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Hagerty
Hagerty Employee

Why does fiberglass painting take so long? We peel back the layers

There is a certain smugness that comes with owning a fiberglass-bodied classic car. While others worry about tin worm eating away panels stamped out in the factory or hand-formed on an English wheel, owners of cars made with glass-reinforced plastic (GRP) know that rust simply won't be an issue.
https://www.hagerty.com/media/maintenance-and-tech/why-does-fiberglass-painting-take-so-long-we-peel...
25 REPLIES 25
hyperv6
Racer

Well one thing to keep in mind not all fiberglass is equal. Some panels are gone better than others.

Also now Most panels are sheet molded glass or composite.

Lotus also was not known for fine glass panels. I was in a Europa that would make most kit cars look good.

The worst thing on glass panels and molded panels is the need for large body gaps. These panels can shift and grow on some cars.

Mind will make popping and cracking noise in the sun.
Snailish
Instructor

Google "Corvette Birdcage Rust". 

 

Where fiberglass meets metal is often a problem, in our rust belt area "project" Corvettes with strange body swelling/lines breaking out in odd-looking spots come up from time to time. You don't want to buy that one.

 

hyperv6
Racer

Until the Vette moved to KY most had body defects and paint issues.

 

Materials and production improved there to where it is not an issue anymore.

 

As for Corvette rust there is still more metal in a Corvette C3 vs a Chevette.  Metal just rust no matter what body covers it. Same on the Fiero as under it is all steel and the body is mounted in epoxy mounts. 

DUB6
Specialist

   The hood on my GT-faux (actually a cloned LeMans) is fiberglass (long ago forgot the manufacturer).  Now, hardly any of the sheet metal on the car is really all that straight, but the hood was extremely "wavy".  And, as the first or second most visible area of the car (especially to the driver), it was just too much to bear.  So we sanded.  And we primed, and we filled.  And we sanded again.  And primed again.  And we repeated numerous times.  And still, just when we thought we had it and applied the base color, the storm would come again and the "waves" would appear.  I can't remember for sure, but I think we painted that hood maybe 6 or 8 times.  Possibly more - I think I may have blocked out the memory of it all.

   Metal working on body panels is hard enough.  Doing the same on fiberglass is a WHOLE different animal, and VERY much harder.  It looks okay (well, the whole car barely looks "okay"), so I guess we won the war.  But I'd think twice or thrice before I undertook that again.  🙄

Klharper124
New Driver

Instead of painting it, why don't you wrap it.
Wrapping a fiberglass car seems to make more sense on older fiberglass cars than paint. Particularly a car like the Esprit with its large flat panels.
You don't have to strip the car as the wrap will hide the spider webs, you would have to fix any damage, but that is going to need to be done regardless.
The wrap is going to cost a fraction of a paint job and is going to last about 8 to 10 years, longer if this is a garage queen and rarely taken out.
I wouldn't wrap a metal car, but for an older fiberglass car I think it is a good option.
TonyT
Technician

Bear in mind that the material that the wrap is made of is not very thick and any surface irregularities will still be visible. The article goes into detail about preparing the surface for the topcoat, so proper body prep will yield the best results regardless of that topcoat. And if you've ever had to remove a years-old wrap, you'll wish you were working with metal. That adhesive is a sonuvagun to remove!
DUB6
Specialist

Yes, I was kind of schooled by the local wrap guy who told me that the prep for a good wrap job was almost identical to prep for paint.  On the upper surfaces of my pick-up, where the clear coat has flaked off, I'm considering wrapping, but I told him I'd do it in "camo" so as to not have to worry too much about surface imperfections, they'd just disappear into the pattern.  He frowned at me, and said, "good luck with that".  😋

thebrave
Pit Crew

Good idea, but according to the article you're not even supposed to use car cover on a fiberglass body.  Won't the wrap cause problems too?

daffodildeb
Intermediate Driver

Back in early’70s, I had a ‘69 Saab Sonett V4 (the ugly one). A car rear-ended me in traffic one day, and pushed me into the car ahead. The only part that had to be replaced was a tail light—everything else was fiberglass repair. I took the opportunity to repaint the car in another color, and it turned out perfectly. I had no idea fiberglass repair or painting was so involved! I will point out that today’s Sonett buyer would do well to inspect for rust UNDERNEATH the fiberglass. Apparently it’s an issue in some cars.
Mike_E_V
Detailer

The process sounds very familiar to doing an old-school lacquer paint job but without as much buffing and rubbing.
Fatcat321
Intermediate Driver

I don't find restoring a fiberglass body any more tedious than steel or aluminum. And I have done several of each. Each has it own problems. To properly do a steel or aluminum body, you have to go over them with a dual action orbital sander. Steel and aluminum bodies will be fraught with small dents and dings which have to be attended to, just as you will find cracks and chips in the fiberglass. Chemical paint removers should never be used on any body. Try not to sand through the gelcoat if there is any. If an area needs to be patched, taper the edges around the void back at least an inch, then soak the ground area with MEK to soften the old fiberglass some. Let the MEK evaporate, then glass in the patch. Do the grinding and finish sanding to contour. Then prime with a top quality two-part epoxy primer. Finish sand and paint. I look at fiberglass as an artist's medium. You can do anything with it.


TonyT
Technician

A couple of years ago, we had rented a small hangar at a local airport for a special project vehicle. Right next door was an aircraft refurbishing shop and their specialty was repainting airplanes. They exclusively used chemical paint strippers, and after seeing them strip a Beechcraft KingAir to bare aluminum in two days, we understood why they used that method. It would have taken a couple of weeks to hand-sand that plane and it would have been twice as expensive to do the whole refinishing job. The strippers they used were tailored to the task, and was environmentally friendly with low to no odor, in addition to leaving the surface ready for primer. The various bits of fibreglass (antenna nacelles and other lumps and bumps) also were not damaged by the stripper. Use of chemicals to remove paint is a choice but when doing paint for a living on million dollar airplanes, there's a lesson to be learned.
70amc
New Driver

This is a little bit of a crock. As a former marina owner that has done my share of fiberglass repair it's not that difficult. Actually currently repairing a damaged fiberglass front cap on a a 5th, punctured and fracture cracks. Quite easy Actually. It's the autobody shops that don't have a clue. That said, 25 Yeats ago I sanded a 1980s vette down and gel coated it, it looked great and held up like steel. Most body shops don't know how to spray gel coat, that's the key factor on a major restoration of anything of value.
Conwell
New Driver

I have owned fiberglass cars as well as boats for around 40 years. I find that just like anything else, if you aren’t used to working on it, it’s more difficult the first time.

In the grand scheme of things, fiberglass is easier to work on than metal. There are many good materials that have been used in marine applications that can cross over. The statement in the article that states that fiberglass absorbs water is ridiculous. I’ve had boats in the water floating for many years. Yes, it will absorb water, but only when it’s floating. Most cars don’t float and aren’t stored in the water. I think the writer of this article hasn’t done much fiberglass work. Just ask a guy that works on fiberglass boats all the time which they prefer to work on metal or fiberglass Conversely, ask a metal worker, which they prefer, both will prefer what they are used to working on and have developed skills to work on.

I would also dispute the statements regarding covers. There are boats in Marine applications where the fiberglass parts are covered with waterproof non-breathable covers, and when uncovered, those areas look better than the parts that are uncovered all the time. If there is a problem like the ones described in the article, there has been some misapplication of materials on the fiberglass when it was completed or repaired. Fiberglass isn’t the problem, the people working on it that are used to working on metal are the problem.
wrxelan
Pit Crew

I have several plastic fantastics. ERA Cobra, Lotus Elise, Elan, Esprit, and Europa. The ERA body work was a snap, built like a boat. In many places the skin was over 1/2" thick and as solid as a rock. I'm on my way out to the garage in a few minutes to complete final sanding of the Europa. Not built like a rock, super thin panels everywhere. It's like sanding lasagna.
hyperv6
Racer

This was my experience with the Europa. I was in a JPL Champion edition and found the body panels worse than many kit cars over the years. But it was molded for light weigh and most panels are thin and lack much support.  It may not be a quality issue but more a weight issue know Chapman. 

 

The Corvettes that are restored correctly from the past often will reproduce fiberglass issues where they are know for them. Back in the day they were glued together in St Louis and often seams would be still seen in some areas. Victim of mass production. 

 

The greatest challenge of composite panels like this is door gaps. Even the Saturn with the molded panels had issues with wide gaps as the bodies would move with sun and heat. 

 

The C8 gaps are a testament to the level of panel quality today on these new SMC panels. Same on cars using Carbon fiber. 

carnusse
New Driver

I'm not sure if the comments presented in this article apply to all fiberglass, but my experience has been completely different. I restored my 1963 Corvette Split Window Coupe 25 years ago. I did a body off restoration so I rebuilt everything - engine, transmission, rear end, brakes, suspension. When it came to the body, I stripped it with fiberglass friendly stripper and had no problems. I removed all the gel coat in addition to the paint and primer. I did necessary repairs and worked all the factory gaps of swing metal so they were tight (3.5mm) and flush. I then primed the bare fiberglass with Dupont Corlar Epoxy primer and wet sanded it glass smooth. Then laid on Dupont Chroma Base (Riverside Red - the original color) and Dupont Chroma Clear. Wet sanded that and polished. After 25 years, the paint looks perfect and the car has received many awards. So my experience has been very positive and no more difficult that all the steel cars I have restored and painted.
DUB6
Specialist

I'm sorry, did I miss something?  I was reading this comment and then I got to the words, "1963 Corvette Slit Window Coupe..." and I must have sorta drifted off.  My body was still sitting here at the computer, I guess, but my mind and spirit were out on Route 66 in a red Split Window, rowing through the gears, tooling along with Linda Ronstadt crooning out of the stereo, and an ice cold Coke waiting for me at the next drive-in.  I seem to have been out there for quite some time, 'cause when I came to, it was no longer 1966, and I was sitting in a leather recliner instead of a bucket seat.  Fill me in on what happened while I was gone, willya?  😋

TG
Technician

as far as storage solutions - mine has for years been to drive them regularly (even in winter - weather permitting) and never store a car. My personal beef with car covers is that they are a significant deterrent from driving the car. The fiberglass issue is new to me, but I have seen many cases where dust/debris gets between the cover and the car (particularly when outdoors) and does a nice job of sanding away the finish
hyperv6
Racer

The key to covers is to have the right one for your needs and use. Not all covers are equal.  

 

Also a Cover is not a replacement for a garage either as some like to try to make them. 

 

I cover my car inside but I use a high quality light cover as it is so easy to put on and off and easier to store. Also I have one cut for my car. 

 

Universal covers are a pain and fit poorly. Also if you use a heavy outdoor cover inside it can be a pain as they are bulky. 

Dirt should not be under the cover. If it is you covered a dirty car and that is a major no no. 

 

 

hyperv6
Racer

Look it comes down to knowledge of the person doing the repair and the quality of the panel. 

SMC panel like on the new Vettes are near perfect out of the mold. 

Hand laid glass it depends on the person doing the work. 

My body is SMC with no issues. The hood and rear scoop for my car are hand laid and they needed work. The hood was horrible. Air pocket issues etc. 

 

 

GlidingPast
Pit Crew

On my Lotus Elise, there are certain panels on the car where the GRP looks raised when looking very closely. Those areas are inline with the adhesive bonding material Lotus used to glue the under structures together that make up the body fixings. I guess the saving grace is that they all do that, it's just more obvious on some of the paint colors.
DougL
Detailer

On the brighter side, fiberglass is a lot more forgiving than steel. Some years ago I drove my C4 Corvette to work and my friend drove his Acura. We had a surprise hailstorm. My Corvette was undamaged. His Acura received about $10,000 in damage and was almost totaled.
SAG
Technician

Well let's scare the 'Hell' out of a "composite body" car owner.
Unless they own a "Indy Car" or other high end Race cars_
IMSA, FIA
They think your trying to "rip them a new one".
Their Mechanics "Take them to the BANK" every time they look at it.
Composites:
A Major TOXIC environment, Mechanical Dermentitus & the rest of the fun from solvents.
40 yrs in the Business
Owners: my heart doesn't "weap for you"!!!
SAG
Technician

40 YRS
INDY, IMSA, FIA
Restorations