Category Archives: How Come I Have Lots of Pinholes In My Welding?

How Come I Have Lots of Pinholes In My Welding?

If you have ever asked yourself  “How Come I Have Lots of Pinholes In My Welding?” Don’t worry, there’s lot of welders who experienced this. No worries, there’s a lot of solutions that you can do to prevent or lessen them. Pinholes are sometimes called as “metal porosity”. It is a weld defect that is fairly common but as I said, there’s no need to worry since it is also easy to get rid of them as well. When we say weld porosity or pinholes we are referring to the little holes that you can see on the surface of your weld. If you see a porosity in your weld, keep calm since it isn’t considered as a serious defect. Keep in mind though that there are what we call the weld code or standard, and your finished product having pinholes or porosity may not be considered as a good finished product.


If you constantly have porosity in your finished welds, then you may have to change somethings about your welding style because it is usually a  because of something you overlooked or aren’t doing properly. Here are some reasons for porosity:


  • You should check out your welding material for the presence of moisture which can lead to problems. It can be as simple as running water or morning dew which can condensate from welding on heavy plates and lap joints. This can occur below 50 degrees F.  The solution for this is to simple preheat the metal to 200 to 220 degres F to get rid of the moisture.
  • You should also check if the weld nozzle is too far away from the weld puddle. You see if that’s the case, the volume of the shielding gas has been diminished and the dilution of the shielding gas with the atmosphere will really affect the weld. The solution for this is to make sure that the nozzle isn’t too far away or even too near.
  • Check your cylinder out! It might just be out of gas! Time to buy another one!
  • Don’t forget that air or a draft can disturb the delivery of the shielding gas during the welding process. If you think 25 feet away is already safe, then think again. Welders will also have to be careful when opening doors and of the air that is being discharged from the machinery he or she issuing.
  • The presence of paint, grease, oil, glue, and sweat can also affect your weld product. You see these compounds release large volume of gasses when they are exposed to arc welding. You can bet that this is especially true with solid-wire GMAW and gas tungsten arc welding, but keep in mind that FCAW arc processes can be vulnerable as well. The flux make up was not designed to hand such contamination so don’t forget about that.
  • Just like the pain and other compounds we have talked about above, mill scale and rush when welded over form decomposition gases and oxidation process can begin because of it. There is a strong possibility of cold lapping and lack of fusion at the welds can also exist. When the metal oxidizes, it is no longer truly a metal and you can’t expect it to return to the same metal, most especially if the welding flux has not been fixed.


What other reasons do you know that can cause porosity? There are also some epoxy available in the market or online markets that you can use to cover up the holes if they are bothering you or can’t really be removed.


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