Vapor Barrier Mount Technique
 

I have done this for so many years with good results so I thought I would share with the forum my VB replacement technique. I buy the heaviest mil clear plastic (opaque really) that I can find. I then mount a series of velcro 1 inch strips on door following the original glue line. I mount the velcro so that both sides are adhered and I peel off the paper strip to expose the adhesive on the VB side. I have a large rectangle of plastic sheeting pre cut ( 3'x4' roughly) and press against velcro adhesive starting at the top horizontal side and then move top to bottom, side to side creating tension so there are no wrinkles. I then take an exacto knife and follow the contours of door panel cutting away excess plastic and then cut out the various areas for door panel mount clips (make an x with exacto knife) door handle mounts, etc. and voila done and not prone to tearing for future R&R work. Why Velcro? In the future, when you need to go back into the door, you can carefully detach velcro without destroying VB so that you can lubricate regulators and perform other repairs easily. Re-attach velcro and VB is resealed. Makes maint. much easier and will last longer than original VB material. Good luck!

... doesn't the velcro allow air movement? I thought the point of the VB was sealing movement of air?

MB originally used glue to stick the VB to the door, I use that too along with 3.5 mil plastic sheeting from Home Depot. Its a good technique for cars with straight door cards like the W123 and W124, If you have a car that has sunk door cards you need a fully water tight seal on the VB.

I helped a friend on his BMW 530i 2002 to fix water leaks - used 3M window weld ribbon and a heat gun to stick the foam VB in place. We also fixed a Honda accord with a HD contractor trash bag as vapor barrier and the same ribbon sealer then cut with an exacto knife along the periphery of the new VB. Looked nice - and that trash bag is THICK

I've done basically the same thing except I use Elmer's spray glue to attach the VB's. It peels off easily if you need to remove it then just spray it again to reattach.

Last I checked, vb's were five bucks from the dealer. Any idea if they are still available?

Is five bucks too much for oem plastic bag material? :D

It is when you've got a roll of visqueen sitting on a shelf;)

I usually just duct tape the old one back on....

... 5 DOLLARS? for .0001mil plastic? the double roll of 6mill contractor bags is like 15.00... and it comes with enough to cover every member's door...

The door panel has a way of pressing and containing the VB - I just like the convenience of the heavier material and the ability to open quickly without tearing anything for maint. etc. I have done this for years and have never experienced swelling of door panels, excessive moisture, etc. True, door moisture could migrate through any gaps between velcro mounts but again, I think the door panel has a way of sealing the VB as well through light pressure. I think if window moldings, glass channels were badly worn, torn or non existent there could be a problem - I have owned more than a few cars that apparently had not had a functioning VB in years until I pulled the panel to discover there was no VB with no apparent damage to the panel - I orginally began this years ago with a BMW 2800 cs coupe with the usual window motor issues -

Newer cars use this semi-reusable caulk instead of spray-on glue.

http://www.amazon.com/3M-08578-Black-Strip-Calk/dp/B000PEZ1L4

I use double sided carpet tape.

I've just used the purple glue stick sold at Staples etc for kids gluing. It works great and is sticky afterwards for repositioning. Used on bugs, repositioning the Mercedes panels and when fixing the Honda. Worked fine.

the oldest of the japanese cars (1960's) used this too.

Them contractor trash bags are wonderful for this application, if you are looking for some "fun" use the hazmat one.