We have had a couple of jobs turn fire engine red on oak and cherry. It seems as if it is product related. Has anybody had this problem with conversion varnish? We have tried to recreate the situation with contaminants but no luck.
From contributor A:
I have seen this with iron contamination of the acid cured coating. The most likely source is the can, bucket or plumbing and pick-up tubes on the spray equipment. The acid leaches the iron from any mild steel components in the system and applies the iron to the surface along with the coating. Over time the iron rusts within the cured coating. Usually this occurs when the components have been in use and broken down considerably or where the acid is very strong or the catalyzed material is stored for long periods in contact with the mild steel.
Prevention is achieved using stainless steel components approved for exposure to acid as well as resistant plastics in all wetted applications. No empty mild steel buckets, pails or cans should be used to store, measure or dispense acid catalyzed materials once activated. Even those pails with a thin phenolic paint liner are not acceptable once the coating is catalyzed. Also, avoid aluminum as it pits and dissolves in some acids. This condition is not dependant on wood species. The solution to your problem on the installed product is to redo. It is not a reversible situation.