as far as i know defects in castings are welded (at the foundry). if the porosity is "cosmetic" i would adhere to the recommendation for the coating that will be applied. dont use 200 years old recipies that might have worked for specific applications only.
Probably because of research the newer products are more successful. I would be more concerned with color matching.Not saying it is better or cheaper, just a puzzle to try to find a product that has been successful for many years.
That is an odd-looking casting defect. I am not sure what caused it. Usually visual inspection gives pretty good clues. Did the foundry guys say what their understanding was?Denis,
I never thought about West Systems, so I'll look into that.
I've had no problem with the foundry welding their voids as they make their own filler rod and I have to trust their experience and talents as to pre/post heat.
I don't know if that is the substance I'll try, but it will be covered in black paint, so color matching is not a concern on this project, but certainly something to consider.