AAR fiberglass hood issues ...

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rebeldart

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Finally bolted it on tonight to test fit (already painted, drilled for dual scoops, had it for a year). Bolt - on hood using lightweight springs. It fits fine around perimeter, sits flush on all four corners but - bowed above fender on both sides nearly a half inch, also bowed across cowl. This looks bad - I'm hoping after final assembly I may be able to place weights in the areas and matbe it'll lay down ? I know I shouldn't expect a fit like a metal hood, and they're more for race than show, but I ain't happy cosidering what it cost. Will weighting it down do the trick over time ?
 
Let it settle a few days. Get some heat in it from the top and bottom. Your light springs still might be bowing the sides.

Bob
 
I'll be taking back off this week, I'll try weighting it down a day or two in the sun and see if it'll relieve the bows. I don't think the spring pressure's doing it considering the reinforcements/ribs this thing has. I just think the curvature is off, period.
 
wouldn't leave it too long with weights on it in the sun. why not leave it on so you can see any changes from the weights.
 
I have heard that even the factory AAR hoods never laid down perfectly like steel hoods.
 
You're right in that...........

An AAR hood never sat down flat..........they were always bowed about a quarter inch or so on the sides...........

When these fiberglass hoods lay around for periods of time (not on the car), they can tend to bow a little also.........usually when they're leaning on something.......and if the pressure is not even, the bow can be slightly asymmetrical in appearance.

Your weights might help if enough heat gets into the hood, but the chances are good from what you say that the hood has been incorrectly molded. I've had some problems like this in the past........if it's out by a half inch, and 3 sides are incorrect, chances are that you received an incorrect hood.
 
Been researching glass hoods for a while and it seems heat is not really good for them on or off the car. Also if you had it stored on its side for a year, especially in a hot garage or something, that can warp it pretty good. I'd put it on and leave it there a while.

If I get one I want it right off the presses so its not lying around in a warehouse for a long time, then test fit right away.
 
Naw brother Tom - it's the right hood ... http://www.aarqualityfiberglass.com/cart/product_info.php?cPath=26_27&products_id=174
Picked it up myself down in Cocoa - I'd talk to AAR if I thought it would do any good, but since I've had it over a year and already painted, drilled for scoops and all, I doubt they would help (as in another hood). So I'll try the weight thing and hope for some results. Won't be noticeable at shows/cruises 'cause the hood will be up, but it's very obvious when closed. I may show it to them at Garlit's show (if the car is done by then).
 
I didn't mean an incorrect model.........I meant an incorrect molding.......

AAR is a company we've gotten many pieces from, and the quality is generally good.....BUT, the process, especially when the actual "mold" is on it's last legs (they don't last forever), is not perfect.

My statement about AAR hoods never being flat refers to the AAR Cuda hoods, not AAR Fiberglass Co.........that was just the nature of the beast........they always had a 1/4" or better inverted "ski" to them...........Sometimes a trailer frame will be welded with a "ski" in it to compensate for weight factors when constructed.........If the AAR Co. uses this theory for your particular hood, it could have the bows in it directly out of the box, BUT it doesn't seem that it would be a half-inch........That's nasty.

I received a gull-wing door once for a custom van conversion that was SO out of level, it was actually 1" concave dead center.........That door was removed from the mold too soon, and I got stuck with it due to the massive freight charges...........

I hope you can do better with the hood...........Maybe it will settle with some weight and heat........just be careful not to overdo it........ Good Luck. 8)
 
rebeldart said:
Naw brother Tom - it's the right hood ... http://www.aarqualityfiberglass.com/cart/product_info.php?cPath=26_27&products_id=174
Picked it up myself down in Cocoa - I'd talk to AAR if I thought it would do any good, but since I've had it over a year and already painted, drilled for scoops and all, I doubt they would help (as in another hood). So I'll try the weight thing and hope for some results. Won't be noticeable at shows/cruises 'cause the hood will be up, but it's very obvious when closed. I may show it to them at Garlit's show (if the car is done by then).
Click to expand...
They may not take it back, but they could probably offer advice as to how to flatten it out.
 
I would remove the spring and see if that help it. It would be worth a shot, some of the light weight springs are still to strong and cause the hood to bow up in front of the hood hinges.
 
Hi Guy's

The glass hood on my Duster stay up and required practically no force to close it. I used hinge spring from a late '90 Dodge shadow and shorten them 3" if it help somebody.

Robert
 
Pastortom is correct. The AAR/T/A hoods would (after time) start to bow up because the metal bracing for the hinges didn't run far enough forward. The repops of those hoods have longer braces in them to prevent that. I was lucky in that the original T/A hood I used on my Challenger had very little bow to it.

What they used to do in the old days to flatten these was park the car in the sun, and then set a toolbox on each side of the hood to flatten it out. Yeah, I know it sounds ridiculous,, but that's the way it was done.

Next bit of trivia? You know what works best for keeping the Organosol paint looking beauty?

Lemon Pledge

039.jpg
 
same problem with my hood, not that bad but all 4 corners fit good, middle is bowed around 3/8 inch. I am going to try the heat trick, not sure I think my body guy talked to them and they said it should settle some, But it is still off by over a 1/4 inch. So, it did settle some!
 
how does "flattening" the hood with the sun and toolboxes treat the paint you just put on? Does it crack it or doesn't seem to bother?
 
Most folks know that (production) fiberglass parts come from a mold.
Production parts are rarely hand laminated, they are made with a "chopper gun" that spits out glass fibers and resin at same time. This is perfectly ok for parts that don't require super high strength, but this method tends to be "resin rich". With hand laminating, you're able to regulate the resin content more closely.
The reason this is relevant is because resin builds heat when it cures. The higher the resin content, the higher the heat build up. When you are in a production environment, you're expected to make parts fairly fast, requiring that you mix your resin batches fairly hot (more catalyst) to harden faster. Also, I'm betting that the parts aren't staying in the molds for full cure time, which is a full 24 hrs. If the parts are pulled before curing (cooling down) they warp, guaranteed.
Further more, without REALLY good framework on the mold, IT will eventually start to warp from the cyles of heating/cooling over time.

Sadly, once those stringers (braces) are glassed to the underside of hood, thats it, she no move, bend, or sag. Don't believe? go look at a AAR Cuda or TA Challenger with original hood. Almost 40 and still bowed, right? Cutting the braces, re-stressing and re-glassing would help alot, but thats not for the faint of heart .

Hope this sheds some light on a dark subject.
aloha-pauly
 
Thanks Pauly - I used to work at a diving board plant and recall much of the processes you described. The hood is built well - reinforcements are partly steel (see my link to the item above) , I'll try the weight but have my doubts. I may call AAR tomorrow and see what they say (probably "give it time to settle").
 
Yeah, I was talking about the AAR 'Cuda hoods from 1970, which were the first factory fiberglass hoods I remember. I don't know of the quality of modern day hoods, but I am sure interested in them because I would like to ameliorate some of the extra big block weight on the front of my car.
 
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