Weld-On Hood Scoops

[Dudewith4x4]

Ive seen a few people do this in their build threads. I was just wondering how hard this is to do and what all it requires? Could you take a hood scoop like that one in the picture and glue it on? Or does it need to be welded or fiberglassed? Any help would be much aprecaited!

[bad6772]

Heat will be the biggest issue and patience when doing these scoops....I would recommend but welding a scoop...Instead of an over lap type weld...or even an lap over type glued panel.....Fiber glassing it in...Will not hold...Things where done like that years ago...But its totally not the best way.....Watch your heat and take your time welding this..Its about the best way IMO.......

[Dudewith4x4]

Thanks man. So I should weld the lip by spot welding and letting it cool and then grind the welds down and bondo over it? The only MIG I have access to is a Flux wire mig. Will this work?

[69BBsuburban]

It would work just fine spot welding it in, slowly, taking yer time...problem is...the hoods on '73-87 trucks are so large and flat, that the vibration and flexing the hood sees will most likely start cracking the filler and paint along the seams....
I've also seen a hole cut large enough to install scoop from bottom, and lap welded in...this creates a stronger flange and will be less likely to crack paint along joint. Guys will say to butt weld everything, but in reality most panels/floors/etc are flanged from factory and when done properly you will have no issues...

Unless ya find a good metalman who can hammer weld it and metal finish it.
There is also a hood made with that scoop already on it...

[bad6772]

I would seriously doubt that by stitch welding the whole piece it would become brittle enough to crack out....If done properly little to no filler will be needed...Now I will agree that in this situation that an over lap weld would be the stronger on the two...Simply for gauge thickness of the hood ...And the amount it will be stressed,as far as opening and closing...But there are very few applications where I would agree with this..One thing to also consider is corrosion ...Doing an over lap is more apt to have corrosion issues than any buttweld...So make sure you use a good weld through primer and a good epoxy....I butt weld 99% of everything and have for years... never had any issues with any stress related cracks..And if filler is applied that thick...It was most likely over worked and I would assume...The metal was warped....at the same time....I have learned to metal finish almost all my butt weld....But for the most part I file my welds instead of grinding...Adding that much extra heat from a grinding disc only makes the weld weaker...Not that I file every weld.But in this application....I would vixen file and work the steel versus mudd....But as 69BBsuburban suggested a lap weld is fine.And probably a better repair in this application.......One thing to also consider...Is going away from flux core and start using gas...There will be less heat involved and better penetration with gas...Either will work..........just saying......Good Luck and be sure to show us your progress.......

[Dudewith4x4]

Well all I have is flux core and its my gramps. Well if I braced the bottom would that stop it from cracking?

[69BBsuburban]

Originally Posted by Dudewith4x4

Well all I have is flux core and its my gramps. Well if I braced the bottom would that stop it from cracking?

Personally, I doubt it.....cause it sounds like this is your first time with something like this and there will be some filler involved. Watch the top of yer hood as ya drive down the road...see it "vibrating"?
That "resonation" will crack out the filler...but not the weld itself per say.
It's one thing to weld in the panel with gas or TIG and metal finish it and another to tack in with a MIG and use alot of filler to smooth things out....

I would seriously doubt that by stitch welding the whole piece it would become brittle enough to crack out....

The filler cracking....not the weld itself....and the filler will most likely start cracking along the edge of the weld, where the vibration of a large, flat sheet of metal, will migrate across hood and stop at the weld seem of the scoop.
I agree with ya though...that if properly done..there shouldn't be an issue.

[chris mc bride]

IMO and Im by no means a body man.The lap weld will be best because it sounds like you have limited experiance with a welder.I will just be easier & I agree stornger.A butt weld should work fine but it will take a better welder to weldit w/o blowing thru and havine to fill the holes.Like I said it just my opion,not body man but been welding fuel tanks for custom bikes for years and if theres a good teacher its the super thin metal used on tanks.