Spot Welding

Questions and Answers

Other articles in this blog describe:

WHAT IS UPSLOPE IN RESISTANCE WELDING?

IS UPSLOPE HELPFUL IN REDUCING SPATTER OR EXPULSION IN RESISTANCE WELDING?

To summarize here what these articles contain, upslope is used to slowly heat up the part as the heat initiates before full current application. This give the parts a chance to realign, relax/anneal, adjust position, melt coatings and contaminants and improve the part to part contact before full current is initiated. The end goal is for better contact and less expulsion.

 TIME DIAGRAM ILLUSTRATES COMPLETE FUNCTIONS

Upslope is shown in the first section of the red current line - as it increases. This period is often used on galvanized materials to allow the zinc to melt and be pushed out of the joint. In other cases it is a chance for the components to anneal or relax and get all material into full contact before full power is applied.

Reference: RWMA – Resistance Welding Manual 4th Edition

That is an interesting question. Stainless is highly resistive and won’t conduct heat too far or fast but the plastic is only 3 mm away.

My gut says without some sort of extra cooling the plastic is likely to see some heat.  I trial run is needed.

Is water an issue? Put a mist of water in the weld area as the part welds, similar to a seam welder just less water. Initiate the mister with the weld cycle.

Make sure the electrodes are cooled well to reduce time at heat. Minimized the size of the weld and weld nugget. Keep the electrodes in place after the weld to pull heat out.

GOOD LUCK!

For each new resistance welding job there will be a known weld schedule or one must develop a weld schedule. For simplicity we will assume there is a known weld schedule. The data generally supplied is the electrodes and related tooling to use. The data may look like the chart below:

 16 Gage Low Carbon Steel Weld Schedule C1.1

After researching this product on the web, I found that Weld Aid is a chemical product sold in several forms. Mostly liquid for precleaning industrial metal products. Some cases it is used to coat tooling and fixtures to reduce weld splatter from adhering. There is also a version to preclean wire fed into Mig welders.
As to using this product in a resistance weld joint? You can try it of course.

I see not benefit and it would not be high on my list of experiments.

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