We need recommendations for cleaning stainless steel weldments. A Walter weld cleaning machine is being used. Currently we have tried using Luminox but sometimes it does not produce satisfactory results.
Luminox is a very light duty cleaner used to remove light oils and tiny particulates from delicate substrates. Generally, stainless steel is not considered a delicate substrate. In this case the recommendation would be 2% Citrajet at 60 deg C for 10 minutes followed by a water rinse. Citrajet is a mild organic acid cleaner (pH 2.5) that is good at removing heat scale and discoloration around weld joints as well as being a good general purpose cleaner. The cleaning results with Citrajet will be much better than luminox.
Note, if for some reason you need to use Luminox and are satisfied with the light duty cleaning it gives, I would recommend using it at a 3% concentration at 60 deg C for 10 minutes but I would not expect it to clean as well as Citrajet.
Citrajet is low foaming like Luminox and probably a low foamer is preferable to use in junction in a large dip tank. If you for some reason have a particularly oily substrates to clean, we do make a high foaming cleaner called Citranox (manuf cat no 1801 for the 1 gal size) that would give the same heat scale and discoloration cleaning while doing a better job on oily residues. I am guessing you do not have particularly oily substrates to clean and that you will be happier with the low foaming version.
Citrajet (manuf cat no 2001 for a 1 gallon size) should be available from whatever dealer you get your Luminox from such as VWR, Thomas, Cole-Parmer or other lab and health supply dealers.