas and gas mixture applications.

BASE METAL	SPRAY TRANSFER	DIP TRANSFER	PULSED SPRAY
Stainless Steel	A + .5% O2 A + 1% O2 A + 2% O2	90% HE + 7.5% A + 2.5% CO2	A + .5% O2 A + 1% O2 A + 2% O2
Carbon and Low Alloy Steel	A + 1% O2 A + 2% O2 A + 5% O2 A + 5% CO2 A + 8% CO2	CO2A + 25% CO2 A + 8% CO2 A + 5% CO2	A + 1% O2 A + 2% O2 A + 5% O2 A + 5% CO2 A + 8% CO2
Aluminum and Magnesium	Argon Helium A + 25% HE A + 75% HE A + .15% O2	N/A	Argon A + 25% HE A + 75% HE A + .15% O2

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