Actually, there's adhesive EVERYWHERE! Once the panels are in place and all the Clecos are in, I go back, pull them one at a time, run a bit of welding rod through the hole to remove as much adhesive as I can, rinse the Cleco in acetone and wipe it down to be sure it's as clean as possible, then reinstall it.

Then, once everything is cured, I redrill the holes to remove any excess. The holes are currently 1/8". The structural rivets need a bit larger hole so once the chassis is blasted and primer/sealed, I'll drill the holes to the final size, then install the rivets.

Can a firewall be art? Yes, yes it can. Nice work, Chris!!

Great work as always Chris. The bonding os such a great idea.

So much cleaner than welding!

Remind me how your planning to finish the firewall? Paint only then the pretty pretty rivets?

Just amazing work. This is an epic build.

@Andyrew - Going with the new main panels means I can "just" paint/rivet. But the stamped recesses are the same depth as those in the earlier open panels. Meaning I can still bond in the carbon fiber, though it'd be for looks only. I still have open panels on the dog house cover that still require the carbon inserts.

I had some scrap carbon fiber so thought I'd see how I could do trimming it to fit the recesses. I figured I could use the male component of the stamping die as a template.

I clamped the carbon to the die, trimmed it then used 80 grit sanding pad on an angle grinder to take it to the final size. That worked like a charm and took like 20 seconds!

This piece is about 2X thicker than I'd use so the "real" piece will sit better in the recess.

But a successful proof of concept, so I know I'm good to go on the dog house cover, and these main panels, should I opt to go this way.

One thing to remember is to cut and finish each piece of carbon so the weave sits at the same angle across all the pieces and looks like the metal was placed over a single piece. Shouldn't be hard to do, I just need to remember and do it!

Looks good as always.

Riveting all the holes in the firewall, I do not envy you.

Pardon me, my car and I are having a bonding moment...

Just an example of how much adhesive there is to deal with in terms of the Clecos. Here you can see the "next hole" is cleaned but the following one isn't.

And note that as you add the next Cleco, the panels pull together and the adhesive spooges out, which is what the directions say you're looking for, so that's a good thing.

Plus, you end up having to recheck and reclean the previous couple Clecos. Fun all around!

Only other person that says "Spooge"

That looks good! Also should provide some sound deadening, I would assume you would use the same panel bonding stuff, which would give it the needed flex.

I cant wait!!! Im guessing were only a couple months away to seeing the car in primer/paint?

Thanks @Andyrew - I'm hoping things will happen that quickly. I need to finish ALL the fab work, which now looks like it's going to include a fixed roof. Hello @914forme !

I'm leaning toward a sheet metal/tubing frame and bonding on a carbon skin. I'm starting on the frame today to see if I can come up with something that will work.

I'm sure you're getting tired of seeing this fire wall stuff so let's call this the final one, because... it's done!

Presenting one custom fire wall, ready for the paint shop!

It's a Beauty Clark

HOORAY! Looks really good!

Was worth the effort!

John

it also hides one out of character feature.........................a sqaure corner....I know you are testing us

Hey now, @sixnotfour , you'll have to talk to @ChrisFoley about that!
I just bought the thing and installed it!

Thanks for the compliments, everyone. It certainly was a looooooooong time coming so my thanks to y'all for your patience while I worked through all that!

And now on to the next little project: a fixed roof!

I want to try building a steel frame and bonding on a carbon fiber skin. I want it to look stock, as though it could be removed, not like the 916 with the drip rails and being obviously fully integrated with the windshield frame.

So... today I started on two of the components: the mold for the skin and what I'm calling the window seal rails.

First the mold. Since I want it to look stock, I can use a stock top to make the mold. I plan to paint the roof (probably black) so I don't need to have everything all perfect with the mold.

I had a smoothed top and I hit it with 1500 wet sand, just to tidy it up a bit.

Once it was all dry, it's time for a few coats of mold release wax.

Once that's done, on goes a layer of PVA. Some folks spray this on but I've had just fine results wiping it on with a paper towel. I pour a bunch on and wipe it evenly over the entire surface.

Essentially, the PVA forms a very thin layer that prevents the layup from actually touching the part.

The only really critical part is that you don't touch it once it starts to dry, else you can peel it off.

Here's the top waxed and with the PVA dried. Shiny is what you want as this is what will determine the finish of the inside of the mold.
Again, not that critical for my project since the skin will end up being painted but the better things are at this point, the better the part that comes out of the mold.

And with the first layers of fiberglass. I use a really lightweight cloth for the first couple layers as it drapes more easily and better conforms to any of the fiddly compound shaped areas, like the front corner of the drip channel.

The other component I started on was the driver side window seal rail. I cut and bent up a length of 18ga and went to work with the stretcher.
Stretch, stretch, compare to the edge of the top, oops, too much. Shrink, shrink, compare again... you know the drill.

About 387 trips between the stretcher and the car later and I'm almost there!

Yes, I know I have to add material to the top of the targa bar to account for the dimension of the seals and other roof elements.

My plan is to get a set of window seals attached to these rails then position the assembly so the seals are in the correct location. Once that's done, I weld in the rails. I'll lay up the roof skin and once I have that, I can locate it on the car then "just" connect things together.

Wish me luck!

Your skills, ingenuity, and dedication never ceases to amaze me Chris

Such a cool project!

Amen brother.

Working away on the window seal rails. Back and forth to the shrinker/stretcher and comparing to the targa top. The surfaces where the seals mount need to be level with each other. This is a good thing in that when I need to position the rails for install, I can simply clamp them to a couple of square tubes that span the width of the car and I'm guaranteed they'll be aligned.

Here's the "splash mold" for the roof skin, getting a bit of solar cure! You can see through it because it's only a few layers thick in most places. You can see I added a few pieces of core mat and layed up over some bent sheet metal to help stiffen things up.

This mold is only going to be used once and the part I'm making needn't be perfect so I did this about as quick and dirty as I could. If it turns out I need a higher quality mold, it's easy enough to make another.

@sixnotfour - Yes! Like that! Except I'm going to build my X brace to be welded directly to the windshield header and the targa bar.

One for @Andyrew : The curvy template tool put to use, once again!

Rough measurements suggest this amount of roll suits the entire X brace; both the "side bars" that tie the targa bar to the windshield, as well as the X brace.

In my design, the skin is really only serving to close things up.

Love that tool

Is the bar design going to protrude into the "helmet" space at all?

@Andyrew - No. Well, let's say "not hardly much." The curve will keep the tubing (1.25" DOM) tucked right up against the roof. Kinda like in the pic @sixnotfour previously posted. But my X will go from corner to corner, unless test sitting and fitting show an issue.

Rough fitting the first side rail bar. At the front, I'll make two small plates - one for each side of the tube that welds to the upper and lower lips of the windshield frame and then to the tube.

I still have some trimming/fitting of the notch at the rear to be sure the tube fits under the roof skin.

that is crazy cool.

Oooh that's sexy.....

Hmm....wrong thread.

That 914 will go down the road like a solid billet of aluminum. That car is going to be wicked fun.

I like the solution for the roof structure. The bars going corner to corner can become a bit of a head banger. Suggestion would be shallow channel and maybe lots of dimple dies. Or stamped panel that follows the theme of the firewall with exposed carbon sections.

Factory GT lids just had a small raised section. I did one of these once, bonded the top to a metal cross section and DOM sides rails like you have. I found that the top got really heavy really quick, and I ditched it. Started thinking steel skin - thus the 944 section and manual latches for the sun roof. Proven design, and could be opened to vent the car during runs.

BTW, I have that roof section and great 944 manual sunroof if you need it. Also have a Ford GT 3rd brake light that needs a good home whilst you're cutting.

@914forme - Thanks for sharing your experiences with roof mods! Sacrilegious though it may be, weight isn't my primary concern. And you know me - I'll likely change the design as I go.
I was noodling on the cross braces, too. I have an idea I think you'll like! More as I get to cutting some material.
And thanks for the reminder about a 3rd brake light! I'd overlooked that completely!
I'll PM you on the GT light. I have a part I think you may want to swap for it...

Change of plan #1: I've decided to bond on a gutted stock roof. This solution comes complete with seal rails already in the correct spot and a virtual guarantee that it'll look stock to all but the most attentive observers.
Plus it saves me time fabbing the roof skin.

I'm running early doors so I went with an early roof as I understand mismatching early/late doors and roofs = issues with the window-to-roof seals.

I'm curious in that, near as I can tell from places like 914 Rubber, the available replacement seals are all "late style". Is it the shape of the seal channel or something?
Anyone know the details on this?

But for now: I thought our roofs were fiberglass. I didn't know they had a core in the header! This is my "learn something new everyday" item for today.

Anyway, here I've clearanced the header for the side bars. I'll add a couple layers of fiberglass over these areas.

I also quickly realized that running the stock roof meant I'd need to move the side bars inward a bit to clear the inner portion of the roof. So I did that and ended up with what I think is a nice fit.

The side bars sit up in the roof such that there's no head/helmet issue at all.

One impact of this design approach is that without the windshield-to-roof seal, the roof is able to slide forward about 1/4". This is the "attentive observer" item mentioned earlier.

I used some ratchet straps to help hold the roof in it's new forward location. As mentioned, I plan to paint the roof black so this is sorta what it'll look like once it's bonded on.

I plan to seal the joint but leave this area looking as much like this as possible. I won't try and fill that joint but rather leverage the bonding adhesive and perhaps a tiny amount of sealer to prevent leaking. Ideally, the roof will still look as though it can be removed.

It's a bit hard to see but one other area that will need a bit of fab is across the rear of the targa bar to the roof. With the seal that normally fits there now gone, there's a gap. I'll create a piece that welds to the targa bar and has some sort of flange to which the roof will bond.

On to the X-braces!

In looking at that last pic, I realized I'm only a couple days away from permanently removing the door braces! Boy, oh boy, talk about a MAJOR milestone...

Initial fitting of the outer rail-to-windshield plates. Both sides are tacked in, ready for final trimming and welding.

I need to figure out how I want to close up the gap at the back of the targa bar so I started on a piece to help me get a feel for the shape I'll need.

I used a piece of 20ga, bent it to 90 degrees then went at it with the shrinker/stretcher.

And of course it curves both directions... But this was either an easy piece or I'm getting faster at working metal. It only took about 15 mins to get to this point.

And the clamps aren't adding much pressure, just holding things in place. The piece sits almost perfectly on the targa bar.

Jesus, I love this build.

Wow thats a major design change! Gives it more of a sleeper look than an outlaw or 916 look.

Certainly be much faster than making a roof! Im curious. Are you going to make a couple of wind holes in the rear of the top to allow for some pressure relief while the windows are down?

I've always wondered if people with GOOD seals had that issue.