I posted this last week in the body forum but got no respnses so i thought i would post it here.

I need some tips on attaching a fiberglass cowl induction hood scoop (non func.) to a steel hood. My idea is to rivet the flange on the hood scoop down to the hood then fiberglass around the edges to make it appear part of the hood. I'm usually a bondo kind of guy so i need some tips on glassing this thing on.

Should i just use resin around the edges or should i put matting as well? How well does the glass stick to the hood? Can i just throw it on or does it need some kind of anchor? Does it need bare metal or can i put it over the paint? The hood supports underneath are cut in a few places so the hood flexes a bit. Do i have to worry about my fiberglass cracking? Any other tips?

They only rivets i have used are pop rivets for sheetmetal. They don't have much surface area under the head so i am worried about the fiberglass pulling through and launching through the windshield at high speed Are there rivets that have large flat heads like a carriage bolt??

-Jon

 

Hey,
you can get rivets in all types of designs . i use some that have a head a bit larger then a dime . i also use some that are molly rivets.
but . the rivets aren't all that important . you basicly are just using them to hold the scoop in place while your glassing it .
yes sand to undercoating at least . rivet scoop in place . cut glass matt in 4" wide strips and about 12" long . you want to overlap them and cut as needed to go around the permeter of the scoop . grind/sand on the scoops flange also for good adhesion .
i would suggest a piece of cardboard about 12" wide and 24" long . mix your resin , usin a disposable paint brush pour some resin on the cardboard and spead out in an area slightly larger then the glass matt . place glass matt on card board and then pour some resin on matt and brash out to make matt "clear" looking . (no white will be showing) this will make sure the glass matt is throughly saturated with resin . (please use rubber gloves) take soaked glass matt off cardboard and lay over edges of scoop ( 1/2 on scoop,1/2 on hood ) after matt/resin has set up you can come back and grind on it to smooth it out and add filler to blend with hood . good luck

 

Well I can't realy help you about how to put it on but I built my baja bug a few years back and I had a lot of trial and errors with fiberglass(hood, fenders, visor..ect), I'd suggest drilling holes in the fiberglass first before putting rivets in it...Or maybe even masking tape all around the holes that will be made because the fiberglass chips easily.

 

Thanks guys, i will let you know how it goes. I on my way to pick up supplies right now.

-Jon

 

I got the scoop all riveted on. I put rivets all the around every 5" or so to hold it since i will need to drive the truck before it gets glassed in. Turned out great, looks good already. I also used a bead of rtv under the edges to keep the wind from whistling underneath. I think nex wednesday i will try my hand at fiberglassing if the weathers nice.

-Jon

 

I'd like to see some pics if you get around to it.

Thanks,
Justin

 

sprocket

FYI to anyone doing fiberglass work/add ons . as sprocket suggested pre drilling . always predrill holes for rivets (in most cases ya got to ,...lol) but when you start the hole . run the drill in reverse to prevent chipping of the glass/gelcoat . til you get through the gelcoat then run in forward to drill your holes . makes it alot easier to keep from chipping the gelcoat .

this is also useful when drilling through carpet . run the drill in reverse to keep it from wrapping up on the bit . (or on any fabric for that matter )

 

ya what he said...

 

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