I have read all the post on bonding fibergl*** scoops to steel hoods and it seems the bottom line is sooner or later the fibergl*** to steel bond will break due to different rate of thermal expansion between metal and fibergl***. So is the best way to have professional clean look to use fasteners bonded into the scoop (internal flange) and bolt it on to the hood? If the scoop is trimed correctly the seam between hood and scoop should be very small - maybe a flexible caulk but paintable would work better there - any thoughts?
If this is going on a race car, you might be better off making the scoop removable, maybe attatching it with DZUS fastners. A clean install that way might end up looking better than trying to mould it in and dealing with cracks in the paint. If this is for a street/show car then I probably wouldn't do that but I can't imagine why anyone would want a fibergl*** hood scoop moulded onto a street car.
molding a gl*** scoop on a steel hood is asking for a failure,, there will be some that say that is it possible and will last a long time, but I dont recommend it. Flange and bolts are the way to go, use black closed cell foam to make a gasket. If it is for a race car dzus it on,, use the nice cad plated brackets, and bolt them on,, poop rivets **** and will loosen up very quickly, use some small edge guard to cover bottom edge and your done. Also use STEEL rivets to hold the springs on, and its a good idea to get some that are a little too long so the spring stays on longer
i had a 70 nova with a steel hood and a fibergl*** cowl induction scoop. the scoop was pop riveted to the hood, and fibergl*** was covering the pop rivits and the guy molded the edges of the scoop to the steel hood. it looked like a factory cowl induction hood.( i bought the car this way). eventually, the fibergl*** cracked all the way around the scoop. this was not the best way to mold a scoop to the hood in my opinion. it looked ok for awhile, but eventually it cracked. the bad part was that the car had really nice paint, but the hood scoop had this big crack all the way around it that stuck out like a sore thumb. i ended up yanking off the steel hood and putting on aone peice fibergl*** cowl induction hood. i needed the clearance under the hood for the air cleaner to fit, or i would have just put a stock flat hood back on it.
Had one of those 427 ford hood blisters with the 2 screens at the back. mounted it to my '57 fairlane using 1/8 taperheaded screws 1or 2 inches apart. sanded hood on mating surface to bare metal, preped the fibergl*** same way, and if I remember correctly, (this was 1969) I used Dev con or one of them epoxys between the two and with my buddy we scintched her down tight. In a few minutes we feathered the edges of the gl***, grabbed some ol' Blue Moon Bondo and waa laa!!!! Now this had a econoline axle up front, and I lived out on the farm, and the ruts in the driveway where huge, so you can imagine what kind of abuse that car took from a 19 year old. After 2 years sold it, and it still looked Great.......Maybe just luck? My 2 cents, OLY The cancer car lives Give to cancer research
So as I thought, the only way to secure fibergl*** to metal is with fasteners. My only debate is what to sandwitch between the two: adhesive, foam/rubber, caulk or just nothing! Just don't know which will make the less visable seam.
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