[project66]

ok, time for the hood now. Got the fenders and the doors done. I have a stock metal reproduction hood that i stripped to bare metal. I am going to be welding a cowl induction scoop on to it, bare metal also. The scoop has about a half inch flange all the way around, that lays flat on the hood, overlapping it. The company that makes the scoop says the scoop can attached with fusor adhesive or be welded. The question i have is should i drill holes in the flange and spot weld the scoop to the hood or should i try and weld the entire flange to the hood?. When im done i will use filler so the scoop looks like it is part of the hood, like a real cowl induction hood. Keep in mind the scoop goes the full length of the hood from front to back, so welding it solid would be a lot of welding. Its 19 guage like the hood so i would have to weld short welds to keep it from warping.
So solid weld or spot (plug) weld it, then apply filer?
thanks in advance

[pro70z28]

Originally posted by project66

I would spot weld it. Use some seam sealer from an auto body supply to keep moisture out. Spot welding works for factory seams. I would be concerned about a solid weld stress cracking. Then there's the warp factory you mentioned. Just my 2¢.

[scholman]

project66,

I would epoxy the hood and scoop together. No heat to worry about and you can still use filler to blend the seams. The resins that are out now are great. At least give them a look.

Scholman

[troy-curt]

By the time you weld it, fill it and get all the warp out of it, you could buy two hoods that already have the scoop.

Troy

[project66]

By the time you weld it, fill it and get all the warp out of it, you could buy two hoods that already have the scoop. by troy

probally true, but i cant find a metal hood with a cowl scoop, and the fiberglass ones i have not found one that i like the way it fits or looks. The hood i have now fits really well, and i have already bought the scoop. Time i got plenty off, convincing the wife i need another 500$ hood i dont think will happen.

here is where i got the scoop from so you can get a better idea
steel scoop

[troy-curt]

The hood is the most limber part of a car. The minute you touch the hood with a torch it will start warping. It will take a very experienced welder of auto sheet metal to weld a scoop on.

Keep us posted on how it goes. Good Luck

Troy

[pro70z28]

If you can spot weld the scoop on first, then cut the hood opening with a nibbler that will help some to keep the hood straight. Take you time spot welding, pack the area with wet towels to keep heat to a minimum. If you have one available a TIG welder has a more pinpoint weld and should keep the surrounding metal a little cooler. If your not experienced at welding troy-curt is right, it might pay to take it to a body shop.


Drill holes through the scoop flange where spot welds will be made.
Set the scoop in place and drill a few of the holes through the hood to pop rivet the scoop in place and hold it secure.
Pocket weld the holes. Go slow. Keep it cool as possible.
Grind the rivet heads off and weld those holes shut.
Forgot to add you want seam sealer between the scoop and hood to prevent moisture getting to the paint from the back side. Seam sealer is designed to be compatible with welding.
Cut the scoop opening through the hood with an air nibbler.

One thing in your favor, the hood scoop will help stiffen the hood as you weld it on and the rivets will help too. The downside is if you DO get a warp the hood scoop will make it more difficult to get the warp out.

That epoxy idea might be worth a look too.

[BarryK]

Troy hit this on the head with the welding problem.
The best way for any hood scoop, if you want it to last is.

Bond it on with any brand two part metal bonding adhesive.
After placing the scoop in place any adhesive that oozes out take a rag and wipe off back to seam.
Let set over night, with a surface blending disc or 80 grit DA sand off any remainder adhesive that shows.
Prep area and the most important thing you will do next is spray a coat of epoxy before you do any filling.
Here is why. You now have two different metals that are going to expand at a different rate, if you put filler or glass into the equation you have three plus glass does not like to stick to metal long term.
With the epoxy as a barrier coat between the metal and filler work it will make the filler or glass more flexible so you do not get blistering of paint down the road. In other words it will allow the glass or filler to keep up with the expansion.
A this point a thin coat of chopped fiberglass such as kitty hair, Duraglass, Dynaglass and a thin coat of filler over that should taper it all in.