Poll for Those with Paint Blistering / Bubbling Defect

[912Matt]

All corrected under warranty with no charge to the owner. An absolute pain but they sort them.

I like your optimism, but in my case at least it hasn’t been that straightforward. My car went in in October for two new doors, and several other issues to be rectified.
Some issues were fixed, but not all, and even came back with a new issue which developed whilst with Lotus!
Only one door was replaced (still no explanation as to why), and that wasn’t done well - alignment is awful, and whistles at anything over 60 mph. Can’t believe the dealer thought this was acceptable!!
Awaiting response from LCC, but have lost faith in my local Lotus centre, and have asked if the car can go back to Hethel to be sorted.

 

[JonFuller]

I stopped by Bell & Collvil today.
There was a 2024 DV Emira on the forecourt, with very bad blistering on one door.
Odd thing was, the area in question had some lines, the sort you see where in prep, the sanding has feathered the edge of paint, primer etc, and when the topcoat has been applied, and cures, it shrinks and you see a line in the paint along the feathered edge, or maybe in a circle if a small area has been sanded.
Well on this car, all of the blisters were along these visible lines in the paint.

So maybe, the cars affected, are ones that had more prep & sanding done to the door skin, and in some cases, this gas broken through some primer barrier or summat, and the issue occurs where the substrate is exposed to the final paint coating?

See short video, not sure if it’ll be easy to see in vid, you’ll need it full screen.

 

[Man.v.Cars]

Further details of the Teijin press release can be found here: https://www.compositesworld.com/new...-supplies-exterior-body-panels-to-lotus-emira

Note a different process is used to produce the rear panels/tailgate vs the doors and rear quarter panels.

Reading this article I was intrigued by the use of calcium carbonate in the composite mix (to improve its mechanical properties). However this additive could potentially play a role in the formation of paint bubbles.

Firstly, I do have a chemistry background and some knowledge of polymers - but the following is just a possible explanation - not proven fact!

Polyester resin (of the type often used in the production of glass fibre composites) is commonly formed by reaction of ethylene glycol with maleic anhydride (itself produced by dehydration of maleic acid) to produce an unsaturated polyester resin. This is is commonly dissolved in styrene to form a viscous resin solution. The unsaturated polyester resin/styrene mix is cured by addition of a free radical initiator (e.g. a peroxide) to produce a solid, 3-dimensional resin. If the maleic anhydride was not sufficiently pure or polyester resin synthesis or curing was not properly controlled, then the resulting cured resin could contain acidic compounds (e.g. maleic acid). Also, some fire retardants sometimes used in the production of composites are also acidic. After water penetration (e.g. rain water or condensation running down an improperly sealed inner surface of a Emira door) these acidic compounds could be mobilised within the resin and interact with the calcium carbonate particles. The end result would be the generation of CO2 within the resin composite. Over time the internal pressure will increase and eventually gas will escape through microfissures to the surface - resulting in a paint bubble!

IF this is the source of the paint bubbles, their occurrence will be somewhat random as dependent on several variables such as batch-batch variation of the resin used, how well controlled the curing process is, how well sealed the inside of the panels are, extent of water exposure/water ingress, etc. It would unlikely be affected by the type of pigment (colour) used in the paint mix.

Again, IF this is the explanation for the formation of paint bubbles, preventative measures could include replacement panels made using different inorganic particles that do not react with acids (e.g. calcium fluoride) or better sealing to prevent water ingress. There has been some speculation that a different internal coating is used on later doors. The only way to treat an existing door and prevent the formation of new bubbles would be to completely dry the door (in a vacuum oven) and completely seal the inner surface to prevent any new ingress of water.

All of this is somewhat ironic given the reason Lotus used Teijin panels was: “This treatment technology results in a more robust resin mix making molded parts more resistant to handling damage, preventing micro-cracks that cause paint pops, pits and blistering, and improving paint adhesion and bonding characteristics.”

Sounds plausible, though every door I've seen (including my own) are affected in exactly the same places ie top of the door, handle, below the wing mirror and on the bottom edge. Perhaps the treatment isn't applied evenly near the edges of the door.

 

[Man.v.Cars]

If doors from the earliest build date to now are having this issue - it doesn’t seem like to me this is a localized problem or problem with a batch of doors - it seems to me this is an intrinsic design or production flaw with the doors - which would mean that it’s not a question of if but a question of when moisture gets into the panel and starts blistering the paint on any Emira. How could this be limited to a single batch of doors when doors produced from the very beginning of production to right now are still having this issue?

Second, since cars from initial delivery to now are still having this problem, it’s obvious Lotus has been aware of this issue and has been replacing doors on cars from mid 2023 to now. Which means that they have been aware of the defective door design, yet have continued to pump out cars with the defective doors to customers.

On top of that, Lotus has been given zero acknowledgment that the replacement doors they’re replacing the defective doors are different in any way. Since lotus has said nothing I would have to assume they are not because if they were, why wouldn’t they be using this revised design in the current build cars when they’ve known about this issue since mid 2023?

With the evidence above, I’m shocked that there hasn’t been any movement or pressure from owners toward Lotus on some sort of answer or solution to this. I understand that these cars are not perfect but accepting that replacing doors and doing the accompanying paintwork is a part of long term ownership is insane to me. IF this is an inherent design or production flaw across all doors (I can’t logically see any other possibility when cars from all build dates are having issues), what’s going to happen to values of these cars coming out of warranty once it becomes well known in another 18-24 months that this is a inherent defect with no resolution?

I've challenged Lotus CS on their website stating 5 year warranty, recently changed to 3 years, on paintwork. They attempted to say it was 'just a mistake', and not relevant, until I pointed out it stated 5 years warranty for 3+ years while they were selling cars direct. This is easily interpreted as forming a part of the contract as it would have swayed buyers to enter into a contract to buy.

There is also the avenue that it is an inherent fault known by Lotus, which would also likely be covered by consumer laws in the UK, not sure about other jurisdictions.

I was told that it is being discussed at Lotus to get a workable solution, I gave them one so that is being considered. We shall see what happens.

 

[Lotustoronto]

Sounds plausible, though every door I've seen (including my own) are affected in exactly the same places ie top of the door, handle, below the wing mirror and on the bottom edge. Perhaps the treatment isn't applied evenly near the edges of the door.

There must be something happening at the factory in this specific area. It does seem strange it is predominantly on the upper door section. Could contamination from handling the doors in shipping prior to painting cause this? I suspect the top of the doors is a good grab spot for loading / unloading.

 

[Man.v.Cars]

There must be something happening at the factory in this specific area. It does seem strange it is predominantly on the upper door section. Could contamination from handling the doors in shipping prior to painting cause this? I suspect the top of the doors is a good grab spot for loading / unloading.

Again, plausible. Edges and the hole where the handles are fitted would be good grab points.

 

[jonsealsportscars]

Further details of the Teijin press release can be found here: https://www.compositesworld.com/new...-supplies-exterior-body-panels-to-lotus-emira

Note a different process is used to produce the rear panels/tailgate vs the doors and rear quarter panels.

Reading this article I was intrigued by the use of calcium carbonate in the composite mix (to improve its mechanical properties). However this additive could potentially play a role in the formation of paint bubbles.

Firstly, I do have a chemistry background and some knowledge of polymers - but the following is just a possible explanation - not proven fact!

Polyester resin (of the type often used in the production of glass fibre composites) is commonly formed by reaction of ethylene glycol with maleic anhydride (itself produced by dehydration of maleic acid) to produce an unsaturated polyester resin. This is is commonly dissolved in styrene to form a viscous resin solution. The unsaturated polyester resin/styrene mix is cured by addition of a free radical initiator (e.g. a peroxide) to produce a solid, 3-dimensional resin. If the maleic anhydride was not sufficiently pure or polyester resin synthesis or curing was not properly controlled, then the resulting cured resin could contain acidic compounds (e.g. maleic acid). Also, some fire retardants sometimes used in the production of composites are also acidic. After water penetration (e.g. rain water or condensation running down an improperly sealed inner surface of a Emira door) these acidic compounds could be mobilised within the resin and interact with the calcium carbonate particles. The end result would be the generation of CO2 within the resin composite. Over time the internal pressure will increase and eventually gas will escape through microfissures to the surface - resulting in a paint bubble!

IF this is the source of the paint bubbles, their occurrence will be somewhat random as dependent on several variables such as batch-batch variation of the resin used, how well controlled the curing process is, how well sealed the inside of the panels are, extent of water exposure/water ingress, etc. It would unlikely be affected by the type of pigment (colour) used in the paint mix.

Again, IF this is the explanation for the formation of paint bubbles, preventative measures could include replacement panels made using different inorganic particles that do not react with acids (e.g. calcium fluoride) or better sealing to prevent water ingress. There has been some speculation that a different internal coating is used on later doors. The only way to treat an existing door and prevent the formation of new bubbles would be to completely dry the door (in a vacuum oven) and completely seal the inner surface to prevent any new ingress of water.

All of this is somewhat ironic given the reason Lotus used Teijin panels was: “This treatment technology results in a more robust resin mix making molded parts more resistant to handling damage, preventing micro-cracks that cause paint pops, pits and blistering, and improving paint adhesion and bonding characteristics.”

This is a very interesting article I assumed Lotus would be making their own panels in house. To read that they have returned to Closed Mould/Injeciton moulding beggars belief. This is the system they used on the S2 Elise and VX220. You know the ones that bubbled and blistered as soon as they got frost on them?

SMC moulding is done purely for cost saving and time saving. They should be making these panels hand lay. All the cars from S2 Exige onwards went back to hand lay and other than S1 Evoras I have never seen paint blistering on any S3 only a slight bit for some reason occurs on V6 Exige hinge covers now and again. Hand lay panels are also much lighter.

It's also astonishing that they are having this stuff done in the USA when we have a vibrant and world leading composites sector right here in the UK.

SMC moulding creates a sponge as the rear of the panel isn't "sealed" like it is with hand lay. When the GRP is hand laid and resin worked through the layers it ends up with a nice smooth layer of resin on the rear of the panel which sets and although not fully waterproof it is 99% better than SMC and it won't allow moisture to the painted surface which is basically whats happening here. One Emira I saw had just had uncleared material painted over but the pics on this thread in the main just look like capillary water thats interacted with the paint. This issue will never be solved with the panels produced in this way.

 

[Man.v.Cars]

This is a very interesting article I assumed Lotus would be making their own panels in house. To read that they have returned to Closed Mould/Injeciton moulding beggars belief. This is the system they used on the S2 Elise and VX220. You know the ones that bubbled and blistered as soon as they got frost on them?

SMC moulding is done purely for cost saving and time saving. They should be making these panels hand lay. All the cars from S2 Exige onwards went back to hand lay and other than S1 Evoras I have never seen paint blistering on any S3 only a slight bit for some reason occurs on V6 Exige hinge covers now and again. Hand lay panels are also much lighter.

It's also astonishing that they are having this stuff done in the USA when we have a vibrant and world leading composites sector right here in the UK.

SMC moulding creates a sponge as the rear of the panel isn't "sealed" like it is with hand lay. When the GRP is hand laid and resin worked through the layers it ends up with a nice smooth layer of resin on the rear of the panel which sets and although not fully waterproof it is 99% better than SMC and it won't allow moisture to the painted surface which is basically whats happening here. One Emira I saw had just had uncleared material painted over but the pics on this thread in the main just look like capillary water thats interacted with the paint. This issue will never be solved with the panels produced in this way.

They're made in France, transported to Portugal for finishing and then shipped to the UK, as are the rear 1/4s and hatch.

 

[kitkat]

This is a very interesting article I assumed Lotus would be making their own panels in house. To read that they have returned to Closed Mould/Injeciton moulding beggars belief. This is the system they used on the S2 Elise and VX220. You know the ones that bubbled and blistered as soon as they got frost on them?

SMC moulding is done purely for cost saving and time saving. They should be making these panels hand lay. All the cars from S2 Exige onwards went back to hand lay and other than S1 Evoras I have never seen paint blistering on any S3 only a slight bit for some reason occurs on V6 Exige hinge covers now and again. Hand lay panels are also much lighter.

It's also astonishing that they are having this stuff done in the USA when we have a vibrant and world leading composites sector right here in the UK.

SMC moulding creates a sponge as the rear of the panel isn't "sealed" like it is with hand lay. When the GRP is hand laid and resin worked through the layers it ends up with a nice smooth layer of resin on the rear of the panel which sets and although not fully waterproof it is 99% better than SMC and it won't allow moisture to the painted surface which is basically whats happening here. One Emira I saw had just had uncleared material painted over but the pics on this thread in the main just look like capillary water thats interacted with the paint. This issue will never be solved with the panels produced in this way.

As owners, what can be done?

 

[Porter]

This is a very interesting article I assumed Lotus would be making their own panels in house. To read that they have returned to Closed Mould/Injeciton moulding beggars belief. This is the system they used on the S2 Elise and VX220. You know the ones that bubbled and blistered as soon as they got frost on them?

SMC moulding is done purely for cost saving and time saving. They should be making these panels hand lay. All the cars from S2 Exige onwards went back to hand lay and other than S1 Evoras I have never seen paint blistering on any S3 only a slight bit for some reason occurs on V6 Exige hinge covers now and again. Hand lay panels are also much lighter.

It's also astonishing that they are having this stuff done in the USA when we have a vibrant and world leading composites sector right here in the UK.

SMC moulding creates a sponge as the rear of the panel isn't "sealed" like it is with hand lay. When the GRP is hand laid and resin worked through the layers it ends up with a nice smooth layer of resin on the rear of the panel which sets and although not fully waterproof it is 99% better than SMC and it won't allow moisture to the painted surface which is basically whats happening here. One Emira I saw had just had uncleared material painted over but the pics on this thread in the main just look like capillary water thats interacted with the paint. This issue will never be solved with the panels produced in this way.

You're making assumptions based on an older, unrelated process. This is a very different form of GRP called TCA Ultra Lite, and is not injection molded. It's also being produced in Portugal and France, not in the US. Teijin expanded the production to multiple production sites around the world after their acquisition of Continental Structural Plastics.

Here's a video showing the Teijin process that shows the details of the production steps.



And here's an overview of Teijin's European operations.

 

[Nick in Sydney]

You're making assumptions based on an older, unrelated process. This is a very different form of GRP called TCA Ultra Lite, and is not injection molded.

Exactly! The sophistication of this SMC has little in common with the product and process from 20 years ago. Interesting videos, thanks for posting them.

Because Lotus seems unwilling to openly confirm what it is the root cause of blistering on the Emira, we are all guessing to some degree. For example, it could still turn out that it's not a Teijin manufacturing issue, but a Lotus problem like poor paint preparation, handling damage or poor storage methods. We just don't know.

 

[jonsealsportscars]

Interesting however the problem is still the same as CSM in that they are just lobbing chopped rovings into the structure. Laminating is the best and highest quality that you can get but it's way way more labour intensive of course.

It clearly doesn't work in any case as you can see by the number of cars that have issues. If they had stuck to the 15 year tried and tested formula they wouldn't have had the issues. The paint/lamination quality was the best in the world on the last of the heritage cars and this is a big step back.