Troubleshooting Conversion Varnish Off-Gassing Odor

Formaldehyde or catalyst odor can draw customer complaints. July 26, 2010

Has anyone experienced extreme odor inside of finished cabinets after using Mohawk conversion Varnish Low 275 VOC? I may be asked to remove cabinets from a house, which I didn't get paid for yet. Any suggestions on this issue?

Forum Responses
(Finishing Forum)
From contributor D:
Just the way it is. As conversion varnish reacts it emits formaldehyde (which is why it's barred in parts of Europe as they really have a problem with formaldehyde and is why they use so much 2K urethane). After time it goes away but in an enclosure it can linger for months. Only baking can speed this process up. When I use conversion varnish inside of anything I let the part sit outside in the sun for a day (and I live in Phoenix which gets hot) to bake and off-gas. I do this with drawer boxes.

From contributor T:
Generally, the odor people complain about is either formaldehyde or excess catalyst (acid) from a product that has been over catalyzed. Formaldehyde is very obvious and has a very distinct formaldehyde odor. Excess catalyst also has a distinct rotten eggs smell (for lack of a better term). When the sealer coat has been over catalyzed (and topcoated with the correct amount of catalyst) the rotten egg smell can be hidden for up to a month or so. However, free catalyst or over catalyzed sealer will eventually migrate to the top and create an obnoxious order. If the topcoat has been over catalyzed you will have the rotten egg smell after a couple of days. The problem can be worse depending on the resin system used in the conversion varnish. CAB resins seem to be the worst.

From contributor S:
Did you use any universal tint colors in the CV? The vehicle in the colors can react with the CV and it can stink for months if not longer.

From contributor C:
I know that shellac can be use to seal in smells. I'm not sure if it will work over other finishes but I know it can be used to seal the inside of cabinets exposed to mothballs and the like.

From contributor F:
Get some box fans and run them on the offending pieces for a few days. Moving the air is your most friendly technique right now.