Propane - does it work?
Ron in Drums PA
>When I first heard about using propane to prevent finishes from curing it sparked my interest. I�m not trying to set myself up as an expert, but I just like to share my experiences.
Back in July 04, I was wiping on my favorite finish, varnish and mineral spirits, on a desk and bookcase I was finishing up when I read on this list about propane. I decided to experiment a little to see what happens.
I had four jars, in two of them I poured about an inch of finish. One I gave a squirt of propane, the other I did not. Next, I cut in half the rag I was using to wipe on the finish and inserted each half into its own jar. Once again in one I gave a squirt of propane in only one jar.
I made sure the lids where nice and tight and forgot about them for a month. I didn�t open the jars with just the finish, but I could see it was still liquid when I moved the jar. But when I opened up the jars with the rag and noticed that the one that did not have propane was very stiff while the other with the propane was just as moist as when I inserted the rag.
Late September 04, I took a look at the jars with the finish. I noticed immediately that the jar that did not have propane that the finish skinned over. While the jar with propane, the finish did not skin over.
Today (February 05) I checked on the jar and still no skin. I�d like to note that this jar has never been opened.
I think the key here is, if you are taking a can of finish, opening it up and using it every couple of days, you are introducing oxygen, which will come in contact with the finish causing it to polymerize over time, regardless if you are squirting propane after each use. You may slow down the process a little but you will not stop it.
But so far it seems, that over a longer period of time (seven months and counting) if the jar stays closed and is not used, using propane does seem to have a desirable effect of helping the finish not to skin over.
