Tyvek or Laminated “Chemical Coveralls” as VBL???

David, I guess you know that vapor barriers don't do that much good except in extremely cold environments (probably well below 0 F). Do you see much of that in Southern California?

–B.G.–

I know what you are talking about but never taken a good look at one in real life.
The possible problem I see is that they are made to be worn over some clothing so largish and some of the seams or zipper may rub against the skin inside the sleeping bag.
As far as I know they are more or less disposable so by definition non long-lasting.

They sell those everlast sweat suits boxers use to loose weight

Should be fairly cheap

;)

The Tyvek Coveralls are surprisingly durable and make a great, cheap storm worthy rain suit. You just have to tape the seams and then cut the coat to length and then make chaps out of the pants. Will Reitvald has a blog post with directions.

They do breath somewhat so they wouldn't function like a true vapour barrier but more like putting on a Non-Event level 2 layer WPB. So they definately add warmth.

Ditto to what Greg F posted. I did something similar to what Will did. Search my posts if interested. I have worn my Tyvek jacket to sleep in and it does add some warmth. It doesn't work as a VBL though.

Re the other poster stating that VBLs don't work except in very cold conditions; I beg to differ. I've used some sort of VBL for …perhaps 15 yrs. I don't winter camp…and I don't use any sort of VBL in the height of summer. I get great results beginning some where under 40° though. Others have reported similar findings.

I've been using a 72" long plastic garment bag from the dry cleaners for the last couple yrs. Cost me .25 cents and weighs 1.56 oz.

"David, I guess you know that vapor barriers don't do that much good except in extremely cold environments (probably well below 0 F). Do you see much of that in Southern California?"

I completely disagree with this. I have very successful used VBL at temperatures slightly above freezing with reduced layering. While normally it is used for lower temperatures I have found that I can stretch my normal three season gear into four season with just the addition of a VBL. If I had a summer bag I would experiment with pushing the limits of that bag down below freezing. I have been amazed at how effective it has been at keeping my feet warm.

For those responding that the Tyvek suits would not work as a VBL, are you considering/including the "Tychem" suits which are coated with polyethylene? These are different than the standard Tyvek coveralls which have been adopted for rainwear, etc.

"I completely disagree with this. I have very successful used VBL at temperatures slightly above freezing with reduced layering. While normally it is used for lower temperatures I have found that I can stretch my normal three season gear into four season with just the addition of a VBL."

+1. I use a VBL a lot (a cuben shirt when RBH was making them) when it gets below 40 degrees, and find that I can use a lighter quilt/less clothing when I do. I'm a big fan of VBLs well above 0.