cockroaches and fiberglass

I'm looking at a restored '78 IM speedster. My question to this forum is; What is the life expectancy of the fiberglass? Can it last forever, or does it deteriorate over time. Please feel free to offer any advice or comments. George?

The good thing about buying at this age/stage is any problems
that were "built in" should have shown themselves already or now.
Such as sagging, cracking, flexing, soft spots, layer separtion
etc. Think of the good side, no rust or dents.

I have read information from body repair guys that fiberglass does slowly change, but these changes are very slow and like the other response said ....you do get the advantage of looking at the product and any problems should show themselves. Even a 78 fiberglass product is much better then the 50's and 60's when fiberglass manufacturers didn't really know the problems that needed to be addressed by using fiberglass as the body. If you do see problems such as listed in the previous reply the car should be looked at by a body shop to give yourself piece of mind. Look for a body shop that is doing a lot of fiberglass repair and restoration as they are more experienced in giving quotes for proper repair.

Since I own a 78 IM I thought I would add my two cents beyond the fiberglass body issue. I figured I would buy a fixer-upper, see if I liked owning such a small car and perhaps buy a later model or new Speedster.

What I learned is unless someone has already replaced the bolt-on parts, the front steering and suspension pieces, under coated the bottom of the pan, new top and side curtains, etc., etc., you can expect to drop a good amount of money into your car in no time. Ask me how I know. And if you aren't handy yourself you will be paying someone else to do the work and that REALLY adds up.

My thinking has evolved. I feel like it may be more cost-effective to be patient and buy a later model Speedster in like-new shape and just drive and enjoy it rather than refurbish one that is long in the tooth. Of course if you like messing with cars, I do somedays, the process is fairly enjoyable and the end result will be done your way.

It will depend to a large degree on the type of resin used, the catalyst-to-resin ratio used, and the resin-to-glass ratio; the glass fibers themselves should last indefinitely.

Newer cars use better formulated isothalic resins that are less prone to moisture absorbtion and remain more flexible. Some fiberglass companies also test resins and catalysts before use to insure quality.

The boating and aircraft industries have led the fiberglass quality quest, and vinylester resins seem to be one of the best for the money. Epoxy resins are stronger but usually more brittle. Any stressed fiberglass laminates require molded-in reinforcement or backup plates or cracks will probably appear.

I would think the life of a modern fiberglass component in a normal environment (no unreasonable stresses and temperatures between 10 and 120 degrees F) would be almost indefinite.

IMO, George makes a good point about the comparison to fiberglass boats - at any marina you can see fiberglass boats manufactured as far back as the 60's that are still floating and in good condition - even with constant exposure to weather and sun. I think the things to watch for are stress cracks and possible water intrusion in screw holes or unsealed edges (water could conceivably penetrate inner layer beneath the gelcoat, resulting in delamination problem). Fiberglass is very repairable if potential problems arent ignored. Think of all the old fiberglass Corvettes still rolling around too. The prospective lifespan of the Speedster body is something I feel pretty confident about.

Terry: If it is a 'restored' 78 IM, then most of the issues Erik mentions should have been addressed. The fibreglass body should be fine. I just sold a 78 IM (mind you, it was not assembled until 2000 or something), but the body was in perfect condition. I would be more concerned with the mechanical aspects, etc.

RJC

Yep, if the car is sold as being restored/refurbished that is different than buying a fixer upper, though I bought mine from a Mercedes dealership mechanic who said mine was in super shape, right. Have a pro check out the car to be, wish I had of, or that I had a cousin named Vinnie that would pay the seller a visit.

Thanks for the responses. The car has been totally restored by a member here and I believe everything on the car has been addressed, but a decision like this needs some input. The speedster is local and I hope to take a look next week. Thanks so much for your collective input.
Terry

I have to agree with Erik. If you buy an older model, the odds are you will put a fair amount of money into it. Like Erik, I know from experience. On the plus side, I know what's in my car because I put it there.
Ron

Here's something else to consider (from a guy who bought a turn-key)- an older body will doubtlessly be done shrinking. I know IM "cures" their bodies in an oven, but everybody else (that I know of) doesn't. It's not a huge deal, but flawless paint on a turn-key will eventually "ripple" slightly as it cures. Of course, an older body, improperly stored will have sagged, cracked, etc. The guys who take a long time building their own cars usually have the inadvertent advantage of a longer "cure" time on the fiberglass- and as a result, the opportunity for better paint.

Hey ! Don't we all "shrink" with age ? Couldn't resist!

ALan M