To continue with my progress:

The underside of the two scoops have been smoothed:

One side required much less filling and sanding than the other but they were not too bad. The finish is not down to 400 grit paper yet as the underside will require some glass work but it's much easier to work on these before they are attached.

I want to maintain the original hood lines as much as possible. I remember reading in Skitime's thread that he had created a recess in the hood surface to accept the mounting flange on the scoop. This would keep the top edge of the flange as close to the original hood surface as possible. I PM'ed Skitime to see what he used to make the recess. Skitime apparently used a circular saw while holding the blade to the right depth. I asked him about using a router but Skitime said that he had difficulty with the bit burning the hood. I didn't fell comfortable with the circular saw idea so in the end I did use a router with a new bit and didn't have any problems with burning. The router is a little difficult to control freehand but it worked quite well, my lines are not quite as strait a Skitime's but they will be covered anyways. Here is a picture from Skitime's thread:

And this is how my hood turned out:


The mounting flanges on my scoops also needed some work as they varied in thickness from about 3/16" to 5/15" in thickness with a few spots that may have been thicker. I ground the bottom side of the flanges down until they were more or less a uniform thickness.

After a test fit, I realized that I would also have to router a groove down the center of the hood:

[This message has been edited by Sourmug (edited 05-08-2007).]

By the way, the hood may not be completely uniform in thickness. I did penetrate in one spot:

It's very easy to do. I also did not make the center groove as deep as the others. Down the center line there is mostly only one layer to the hood and I didn't want to penetrate it which would only make more work when it comes time to clean up the underside.
Here is the bit that I used in the router, I don't think that I will keep it for wood use and fiberglass is extremely hard on cutting blades and edges:

This process of routering the hood produces a TON of dust and airborne fibers, make sure you are wearing the appropriate mask and face shield when doing this.

After cleaning the grooves and the scoop flanges it was time to bond the scoops to the hood. I "buttered" the underside of the flanges as well as the edge of the scoop opening that touches the hood with the panel adhesive:

The scoop was then placed in the grooves, checked for fit and screwed in place with drill point self-tapping screws. These little babies are great when you can't use a clamp:

Here is one side bonded and screwed down:

When the second scoop was buttered, the joint between the two halves was also buttered. Then it was placed and screwed:


When using these screws there will be penetration of the tip through the bottom layer but these will be easily patched and sanded when the bottom is finished.

[This message has been edited by Sourmug (edited 05-08-2007).]

The following morning I removed the screws. I was a little nervous as the two front outside edges of the scoop did not sit down on the hood and had to be bent downwards when I was screwing the scoops on. I was concerned that they would pop at these corners. The scoops appear to be fully bonded with now gaps.

After a quick sanding to get rid of the excess adhesive and a cleaning with acetone I applied the fiber reinforced bondo to fill in the remaining gaps between the flanges and the outside edge of the groove:


This was also sanded afterwards to provide a relatively smooth surface for the layer of fiberglass that is going to be applied.

There is one modification that I want to make to these scoops. The front edges sit too far back from the leading edge of the hood and seem to conflict a bit with the front edges of the lights. I want to extend the leading edge of the scoops forward. I cut two extension pieces from the scrap pieces that were cut out to form the hood openings below the scoops. These were shaped using a belt sander to match the needed contours:

[This message has been edited by Sourmug (edited 05-08-2007).]

Once I was satisfied with the fit, the pieces were then bonede and screwed in place:


They were left over night as well.
The screws were removed and the extensions and the filler were final sanded prior to fiberglassing:


After cleaning the fiberglass has been applied:



And that's my prgress for the weekend.

Nolan

[This message has been edited by Sourmug (edited 05-08-2007).]

[This message has been edited by Sourmug (edited 04-03-2006).]

quote Originally posted by ryan.hess: Question - actual fiberglass, or fiberglass bondo? And, why?

Ryan:

The fiberglass reinforced bondo was used to fill the gap because it has higher strength than regular bondo. I then used fiberglass over the joint as shown in the last pictures to prevent cracking. Does this answer your question or am I confused?

Nolan

[This message has been edited by Sourmug (edited 05-27-2007).]

[This message has been edited by ryan.hess (edited 04-03-2006).]

quote Originally posted by ryan.hess: I don't know: What's being used in this pic here? Did you use fiberglass bondo, and just stuck some fiberglass mat into the mix, or did you fiberglass bondo it, wait, then apply fiberglass with resin over it? I'm just confused as to why you did it the way you did... Isn't the bondo enough? Or... why didn't you use just fiberglass w/resin?

The picture that you posted is when I applied the fiberglass mat and resin. It is my understanding that there is a risk when using just bondo on a joint that, if there are any stresses involved, cracking at the joint may occur. The hood is subject to stress when it is being opened and when it is being closed, especially if allowed to slam shut. Also in this picture:

you can see that under the duct tape the leading outside corners of the scoops are elevated off of the hood due to the scoops not completely matching the curve of the hood. These corners had to be pressed down when the scoops were attached and this also induces stress.

The reinforced bondo was used because when I removed material to make the groove for the flanges it would weaken the hood surface. My grooves did not perfectly match the outside edge of the flange and so I wanted to add some reinforcement back into the remaining gap. It also smoothed out the groove so that the fiberglass would go on relatively smooth.

Is it overkill? I don't know, but why take chances?

Nolan

Edit to add this picture which shows how the corners didn't sit down on the hood:

[This message has been edited by Sourmug (edited 05-27-2007).]