Poll for Those with Paint Blistering / Bubbling Defect

[freefall_junkie]

My car probably isn't a very good litmus test, as it's garaged, doesn't get used in the wet unless I get caught out, and gets washed very carefully, very rarely with a hose.... yeah I know, a garage queen.

But, does anyone reading here, treat their car similarly, and still have blisters? Or do we think this is mostly a disease of the Emiras exposed to weather? ie, parked outside and driven in the rain, washed with a hose or power washer etc.

Thoughts??

I'm in a similar situation. No blisters yet, earlyish car, but garaged, washed carefully and rarely driven in the wet. I do wonder if this is just delaying the inevitable. On the other hand my car was built in November 22 but not delivered until the following February and there was clear evidence it had been stored outside. You would think 3 months stood in the rain through the depths of a British winter would be enough too induce blisters if they were going to happen. My car was one of a sizeable batch which had their delivery delayed around that time to address unspecified quality issues. Who knows, Lotus may even have had to replace the doors on some cars before they were handed over to the customer

 

[Speedluvver]

I'm the same 18 months old, 9K miles - has been driven in the wet, but not that much.. I do sometimes use a hose.. no blisters as yet - mine is yellow which I was told seemed to be the colour with the least blistering issues (by a dealer) - so I do wonder if it is paint related in some way....

 

[Beardedbradley]

I'm the same 18 months old, 9K miles - has been driven in the wet, but not that much.. I do sometimes use a hose.. no blisters as yet - mine is yellow which I was told seemed to be the colour with the least blistering issues (by a dealer) - so I do wonder if it is paint related in some way....

I did wonder if there’s a colour more prone to blisters or are the metallics worst than solid, but I now believe it’s widespread across the range. I haven’t personally seen a blistering yellow so would like to be wrong on my widespread statement. I live within 10miles of a Lotus dealership so have checked fairly frequently on stock my last visit, 3 used V6s the 2 Seneca Blue had blisters the Nimbus Grey didn’t, the Emira Turbos were all ok. I was loaned a Magma Red V6 manual 24reg that had its doors replaced before it came to me(unsure when it was built I had it in September).

 

[JonFuller]

I think if it were paint related, those with pull PPF would be way less likely to have issues, but I think plenty of folk with issues, have PPF, as a few have mentioned the warranty door replacement, included the re application of PPF.

I think that if it's moisture, it's coming through from the back of the skin somehow, or maybe even via the top edge by the window rubber, where it could be a trimmed, raw/rough edge (not visible), where the water 'wicks' in from the top and travels through the laminate.

Then again, if it's a chemical thing going on within the laminate, those that are gonna get it, are just gonna get it.

The fact that it seems to be appearing on the rear wings, albeit less frequently, I feel it's more likely a chemical issue, as those locations, unlike the doors, don't really have the perfect storm of a window rubber along the top edge that allows water to trickle down the back of the skin everytime it gets rained on, or washed.

Bloody cars, why do we do it to ourselves?

 

[Beachbum]

Bloody LOTUS, why do we do it to ourselves?

EFA

 

[SteveB]

Teijin supplies the doors, rear quarters and tailgate panels.

This press release when they won the contract hasn't aged well: 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.

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.”

 

[kitkat]

I stand corrected Still, only one out of a lot of US cars.

I’ve seen some others on other platforms unfortunately.

 

[Rupes]

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.”

Love these forums largely because of people like you who post an opinion based on some background/expertise to identify the issue.

So based on what you’re saying - a door skin that is cured properly and pure of imperfections (layman’s terms) shouldn’t blister because the underlying application was sound. This is true regardless of water ingress over time. Conversely, an improperly sealed door is almost certain to have blisters, even with minimal water intrusion, because it’s a “ticking time bomb.” Is that right?

This would at least explain how some cars in damp environments have gone years with no issues, and others see the blistering almost right away.

 

[SteveB]

Love these forums largely because of people like you who post an opinion based on some background/expertise to identify the issue.

So based on what you’re saying - a door skin that is cured properly and pure of imperfections (layman’s terms) then the amount of water ingress over time wouldn’t matter because the underlying application was sound which prevents any blistering. Conversely, an improperly sealed door is almost inevitable to have blisters even with minimal water intrusion because it’s a “ticking time bomb.” Is that right?

This would at least explain how some cars in damp environments have gone years with no issues, and others see the blistering almost right away.

Essentially yes that’s correct. If the polyester resin is pure (free of acidic impurities) then the presence of water and lack of effective door sealing would be less problematic (I.e. paint blisters would be less likely to form).

 

[Lotustoronto]

The factory dealing with the doors / composite parts surely are under very high scrutiny to fix the issue. I believe that the first UK builds in 22/early 23 would be the most affected. My suggestion is don't baby your Emira, drive it in the rain a bit and see what happens after a few months. You rather have the blistering while under warranty. As time goes on the QC should only get better. Also if this is about humidity and water penetration - our Florida Emira owners will be the one's for the best results on how late '23 / '24 builds have come along.

 

[scv]

So, if blistering occurs, at some point could not all of the chemical reaction resulting in CO2 gas/bubbles eventually be self limiting since all chemicals "used up" (pardon technical terminology)? Perhaps no more bubbles could form; at that time repairing surface defects and painting takes care of problem with no further "bubbles"?@SteveB your thoughts..........

 

[Foxy87]

Learning that the Elise S2 and the Evora had the same problem, there is probably a zero percent change Lotus is going to resolve the problem on the Emira. Looks like one has to live with it…

 

[SteveB]

So, if blistering occurs, at some point could not all of the chemical reaction resulting in CO2 gas/bubbles eventually be self limiting since all chemicals "used up" (pardon technical terminology)? Perhaps no more bubbles could form; at that time repairing surface defects and painting takes care of problem with no further "bubbles"?@SteveB your thoughts..........

That’s an interesting question but I suspect the reality is that once there is water penetration into the GRP composite, CO2 generation and paint bubble formation will continue for many years unless preventative steps are taken. This is likely the reason the approved warranty fix is a completely new door.

To give an indication of the magnitude of the problem (with many assumptions!): assuming an Emira door weighs 10kg (resin + glass reinforcement) and the resin:glass fibre weight ratio is 60:40, then a 10kg door will contain 6kg cured resin. A bit of google research suggests when powdered calcium carbonate is used to modify the mechanical and thermal properties of a polyester resin, it is used at about 20% (w/w). We know from the Teijin press release that their method of construction uses less calcium carbonate powder than normal, so let’s assume 10% w/w, meaning a 10kg (assumed) Emira door would contain 600g powdered calcium carbonate. If fully reacted with acid this would produce 134.4 litres of CO2! Given that even in the worst cases of paint bubbling, the total volume of the bubbles is 1-2 ml at most, there is massive potential for paint bubbles to form over time, even if a sizeable volume vented on the inside of the panel rather than the outside.

The limiting factor here is the amount of acidic impurities trapped in the resin. Let’s assume that the 6kg cured resin contains just 1% of acidic impurities (60g). If the acidic impurity was Maleic acid then there would be enough present to generate 11.5 litres of CO2 after reaction with calcium carbonate. This is still a very large volume compared to the size of a paint bubble! Also, we know from photos of doors that have suffered from paint bubbles that they appear in very localised areas (usually in a row just below the window glass where there is an internal shelf that can collect water). So, even if all of the acidic residues were exhausted in one localised area, paint bubbles could still form in other areas at a later date (unless steps taken to remove any water present and prevent further water ingress).

Finally, it’s worth while remembering that calcium carbonate is added to polyester resin for a reason and if a significant amount is converted to CO2, there will likely be consequences for door strength & integrity!

 

[nelly111s]

There’s been a few people on here saying that Lotus hasn’t modified the doors, they’re just putting the same ones on again. I doubt this, but has anyone got any facts?
Do the newer doors have a different part number ( or even modification or alternate designation number) than the old ones? Anyone got access (via a dealer?) to the parts list?

 

[Rupes]

I don’t think it would be a new part. Just a better sealant/curing process.

 

[Enut]

There’s been a few people on here saying that Lotus hasn’t modified the doors, they’re just putting the same ones on again. I doubt this, but has anyone got any facts?
Do the newer doors have a different part number ( or even modification or alternate designation number) than the old ones? Anyone got access (via a dealer?) to the parts list?

I don't know the answer but have seen at least one report of replaced doors also suffering the same bubbling, suggesting that they certainly didn't solve the problem on that new door!

 

[nelly111s]

I don’t think it would be a new part. Just a better sealant/curing process.

In my experience (in a different industry) there would be a way to differentiate the items. I guess if the manufacturer could prove a different process from a specific date, it could be done by that if the parts have a date code too. But replacing doors with ones from a known “faulty batch” would be financially unwise.

 

[scv]

That’s an interesting question but I suspect the reality is that once there is water penetration into the GRP composite, CO2 generation and paint bubble formation will continue for many years unless preventative steps are taken. This is likely the reason the approved warranty fix is a completely new door.

To give an indication of the magnitude of the problem (with many assumptions!): assuming an Emira door weighs 10kg (resin + glass reinforcement) and the resin:glass fibre weight ratio is 60:40, then a 10kg door will contain 6kg cured resin. A bit of google research suggests when powdered calcium carbonate is used to modify the mechanical and thermal properties of a polyester resin, it is used at about 20% (w/w). We know from the Teijin press release that their method of construction uses less calcium carbonate powder than normal, so let’s assume 10% w/w, meaning a 10kg (assumed) Emira door would contain 600g powdered calcium carbonate. If fully reacted with acid this would produce 134.4 litres of CO2! Given that even in the worst cases of paint bubbling, the total volume of the bubbles is 1-2 ml at most, there is massive potential for paint bubbles to form over time, even if a sizeable volume vented on the inside of the panel rather than the outside.

The limiting factor here is the amount of acidic impurities trapped in the resin. Let’s assume that the 6kg cured resin contains just 1% of acidic impurities (60g). If the acidic impurity was Maleic acid then there would be enough present to generate 11.5 litres of CO2 after reaction with calcium carbonate. This is still a very large volume compared to the size of a paint bubble! Also, we know from photos of doors that have suffered from paint bubbles that they appear in very localised areas (usually in a row just below the window glass where there is an internal shelf that can collect water). So, even if all of the acidic residues were exhausted in one localised area, paint bubbles could still form in other areas at a later date (unless steps taken to remove any water present and prevent further water ingress).

Finally, it’s worth while remembering that calcium carbonate is added to polyester resin for a reason and if a significant amount is converted to CO2, there will likely be consequences for door strength & integrity!

Thanks, understand the aspect of volume....not encouraging; unless Lotus has taken definitive steps to fix. Do you, or anyone, have any factual info on anything Lotus may have done to correct problem?

 

[FST]

Unfortunately my car finally has started to show bubbles on the rear engine bay area, blisters on the gaps between front fender and bumper (pressed tight to each other) and bumper show weird stripes and marks

 

[Porter]

Unfortunately my car finally has started to show bubbles on the rear engine bay area, blisters on the gaps between front fender and bumper (pressed tight to each other) and bumper show weird stripes and marks

None of those areas are affected by the Teijin GRP issues. Sounds like your car may have something different going on.