Water membrane

[crestima]

Well if you can get condensation in a headlight then you can get it anywhere .lol

You're probably right buddy, and perhaps I'm the one who hasn't taken enough lessons in chemistry. However, one thing is for sure, our 911's components deal with condensation way better. I just hope Lotus comes up with better sealed parts so that we can stop placing umbrellas over them.

 

[crestima]

I have yet to get my Emira delivered and when I decided to look at this growing thread and figure out what it's about. Being in So Cal with virtually no rain, ex HVAC guy for 36 years, I look forward to seeing what is in mine!!

Thanks for the advanced work and solutions here!

Maybe a scorpion or two?

 

[Kimmax]

Okay, so here's the thing

Turns out I don't actually have a "Lotus"-supplied membrane in my car. My mechanic rolled his own solution, because when we ran into the water ingress issues the Lotus membrane wasn't a thing yet. In my case, all the important parts and cables were wrapped individually in plastic. To do that you have to take the front apart. No way to reach otherwise.

I still cut a membrane and left the existing solution as-is. I used EPDM. Material is great but I'm not really happy with how it turned out. It's not a great fit and is basically just thrown in there. I managed to secure it somewhat using the latch assembly in the middle, but dealing with the "puddle" spots isn't easy.

The best cut I came up with ignores the Lotus style and instead runs full width, side to side. For now I've tucked the sheet under the fenders. A better approach would be to fasten it with the plastic clips from the housing along the fenders and somehow secure it further up under the bottom windshield plastic, but I didn't have time to work that out.

Since the membrane turned out way bigger than I expected, it won't fit our laser cutter. I reached out to a few companies nearby that might be able to do it, but interest is understandably low. Right now guesstimated I'd have to ask something like €80–100 per piece, which is probably too much. I could cut them by hand, but that's more work than I anticipated, and I wouldn't want to ship something that isn't perfect. So I'd say you're still better off doing this yourself. I can reconsider if demand is high.

I did, however, already do the technical drawing, which I'll attach. A few (untested) changes I'd make:

• Increase the width to 125 cm
• 10 cm on both sides at the top, before the curve starts, due to the longer width
• Offset the hole 2–3 cm inward

That gives you more material to bring up the walls and thus a tighter fit around the hole.

 

[Stevie1464]

Hi,
First off that looks like the best well thought out version thus far. I for one would be more than happy to pay for one from you - imperfect or not!!

 

[jamesbxxx]

Will you be posting an updated technical diagram? Very useful information!

 

[Kimmax]

Will you be posting an updated technical diagram? Very useful information!

I'll change & upload it tomorrow

 

[zoomtt]

Hi,
First off that looks like the best well thought out version thus far. I for one would be more than happy to pay for one from you - imperfect or not!!

same here, I would be fine with a hand cut one. Nobody will see this anyways.

 

[KJD]

The membrane is a much better fit if the windscreen gutter piece is removed.

Comes off easily. Remove the wipers, the washer jets and some bolts and it unclips from the bottom of the screen.
Then there’s much more space to manoeuvre the sheet into a good position.

 

[MiamiBlue]

Just to add to this thread. My Lotus membrane lasted about 2 years before it cracked, failed and needed replaced.
The Lotus solution is only a temporary fix.

 

[Stevie1464]

The membrane is a much better fit if the windscreen gutter piece is removed.

View attachment 83402

Comes off easily. Remove the wipers, the washer jets and some bolts and it unclips from the bottom of the screen.
Then there’s much more space to manoeuvre the sheet into a good position

Holy water membrane Batman!! I think you've solved the riddle!!! How's the pooling? I take it there isn't much due to how you've fitted it?

 

[Kimmax]

The membrane is a much better fit if the windscreen gutter piece is removed.

View attachment 83402

Comes off easily. Remove the wipers, the washer jets and some bolts and it unclips from the bottom of the screen.
Then there’s much more space to manoeuvre the sheet into a good position.

That's what I thought! Anyway to fasten it under the top, or still just a tuck?

 

[SJones]

Just checked my membrane which was installed around June 2024 a not long after taking delivery. I live in central Florida, big heat and big rain in summer. 11,000 + miles on car driven year round (garaged). Membrane was found to be in very good condition, flexible and no cracks. The garage it sits in when not being driven averages 105 degrees during summer days, so if heat alone causes the degradation you would think my car would be a prime candidate.

 

[Stevie1464]

Just checked my membrane which was installed around June 2024 a not long after taking delivery. I live in central Florida, big heat and big rain in summer. 11,000 + miles on car driven year round (garaged). Membrane was found to be in very good condition, flexible and no cracks. The garage it sits in when not being driven averages 105 degrees during summer days, so if heat alone causes the degradation you would think my car would be a prime candidate.

Your garage sounds like 'The cooler' that Steve McQueen kept getting put in in The Great Escape!!

 

[Nelumbo]

That is strange. I'm in Northern California and the weather is mild, but my membrane was cracked and caused problems for my AC unit. It's getting looked at by the dealer but they've been silent for a few week now.

 

[Savanna7]

I mean, rubber is petroleum-based. Wet vs Dry heat, right? Florida = wet heat. So long as it's not in direct sunlight, theoretically it shouldn't "dry" out. California is the opposite......

Or everything I just said is completely rubbish. idk lol

 

[geoffbland]

Judging by where the cracks were on my bib I suspect it's not temperature but vibration/movement. The cracks on my formed where the creases were in the bid and where the bib was folded over things. So places that would be flexing the most with the cars movement.
Either way I will be replacing mine with silicone sheet, this is more expensive but way more durable and longer lasting than any of the alternatives.

 

[Nelumbo]

I think it’s more likely due to the poor quality or choice of material. Rubber grades span the gamut, I presume. May not even be real rubber, lol.

 

[Stevie1464]

I think it’s more likely due to the poor quality or choice of material. Rubber grades span the gamut, I presume. May not even be real rubber, lol.

Vegan friendly rubber!!

 

[StopLoss]

That is strange. I'm in Northern California and the weather is mild, but my membrane was cracked and caused problems for my AC unit. It's getting looked at by the dealer but they've been silent for a few week now.

May I ask which dealer?

 

[crestima]

Just checked my membrane which was installed around June 2024 a not long after taking delivery. I live in central Florida, big heat and big rain in summer. 11,000 + miles on car driven year round (garaged). Membrane was found to be in very good condition, flexible and no cracks. The garage it sits in when not being driven averages 105 degrees during summer days, so if heat alone causes the degradation you would think my car would be a prime candidate.

Go figure. Mine had the first shroud installed by my Lotus dealer around the same time, in mid 2024, and I also happen to live in Florida (Miami more specifically), so our weather patterns shouldn't differ by much. My Emira is also garaged yet the rubber was degraded and cracked to the point that recently I decided to install my DYI version. I made one of what I hope to be a much better quality neoprene material and coincidentally along similar lines and dimensions shown in @Kimmax's post above # 123.