# How to calculate welding time

• posted

Hi,

Hope you can help, I want to calculate the MIG welding time on a manufacturing project using box sections and tube. Can anybody give me any pointers to calculating a good estimated welding time??

Regards

Alec

• posted

If you know the weld geometry then, calculate the weld cavity volume. & by knowing the density of depositing material with 80 to 90 % dilution of depositing material in weld bead, find out the mass required of consumable electrode. As your welding is MIG, we know that, the deposition rate will be 6 to 8 kg/hr., so divide the mass required with deposition rate you will get the theoretical welding time.

• posted

Weld cycle times are the sum of the actual weld time plus the positioning time plus the fixture load time. Any or all can be significant depending on your project.

Weld time on thick sections is limited by the the deposit rate of the wire feed. Thin sections are limited by fitup issues, triggering, and the need to dial down the welder to avoid burnthrough. Mid range (eg

1/8" to 3/8") with good fitup is limited by how fast you can move the weld pool, somewhere around 20 to 30 inches per minute.

Positioning time is simply how fast can you move from one weld to the next. On a robot, this is typically around 1 second. A person needs to move, steady, brace, flip the helmet, and fire. Don't forget to either reposition the weldment or deal with out of position welds. On a large tubing structure weldment, the arc time can be way below 20%.

I used to model the weld times for potential robot weld centers. Expected the actual to match theoretical within 3% or so. But that required every joint to be analyzed.

With as much data as you have given, try 20 inches per minute for all the weld, multiply by 3 to 5 for positioning time. Can't do any better without a set of prints to look at. Of course for a modest fee............

alecgreen wrote:

• posted

"RoyJ" wrote: (clip) With as much data as you have given, try 20 inches per minute for all the weld, multiply by 3 to 5 for positioning time. (clip) ^^^^^^^^^^^^^^^ This reminds me of how we used to weight cows down on the farm. You look for a long straight pole, and balance it on a rail fence. You tie the cow to one end of the pole, and then look for a big rock that will just balance the cow when tied to the other end of the pole. You then estimate the weight of the rock. ;-)

• posted

I know Lincoln and Miller have applicable literature. The one thing I have found useful is to compare the actual time to weld an assembly and the theoretical time to do the length of welds. In the type of work I do which is structural most every piece is different than the next. The operating factor often works out to a ratio of five to one. A welding time estimated as ten minutes ends up taking fifty minutes when turning and handling and spatter removal is taken into account. The most important item learned is that welding time is really not as important as welding salesman tell you. More time can be saved by good planning and effective crane equipment and procedures. They will try to sell you a wire or gas that will increase production. Even if the new wire or gas increase welding speed by double you only save five minutes out of the fifty it took you to weld the assembly. Straight production of hundreds of identical pieces is another matter of course. Suit and Ties often make an ignorant comment about how much faster one welder can weld than the other employees. It isn't the welding that is faster when everyone has the same machine. What is different is that person is planning his number of turns and his whole work area to reduce repetitive handling. Just my thoughts on welding speed/time. Randy

Hope you can help, I want to calculate the MIG welding time on a manufacturing project using box sections and tube. Can anybody give me any pointers to calculating a good estimated welding time??

Regards

Alec

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