TheSamba.com :: View topic - Vapor Barrier Replacement How-To

Tue May 03, 2016 10:00 am

I'm sure you mean well, but you forgot to check my location first...

asiab3 wrote: http://www.amazon.com/3M-Repositionable-Clear-Adhesive-10-25-Ounce/dp/B000BKQD82
"This item does not ship to Saskatoon, Canada."

https://www.amazon.ca/gp/offer-listing/B000BKQD82/ref=dp_olp_new?ie=UTF8&condition=new ... $ 57.78 + $ 26.14 shipping

Quote: https://www.zoro.com/3m-spray-adhesive-size-16-oz-...lsrc=aw.ds

American. Not sold by their Canadian outlet: https://www.zorocanada.com/s/?c=4&b=1%093M

Quote: Grainger also stocks it.

Grainger is American only. Their Canadian company is Acklands-Grainger. They don't carry it. https://www.acklandsgrainger.com/en/category/3M/Ad...wu8tZ1rou?

Tue May 03, 2016 10:15 am

Thank you for the correction. Those websites list specific locations they will not ship to, but all of them are states or islands in the US on my screen. I bet because the website sees my browsing location, that it only gives me info on shipping to my country.

I'd be glad to purchase and send it to you if you'd PayPal for the cost plus my shipping charges. If you can't find a cheaper source, let me know!

I'm not posting these for you to buy, because they probably have the same shipping reasons, but they are similar enough products that you might be able to source them locally or shipped to you.

http://www.amazon.com/Krylon-10-25-Ounce-Repositio...3GRDTZDV9G

http://www.amazon.com/ELMERS-Repositionable-Mounti...3GRDTZDV9G

Good luck!
Robbie

Tue May 03, 2016 10:23 am

asiab3 wrote: http://www.amazon.com/Krylon-10-25-Ounce-Repositio...3GRDTZDV9G

Good luck!
Robbie

Thanks anyway!! Krylon repositionable is the one I can get cheap from Amazon, only $12.87 and free shipping since I already had an order going in my cart. I just wanted long-term feedback from someone who's actually used it. Someone mentioned using it further up the thread, circa 2013, so that's enough winters and summers to know how it held up. busdaddy said he's got 12 years from the 3M #75 already, so I was hoping someone had similar longevity results from the Krylon. Krylon is generally a good brand, so I'm not sure if it's cheaper because of 3M's brand recognition, or because it's inferior. Not that it matters much at this point, it's the only thing I can find and I'm just going to use it anyway! I'd really like to be able to re-lube my door mechanisms every year, and the vapour barrier is the only (ahem) barrier to making that convenient and therefore likely to actually happen.

Does anyone have a recommendation for a spray to use on the back of the panels? I was thinking of rubberized spray, but I'm concerned it would add too much thickness and interfere with the clips. The guy at Home Depot recommended urethane, but he works at Home Depot so what does he know?

Tue May 03, 2016 9:00 pm

I know that I am in in the extreme minority crowd on this. But the route I took for several different reasons was to use the "Duck" double faced carpet tape. The results were absolutely perfect. I found out the hard way that there is only one adhesive made by 3m to successfully attach the flap. Everything else will fail in short order. I don't have the tube in front of me and the power is out but if anyone wants to know what to use to adhere the flaps I will gladly share. There really is no reason to remove the entire vapor barrier. This was an inexpensive way for Vw to do it. When I need access back into the areas that need to be lubed I will simply break out the exacto knife and cut a hole in the barrier. Then once the maintenance is done I will patch a piece in with the correct adhesive. The tape holds the barrier perfectly and it's tight as a drum. It probably takes a lot longer to do it this way but I am very happy with the results. As far as coating the panels I went with Rustoleum outdoor water based spray bomb....Varathane. Low VOC's no sanding between coats. I went further then most because I installed BD's door panels that are beautiful and better made then the originals. If anyone wants pics PM your email and you can post the pics. Hope this helps!

Sat May 14, 2016 6:53 pm

Finally got mine done today. Used the Krylon repositionable. Note to self: ignore the directions and apply liberally. A "light mist" is not enough, at least for 6mil poly. But it all worked out in the end. I used the most expensive gaskets and clips they had at CIP (used my original clips where they weren't broken). The gaskets were waxed already so I didn't feel the need to lube them. I used a 4mm ball-end allen key to shove them in, worked like a charm, no punctures, went in really easily. The clips were tight, but I suppose that's the point. I don't think the panels will be as easy to remove next time as they were this time, as those gaskets were 40 year old rubber and had no grip left whatsoever.

All told, it took about 3 full days to do both lock mechanisms and the vapor barrier / panels.

I kept thinking "I threw in the towel" along the way and giggle every time. It took me a couple reads to pick up on that, so when it clicked, I apparently found it hilarious.

Sat May 14, 2016 6:59 pm

Himejii wrote:
I kept thinking "I threw in the towel" along the way and giggle every time. It took me a couple reads to pick up on that, so when it clicked, I apparently found it hilarious.

It was a long six year wait for someone to finally get it. I thought it was hilarious too, back in my youth, way back in 2010.
Colin

Sun Nov 05, 2017 2:17 pm

I'm about to cut out some vapor barriers, but I'm having trouble understanding what the flap looks like. How is the flap different than just a single sheet covering the entire door? I see where the top attaches, but where does is the bottom supposed to go?

Thanks!

Sun Nov 05, 2017 2:43 pm

The flap goes inside the door, so that water that gets inside runs to the bottom where it drains out instead of getting between the plastic and the metal.

Amskeptic wrote:

Sun Nov 05, 2017 2:44 pm

surfbus23 wrote: I'm about to cut out some vapor barriers, but I'm having trouble understanding what the flap looks like. How is the flap different than just a single sheet covering the entire door? I see where the top attaches, but where does is the bottom supposed to go?

Thanks!

The flap gets tucked into the door at the bottom of the "hole" for the window. It doesn't get glued or fastened, just rests inside the door to divert excess water to the drain holes rather than have it sitting between the door and vapor barrier where it can leak and damage your door card and interior.

This is the best pic I have, hope it helps. The red arrows show the flap, and you can see where it tucks in. The rest of the barrier gets glued on the door around the holes for the door card fasteners.

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Sun Nov 05, 2017 2:54 pm

Ok. I think I got it now. How far down does the flap extend?

Edit: I guess what I'm asking is there is the narrow end of the door that has another opening and does the flap need to cover the backside of that opening as well?

Sun Nov 05, 2017 3:13 pm

Amskeptic wrote:

Like this

Sun Nov 05, 2017 3:30 pm

surfbus23 wrote: Ok. I think I got it now. How far down does the flap extend?

Edit: I guess what I'm asking is there is the narrow end of the door that has another opening and does the flap need to cover the backside of that opening as well?

The originals on my buses never covered that little opening at the front, but doesn't mean you could make a little flap for it.

Edit: I don't know if my original vapor barriers where ever tampered with by POs

Sun Nov 05, 2017 9:58 pm

Ok. Thanks all for the help. Final question. Does this get attached to anything or just float free? I got varying impressions. I know Colin used a clip on his, but if you clip it down wouldn't that affect airflow when the vent is open?

Mon Nov 06, 2017 7:54 pm

surfbus23 wrote: Ok. Thanks all for the help. Final question. Does this get attached to anything or just float free? I got varying impressions. I know Colin used a clip on his, but if you clip it down wouldn't that affect airflow when the vent is open?

The flap? Mine just get tucked in to the pocket. The rest of the barrier gets glued to the door, around where the door card fasteners are.

Mon Nov 06, 2017 11:24 pm

When I did my door I use some 3m acrylic double sided tape.

Something like this:

https://www.amazon.com/Tape-4910-width-length-Roll...&psc=1

Its comes in different sizes and I recommend the thinnest one that's about 1/4" wide. Its repositionable so long as its clean but can be cleaned with soap and water and after drying out will stick again.

Wed Apr 04, 2018 8:39 am

Will be taking on this job soon. Just snooping for updates on how some of these ideas mentioned are holding up.

Ray, what about EVA shower curtain liners (I realize “V” in there). What about Thermoplastic sheets? I can procure those products cheap in reasonable quantities. Where is a good place to get polyethylene film for this project? The carpet liner/protector idea is intriguing. But I’ll go with whatever just works.

raygreenwood wrote:
Also....and this goes back to a couple of posts from about 2010 or so.....DO NOT...use vinyl or shower curtain material. Yes... some of those are fine for UV...but UV is not the issue here.

Vinyl continues outgassing and shrinking daily for the rest of its life. That solvent that outgasses will turn the contact cement to a gooey mess. And eventually the vinyl will get crispy. Wrong stuff.

The Low density polyethylene film most are using should be fine....but if you are wondering why factory film feels thicker when its not.....its because its High density Polyethylene film. You can get this in many stores by the roll but you need to be specific about what you are buying. Read the label.
Ray

Thu Jul 05, 2018 5:15 pm

Behind a door card, showing uncut original vapor barrier:

Sun Sep 13, 2020 2:44 pm

Hello all,
as an update to this thread. I just finished my doors and did as Tcash shows in the prior picture (factory), except the following:
1) I used butyl rubber sealant tape (Fabral metal wall sealant tape from Home Depot- $5 for 40 feet- 1/4 inch wide)
2) I taped the flap instead of gluing. We'll see how it holds up.
The key item was that I wanted to be able to take the vapor barrier on and off as I assumed I'd be in there many times. It turns out I had to take the panels off to fix things 3 times, so good decision.

Key things to remember:
1) I had to add a seal around the vent (I forgot initially- see yellow line)
2) Make sure that for a '75 the blue slider is in there before the panel
3) I used Werksberg panels, so not even sure if vapor barrier was necessary, since they are plastic, but erred on the side of caution.
4) Make sure you look at the vapor barrier package before you buy. I thought I was getting clear but ended up with black. Didn't feel like returning it.

Pics
Initial bead (added more around vent- yellow line)

Vapor barrier cut-out (used packing tape to attach flap)

Vaper barrier installed (don't forget to cut-out around vent like shown in Tcash's pic

Close to the final product (except the cut-out for vent and the sliding lever should be there- recall I screwed up the first time).

Finally don't put the bead at the very edge as it will squeeze out, so pull it in a little from the edge.

Bill

Tue Nov 30, 2021 12:40 pm

I have just finished this job on both doors. It took me an age, but I was in no rush! Part of the reason it took so long was that I cleaned and serviced the door locks and check straps, and repainted the inside of the doors while I had it all exposed. (and went abroad for 10 weeks!)
Some top tips that might add to this thread:
I struggled to get thick enough plastic sheeting but I eventually found 36”x48” clear plastic rubble sacks (super heavy duty garbage bags). They were 0.006” (0.15mm) thick and after trying a few adhesive tapes I secured the inner flap with greenhouse/poly tunnel repair tape.
I made a couple of extra cuts in the template and reinforced them with the clear tape: one for the door opening rod, and one for the strut of the window mechanism (1977 bay).
I secured the plastic to the door with strong double sided tape. It sticks completely to the door, but the plastic sheet will peel off if needed.
I warmed the rubber grommets in hot water before fitting, and used the ball end of an Allen wrench to poke them into the holes in the door. Guide holes were made with an awl/spike.
End result seems good. Tight, tough sheet with no holes to let water through. I’ll post the problem I had with the door clips separately!

Tue Nov 30, 2021 12:47 pm

So, some of my old door clips were corroded or broken, so I had ordered new ones along with the rubber plugs.
I tried fitting the door card with all new clips, but they wouldn’t seat properly at all.
The old ones are brassy coloured, and the new ones silver. You can see that the ‘wings’ of the originals taper in at the end so that they can grip inside the rubber grommet. The new ones are parallel sided, so don’t grip at all!
I found a way of bending the tips (which are pretty stiff) by putting the tip of a torx wrench inside, heating with a blow torch and then nipping the tips in with pincer type pliers. Unfortunately, the whole clip is pretty fragile and so I ended up destroying as many as I altered, by snapping them in half!