Temperature-Related Problems with Conversion Varnish
Cross-linking finishes can suffer haze, flecking and other appearance problems if sprayed in an environment that lacks good temperature control. March 25, 2007
Question
I used S-W water white conversion varnish on a cabinet order and everything seemed to go fine, just like the previous hundred or more sprays. But the next day, the drawer boxes and cabinet doors had very tiny white spots on the flat portions, and some of the grain (it's oak) had white haze in it. I assumed some dust or contamination to be the problem, resanded, wiped off any dust, re-stained some of the deep grain (drawer fronts) and resprayed. When wet, it looked fine. Unfortunately, the next day more white specks on the boxes and haze in the grain. Temperatures in my shop can vary, but I try to keep 60's during the day but often get 50's at night. I raised the temps and did some test spray and everything came out fine on the samples. How do I get rid of the spots that are on the drawer bodies, and is there any way to clean the haze out of the grain?
Forum Responses
(Finishing Forum)
From contributor A:
Sometimes if you apply CV and it's too cold, you can get odd looking stuff happening, like textures and hazes. Often, this goes away when it warms up and catalyzes. Sometimes you have to sand it off and start over.
From contributor R:
It's been several years since I used this product, but I learned the hard way you don't spray this stuff when it is cold - under 70 degrees, if I remember correctly. Had to strip several mahogany tops down to bare wood and start over. At the time the data sheet did not mention this limitation, but I found out when I contacted them regarding the problem… very nice.
From contributor I:
I've had a little trouble with older stock that I did not filter well enough before going to the gun. The stearates used to reduce the gloss will clump a little when the material gets older. Can't help with the haze part.
From contributor U:
Contributor R is correct. While CV is a great product, it is a little more critical in that the temperature must be consistent throughout application as well as curing process. It's a cross-linking product and if conditions are not where they should be, problems can occur. If you're spraying in an uncontrolled environment, you will have issues often.
