Cold Weather Makes Paint Thin, Why?

I purchased a gallon of John Deere primer last summer. When I opened it, it was nice and thick . My plan was to brush on the primer and let it fill the pits in the sheet metal. Brush, sand, brush, sand.... till I got the effect I wanted. Unfortunately, things didn't turn out the way I wanted, and the project got put on hold . When I opened the can this summer, I found the paint had thinned to almost water like consistency . Even after stirring it didn't get much thicker . What does the freezing weather due to paint that makes it thin so much? Is there any way to get to thicken up again other then leave the led off for an extended period of time? Thanks in advance.

I am not sure about the paint, but if you want to fill pits, you can use a polyester putty. It is like body filler except that it is easier to work with and it sands real nice and easy. It saves work and looks good when sanded and painted.

The putty is actually called "glazing putty" (usually packaged in a tube that looks like a fat toothpaste tube). It is talc suspended in a polyester vehicle, but does not do well on really deep defects. For those you do want to use a 2 part body filler. In either case, spreading it on in a thin layer so that it is almost completely dry in 2minutes makes it very easy to sand quickly.

An alternative to the glazing compound is to shoot a few layers of a "high solids" primer after the deepest defects have been filled withthe two part putty.

Regarding the initial post, if the paint layer itself gets too thick, it will be brittle and break- even on it's own if thick enough.

The stiffnes of the paint you saw initially was probably due to the air that was entrained into the paint when it was mixed originally. Putting it in a paint shaker will revive that thickness in most cases, but it will not have an affect on the finish itself. If anything, the film build will be thinner.

Spraying paint gives the best results, a brushed application will always leave some marks.

The putty I was talking about comes in a can and is made by Evercoat. It is called Polyester Putty. It comes in a blue can, and not a tube. I know about the glazing putty that you are talking about and it is NOT what I was talking about.

This is what I was talking about. Does it look like it comes in a tube? So we are talking about TWO DIFFERENT things here.

Actually we are describing the same basic product of talc and a polyester based vehicle/binder.

I have used PPG products, 3M products, and a few others, they all came in oversized toothpaste tubes, which makes them usually less expensive if you are only working on one or two vehicles.

They are designed to be aplied as an incredibly thin layer, which in some areas of a typical application they are thinner than a coat of paint such that you pretty much remove all that does not fill into surface irregularities.

No need to get testy over different packaging of largely the same item.

There are two part putties that feather thin, but they have such a short work window that they are really suitable for larger imperfections but do not fully cure in the bonding region when applied over a painted surface, unlike glazing compounds like "Red Cap", which work fine over a painted surface such as primed fender, but does not fill deep imperfection very well.

Also when working with a large panel such as a hood, the short work times of 2 part fillers just prevent them from being as useful as they could be. They do tend to be more flexible than the glazing putties, which is a benefit for larger surface defects, but their drawback is that they really need bare metal to adhere to in order to adhere the best they can.

No matter which material is used, it is unquestionably far better to use filler products made for the degree of defects encountered than to try and fill with multiple coats of paint. Many of those lacquer finishes that cracked in the heyday of lacquer cracked either due to adhesion problems of the filler, or the paint film layer got too thick and wound up too brittle.

Good answer John. I thought you were making a good point that was taken the wrong way. Thanks for the information. It was very informative.