Painting an i3's Roof

[alohart]

I would like to paint the roof of our 2021 i3 Galvanic Gold to match its exterior color. BMW of Honolulu sent me to its 2 local BMW-approved body shops so that I could discuss what I want to do and to get cost and scheduling estimates. The first body shop refused to paint the roof claiming that BMW doesn't support painting CFRP. He claimed that the primer, paint, or whatever would damage CFRP over time. Maybe he just wanted the roof of our i3 to delaminate so that he could replace it for $9k! He told me that he had replaced several delaminated i3 roofs.

The second body shop didn't know whether CFRP could be painted but would check. He told me that the roof antenna and roof side trim would need to be removed. I told him that the antenna is bonded to the CFRP and wouldn't likely adhere to paint as strongly. Also, it was fine with me if the roof was painted only to the edges of the rubber side trim. I wanted the antenna and side trim masked and painted around. He told me that they wouldn't offer a warranty if all trim wasn't removed prior to painting. Jeez, these guys must not want the work, or maybe they want to create unnecessary work so that they can charge more.

I'm beginning to favor wrapping rather than painting. Unfortunately, the shop that did a great job wrapping the roof of our 2019 i3 has no more metallic silver vinyl in stock so would have to special order a roll. They charge $200 for a special order plus the installation cost, $650 total, which is pretty expensive for a roof wrap.

Do you know whether CFRP can be painted without damaging it?

 

[Dutchi3]

Maybe with water based lacquer?

 

[alohart]

Maybe with water based lacquer?

I was under the impression, maybe falsely, that auto paints these days are water-based to eliminate the volatile petrochemical solvents in past paints. Anyone know for sure?

I could understand that petrochemical solvents might damage the CFRP clear coat, but that doesn't seem likely for a water-based paint on a roof that is designed to be fine when wet.

 

[tongsli]

I know you want to paint it, but thought I'd share some info

https://www.m3post.com/forums/showthread.php?t=1406986

https://www.bmw.com/en/performance/carbon-fiber-in-a-car.html

 

[jreyna06]

I would like to paint the roof of our 2021 i3 Galvanic Gold to match its exterior color. BMW of Honolulu sent me to its 2 local BMW-approved body shops so that I could discuss what I want to do and to get cost and scheduling estimates. The first body shop refused to paint the roof claiming that BMW doesn't support painting CFRP. He claimed that the primer, paint, or whatever would damage CFRP over time. Maybe he just wanted the roof of our i3 to delaminate so that he could replace it for $9k! He told me that he had replaced several delaminated i3 roofs.

The second body shop didn't know whether CFRP could be painted but would check. He told me that the roof antenna and roof side trim would need to be removed. I told him that the antenna is bonded to the CFRP and wouldn't likely adhere to paint as strongly. Also, it was fine with me if the roof was painted only to the edges of the rubber side trim. I wanted the antenna and side trim masked and painted around. He told me that they wouldn't offer a warranty if all trim wasn't removed prior to painting. Jeez, these guys must not want the work, or maybe they want to create unnecessary work so that they can charge more.

I'm beginning to favor wrapping rather than painting. Unfortunately, the shop that did a great job wrapping the roof of our 2019 i3 has no more metallic silver vinyl in stock so would have to special order a roll. They charge $200 for a special order plus the installation cost, $650 total, which is pretty expensive for a roof wrap.

Do you know whether CFRP can be painted without damaging it?

oof. no way.
my roof delaminated in February. right-a-way i investigated and i found a good paint shop.
first attempt was to try and save the look of the roof by sanding then spraying several coats of clearcoat. the discoloration of the roof was too noticeable and we went with the back up plan. sand back down do the fiber and do two coats of gloss black to match the car and a coat of clear. this thing looked like glass it looked great. if you skip step one... going straight to sanding and painting it should be about $500 USD. and you should be good
i opted out for going back to that shop a couple of months later and getting the roof wrapped in a white carbon fiber 3M wrap. $450 since it was special order... could have been as cheap as $350 if i would have chosen an option in stock. my advise, dont try and safe the roof.

 

[808Pants]

oof. no way.
my roof delaminated in February. right-a-way i investigated and i found a good paint shop.
first attempt was to try and save the look of the roof by sanding then spraying several coats of clearcoat. the discoloration of the roof was too noticeable and we went with the back up plan. sand back down do the fiber and do two coats of gloss black to match the car and a coat of clear. this thing looked like glass it looked great. if you skip step one... going straight to sanding and painting it should be about $500 USD. and you should be good
i opted out for going back to that shop a couple of months later and getting the roof wrapped in a white carbon fiber 3M wrap. $450 since it was special order... could have been as cheap as $350 if i would have chosen an option in stock. my advise, dont try and safe the roof.

I was under the impression, maybe falsely, that auto paints these days are water-based to eliminate the volatile petrochemical solvents in past paints. Anyone know for sure?

I could understand that petrochemical solvents might damage the CFRP clear coat, but that doesn't seem likely for a water-based paint on a roof that is designed to be fine when wet.

Hey Art -

Industrial and auto coatings are still mostly solvent-based. (Not directly relevant, but your average paint booth doesn't do anything to capture those emissions; it just filters incoming air for particulate, and blows the unfiltered solvent-laden exhaust out upward, to avoid being a direct nuisance to neighbors.) But back to the point, I've sprayed solvent-based coatings on FRP (not so much CFRP, but same-same) on many, many occasions over the years with no deleterious results. That'd be old-school polyester (surfboard) resin composite, as well as low-odor epoxy resin items. They're completely inert once cured, and ideal surfaces to spray because they're disinclined to contain any moisture and certainly not going to rust/corrode under a coating. You can't hurt them with any solvent you'd normally use in such an endeavor, so I don't know what that guy was talking about (I mean, were they going to slather methylene-chloride-based paint-remover on it to start with? Yeah, that might cause a problem...)

I've got nothing for facilities, or I'd be spraying my own (probably this weekend) - been kicking around the idea of using waterborne/based just to avoid the solvent mess/cleanup, but even that's not such a big deal. (Maybe at the new house, which has an actual garage...)

Since you're going with a solid color (metallic gold) the question will come up as to whether you'll want a two-stage (color followed by clear) which I think even after all these years can't be guaranteed to peel (clear flakes off in the UV) but you can get a really good gloss out of a single-stage, even if it doesn't have quite the depth of the two-stage.

I wish I could recommend a particular body shop, but I'm totally out of touch with them these days.

BTW have you come across details on how to remove the three adjacent panels (left/right/back of the roof?) I'm pretty sure that's in my near future - can't stand the idea of masking off rubber flaps and letting overspray drift into those channels if I can avoid it. If you find another shop you trust, they'd probably consider doing the same - if you can bring them up to speed.

 

[rcpmac]

The Vivid carbon fiber vinyl in white (or black) 5'x6' is about $50 at amazon. Looks like a pretty simple project to me especially as the ends roll down and the sides tuck under the rubber gasket. VVIVID® XPO White Carbon Fiber Car Wrap Vinyl Roll with Air Release Technology (6ft x 5ft) | $45.98

 

[tongsli]

I can confirm the FROZEN Grey metallic color code.

BMW Frozen Pure Grey Metallic C5A Touch Up Paint​

I have received the paint from www.touchupdirect.com and have used it to paint the front bumper trim pieces. It's an exact match.

Hope this helps

Lito

 

[AlanfromBigEasy]

I would like to paint the roof of our 2021 i3 Galvanic Gold to match its exterior color. BMW of Honolulu sent me to its 2 local BMW-approved body shops so that I could discuss what I want to do and to get cost and scheduling estimates. The first body shop refused to paint the roof claiming that BMW doesn't support painting CFRP. He claimed that the primer, paint, or whatever would damage CFRP over time. Maybe he just wanted the roof of our i3 to delaminate so that he could replace it for $9k! He told me that he had replaced several delaminated i3 roofs.

The second body shop didn't know whether CFRP could be painted but would check. He told me that the roof antenna and roof side trim would need to be removed. I told him that the antenna is bonded to the CFRP and wouldn't likely adhere to paint as strongly. Also, it was fine with me if the roof was painted only to the edges of the rubber side trim. I wanted the antenna and side trim masked and painted around. He told me that they wouldn't offer a warranty if all trim wasn't removed prior to painting. Jeez, these guys must not want the work, or maybe they want to create unnecessary work so that they can charge more.

I'm beginning to favor wrapping rather than painting. Unfortunately, the shop that did a great job wrapping the roof of our 2019 i3 has no more metallic silver vinyl in stock so would have to special order a roll. They charge $200 for a special order plus the installation cost, $650 total, which is pretty expensive for a roof wrap.

Do you know whether CFRP can be painted without damaging it?

I have had both my 2015 & 2021 i3 painted white by a body shop with CFRP experience (Vargas of New Orleans). He first applied a sealing coat, waited a day, than painted BMW white. He told me not to touch it for a month to allow the seal coat to evaporate out.

Look for CFRP experience.

5 years after painting the 2015, it still looks good.
The body shop masked around the antenna.

 

[alohart]

I have had both my 2015 & 2021 i3 painted white by a body shop with CFRP experience (Vargas of New Orleans). He first applied a sealing coat, waited a day, than painted BMW white. He told me not to touch it for a month to allow the seal coat to evaporate out.

Look for CFRP experience.

5 years after painting the 2015, it still looks good.
The body shop masked around the antenna.

I sent A. Vargas Body Shop an email message requesting details of your roof paint job but haven't received a response yet.

Did A. Vargas remove the trim along the sides of your roof? One body shop insisted on removing this trim as well as the antenna base which made the job very expensive. I don't want any trim or the antenna base removed.

 

[tongsli]

So I know a paint rep who exclusively represents Tnemec paints. They mainly do commercial and industrial projects. I contacted him and this is what he suggested for Carbon Fiber or Fiberglass:

a color tinted (color matched) Epoxy primer with UV stable clear-coat on top. He is suggesting (2) coats of the epoxy primer and 3-4 coats of clear

He stated the color tinted primer will do most of the work to block the UV light from future damaging effects.

 

[808Pants]

I sent A. Vargas Body Shop an email message requesting details of your roof paint job but haven't received a response yet.

Did A. Vargas remove the trim along the sides of your roof? One body shop insisted on removing this trim as well as the antenna base which made the job very expensive. I don't want any trim or the antenna base removed.

Art, hijacking slightly - where ARE the details of how to get those roof-edge panels off? I'm nearing the time when I will have to paint mine DIY and want to be prepared. From the probably-well-known UK video that demonstrates the removal of just about every OTHER outer panel, I suspect it's a piece of cake - but don't want to do it without any "gonna break so have a replacement on hand" clips in my hands.

 

[808Pants]

So I know a paint rep who exclusively represents Tnemec paints. They mainly do commercial and industrial projects. I contacted him and this is what he suggested for Carbon Fiber or Fiberglass:

a color tinted (color matched) Epoxy primer with UV stable clear-coat on top. He is suggesting (2) coats of the epoxy primer and 3-4 coats of clear

He stated the color tinted primer will do most of the work to block the UV light from future damaging effects.

Yes, this is not an exotic thing. CFRP, FRP, concrete, steel, aluminum, whatever: same system works fine, though the clear is always iffy. 20 years ago I sprayed out a test-piece of tempered GLASS with an epoxy primer (glass because it was handy) in order to test the common thinking that a UV-resistant clear sprayed directly over an epoxy would quickly fail in sunlight. (Typical system for automotive pairs a dull base coat with a clear topcoat that's to be sprayed immediately over the base - then as many more clear coats as you like.) It was sitting outside the house in daily UV ever since. Though the epoxy finally began to lose its grip on the glass about five years ago, there was never any clearcoat failure (peeling to reveal the bare epoxy). Problem is that neither of those exact industrial products is available anymore! Similar stuff is, though. Also note that these are "industrial line" products that are always marketed and sold by paint suppliers through different divisions, vs. their "automotive" lines. I'm fairly convinced that the automotive lines just permit a heftier markup with the same formulations, though some are engineered for speed, so that repairs can get out of spray-booths quicker.

 

[alohart]

Art, hijacking slightly - where ARE the details of how to get those roof-edge panels off? I'm nearing the time when I will have to paint mine DIY and want to be prepared. From the probably-well-known UK video that demonstrates the removal of just about every OTHER outer panel, I suspect it's a piece of cake - but don't want to do it without any "gonna break so have a replacement on hand" clips in my hands.

They're attached with clips that usually break when popped out of their sockets, but I'm not familiar with the removal process. I don't plan to have these removed when painting the roof because so many seem to be reinstalled poorly with some even falling off while driving. I don't care if the paint stops where the rubber trim begins along the roof edges. One paint shop mentioned being able to lift the rubber trim to make painting underneath the rubber trim possible. If so, great.

 

[tongsli]

Art, hijacking slightly - where ARE the details of how to get those roof-edge panels off? I'm nearing the time when I will have to paint mine DIY and want to be prepared. From the probably-well-known UK video that demonstrates the removal of just about every OTHER outer panel, I suspect it's a piece of cake - but don't want to do it without any "gonna break so have a replacement on hand" clips in my hands.

You need to remove the rubber trim which covers the channel which has the rectangular slots in the part: A-pillar trim and roof trim. the clip is shaped like an H and has a center stud in the middle which keeps it in place.

The two u shaped clips on the FRONT of the clip holds the aluminum-back support for the rubber trim. The aluminum channel pushes down into the U-shaped clips and the little tab in the center, pinches the aluminum channel in place.

The two tabs in the REAR and single tab on the BOTTOM holds the trim piece to the vehicle. Roof trim or A-pillar

There is a stud in the center which expands the plastic as you push it flush which holds the clip to the Carbon Fibre structure.

Watch this clip I made from a windshield replacement video. The sound you hear is the channel rubbing on those little tabs in the u-shaped clip
https://youtube.com/clip/Ugkxx8tj1E12bY01mwzyHhsosy69PLFbEYFf?si=tJtomobjALKJe8Ud

Here is a clip of him removing the clip from the vehicle
https://youtube.com/clip/UgkxEbfKi85wlRQ68fS9zvYf2JUBXuCf0gom?si=1OYhk9chgyDasHus


The back of the roof trim uses double-sided tape. I think I have some pictures of the clip. Look at eBay for the parts.

 

[tongsli]

So I may be helping a fellow I3 owner who wants to fix his roof finish. When we start the repair, I will make a new post documenting the process. I have offered the use of my garage for the repair.

 

[ksnax]

They're attached with clips that usually break when popped out of their sockets, but I'm not familiar with the removal process. I don't plan to have these removed when painting the roof because so many seem to be reinstalled poorly with some even falling off while driving. I don't care if the paint stops where the rubber trim begins along the roof edges. One paint shop mentioned being able to lift the rubber trim to make painting underneath the rubber trim possible. If so, great.

It's fairly flexible. That's what I did for the vinyl. Tape could likely be used to pull it back enough for other coatings.

 

[808Pants]

You need to remove the rubber trim which covers the channel which has the rectangular slots in the part: A-pillar trim and roof trim. the clip is shaped like an H and has a center stud in the middle which keeps it in place.
View attachment 1273
The two u shaped clips on the FRONT of the clip holds the aluminum-back support for the rubber trim. The aluminum channel pushes down into the U-shaped clips and the little tab in the center, pinches the aluminum channel in place.

The two tabs in the REAR and single tab on the BOTTOM holds the trim piece to the vehicle. Roof trim or A-pillar
View attachment 1274
There is a stud in the center which expands the plastic as you push it flush which holds the clip to the Carbon Fibre structure.

Watch this clip I made from a windshield replacement video. The sound you hear is the channel rubbing on those little tabs in the u-shaped clip
https://youtube.com/clip/Ugkxx8tj1E12bY01mwzyHhsosy69PLFbEYFf?si=tJtomobjALKJe8Ud

Here is a clip of him removing the clip from the vehicle
https://youtube.com/clip/UgkxEbfKi85wlRQ68fS9zvYf2JUBXuCf0gom?si=1OYhk9chgyDasHus


The back of the roof trim uses double-sided tape. I think I have some pictures of the clip. Look at eBay for the parts.

The videos are very useful - worth several thousand words. Once you've got those clips out (or broken) - do the CFRP pieces just lift away with no more drama?

Also without a p/n are these clips still easy to source via ebay, etc? All the same?

 

[tongsli]

The videos are very useful - worth several thousand words. Once you've got those clips out (or broken) - do the CFRP pieces just lift away with no more drama?

Also without a p/n are these clips still easy to source via ebay, etc? All the same?

On the very back of the roof trim, there is double sided tape. I think it's because the C-pillar dives down and they decided not to put in a clip but I'm not sure. I only know some people have reported the very back part next to the rear hatch is loose and they notice double sided tape. I'll post the PN for the clips.

 

[oldbimmerguy]

The traditional way that a rubber gasket or seal is pulled back to allow paint to continue under the demarcation of the rubber and the paint surface is to use cotton cord. A.125 or eighth inch cord is stuffed under the flexible rubber edge so as to hold the rubber up. Then mask. Then when done,a razor knife and care is slowly used to pull the cord out. Cars used to use rubber to seal glass, this way glass not removed but paint is sealed under the rubber. If u simply paint up to the rubber leaving an exposed edge, that will fail.