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In trying to find sort some rattles in the doors I'm once again reminded of that horrible black gloop which holds on what seems to be an unnecessary sheet of plastic.

I suppose it's possible they're designed to do something worthwhile. What is it, and is it relevant in our climate, or can I just get rid of them and maybe get some Dynamat in there instead? If so, how do I clean off the gloop?

Its sikaflex. Should be able to be removed with some turps

Any downsides to removing the vapour barrier?

Dave,
This might be of some interest. www.trufitcarpets.com.au/resomat.htm
Greg.

The black stuff can be removed with white spirits (wear lots of gloves, the stuff is brutal on skin).

The plastic sheet keeps water from soaking the door card and going inside the car. As a result, can help to stop fogging on a rainy day.

My advice is leave the black stuff there; it gets everywhere, but I've not found a product that is as effective as it is in keeping that plastic sheet in place.

It's all there for a purpose- Mitch is spot on. The product is butyl mastic and it was available at one stage in tape form and it's available from Bunnings in cartridge form- I think it's Selleys but look it up. The plastic is working as a membrane and simply designed to prevent moisture eg running down windows and getting through to the door trims. A wet door trim is not good. It's common for old cars to have warped door trims due to water ingress. This system has been used for decades.

Car cos use it because it's cheap and effective and here is another reason -- because it can be removed and resealed in the field. If you use glues they set and cannot be resealed easily
Best bet is recut a plastic membrane if the old one is damaged and you can buy reinforced but supple see through film at garden nurseries and either use new butyl or re use the old.

How to clean up. Have on hand all the usual solvents and try them on small areas. Mitch is probably correct though kero may also work.

I realise the door must collect some water when it rains, from the outside seal against the window not being perfect. If the barrier is there to stop that water going into the door card, where does the water go instead?

There are drain holds in the bottom of the door.

J

I have removed the black sticky stuff with white spirits and replaced it with Sellys Butyl Mastic. Definitely not the same stuff. The Sellys product does not remain tacky; mine has hardened, and I have ende dup running gaffa tape around the edge of the plastic cause the sellys product was so useless

mitch_f1 wrote:.....Sellys Butyl Mastic. Definitely not the same stuff. ..... cause the sellys product was so useless

Thanks for the heads up.
I guess the product (or the formulation, but butyl mastic is butyl mastic!) may have change since obi-wan morlock first read about it in The Argus.


What you are after is a high solids, non hardening, non-drying, non-oxidising butyl sealant.
Ask a panel shop what they use, or contact Sika Australia (Automotive Aftermarket) for solutions.
I "think" the stuff used is Sikalastomer 711 but you will have to verify that.

FFG - you seem unaware that some products have been around for many decades and still work very well. Selleys- "Butyl Mastic is a synthetic resin, butyl rubber based mastic which forms a smooth tough skin, but remains permanently plastic underneath. It is available in 3 colours – White (off-white colour), Black and Grey. It is ideal for dustproofing cars, trucks, caravans, boats, etc. and is suitable for sealing cracks and gaps around brickwork, roofing, cladding, etc". I did mention butyl tape but I think it would be hard to source and the tube is convenient.

Moisture obviously gets into cavities and generally evaporates. A liner works in the most obvious way. Anyone who had trims off old cars will know its common place for the low cost backing board to deteriorate. The Selleys product is stocked at Bunnings. Good product with other uses and seems to last a very long time and apply with caulking gun.