[SinistrV6]

My '36's firewall was already filled when I got it. I like that look but drilled a couple of holes in it to mount the gas pedal and two more to mount the shorty column brace. Long story short, I don't like it and want to remove those bolts and weld them shut again. The column brace can be welded in but the pedal (and a few other items) should be removable. Should I just weld the bolts/studs to the firewall on the inside?

Thanks,
Richard

[S10xGN]

Hey Rich,

I like "Rivnuts" and SS buttonhead machine screws...

Russ

[SinistrV6]

Originally Posted by S10xGN

Hey Rich,

I like "Rivnuts" and SS buttonhead machine screws...

Russ

I like those too but they don't achieve the smooth goal. I need threaded studs attached to the inner firewall with nothing showing on the engine side.

[evolvo]

While I was building my car I welded bolts and/or nuts on the inside of the firewall to use as mounting points. Usually welded in a few extras for future use. I used them to hang relays, wire clamps and my Vintage air unit.

In this photo you can see the nuts welded on the firewall that I used to mount the MAP sensor

http://www.hotrodders.com/gallery/da...0-2004_IMG.JPG

Click on the photo for a better view

[MARTINSR]

Do not weld a stud on the back of the firewall where anything of any weight or force will be applied like a gas pedal. It WILL show on the outside after a little use. You need to spread out that force, welding the stud to a flat piece of metal then weld that metal to the firewall with a number of welds will often work. How about welding the stud to a flat piece of metal and then bond that piece of metal to the back of the firewall with structual adhesive would be another good way to go.

Brian

[SinistrV6]

Originally Posted by MARTINSR

Do not weld a stud on the back of the firewall where anything of any weight or force will be applied like a gas pedal. It WILL show on the outside after a little use. You need to spread out that force, welding the stud to a flat piece of metal then weld that metal to the firewall with a number of welds will often work. How about welding the stud to a flat piece of metal and then bond that piece of metal to the back of the firewall with structual adhesive would be another good way to go.

Brian

Great info! Thx

[66GMC]

Originally Posted by MARTINSR

Do not weld a stud on the back of the firewall where anything of any weight or force will be applied like a gas pedal. It WILL show on the outside after a little use. You need to spread out that force, welding the stud to a flat piece of metal then weld that metal to the firewall with a number of welds will often work. How about welding the stud to a flat piece of metal and then bond that piece of metal to the back of the firewall with structual adhesive would be another good way to go.

Brian

That sounds like a very elegant and flexible solution!
The 1-minute or even 5-minute adhesive would allow for proper positioning and alignment before it set up, too.

[Irelands child]

Why not add some inner bracing like a square steel framework. I added a set of reinforcing bars to my '31 and mounted almost everything to them. I did the entire car, but this is some of what is under the dash:



And my firewall:



Dave W

[delawarebill]

i had the same problem while building my bucket.. 2 pc's of 1/2" plywood fiberglassed to the inner f/w and that solved my problem... attach everything now...

[Irelands child]

Originally Posted by delawarebill

i had the same problem while building my bucket.. 2 pc's of 1/2" plywood fiberglassed to the inner f/w and that solved my problem... attach everything now...

Yep - forgot that I did that to my bucket - but not as easy if it's a steel car

[evolvo]

Originally Posted by MARTINSR

Do not weld a stud on the back of the firewall where anything of any weight or force will be applied like a gas pedal. It WILL show on the outside after a little use. You need to spread out that force, welding the stud to a flat piece of metal then weld that metal to the firewall with a number of welds will often work. How about welding the stud to a flat piece of metal and then bond that piece of metal to the back of the firewall with structual adhesive would be another good way to go.

Brian

Hey guys,
I didn't mount anything heavy or moveable on those studs/nuts. That MAP sensor must weigh all of 3 oz. !! I also used the zip ties with a stud hole on the end to secure my wire runs, I don't think that will cause much problem.
Martins solutions are quite elegant, just wasn't required in my case.

[MARTINSR]

I didn't mean to say you did it wrong. I just wanted to make it clear that if anything of weight or something that will be subject to some forces like a throttle pedal will cause that stud to move a little and show on the other side. Depending on how Psycho one is, even just welding the stud on and putting something light weight on it may show a "ghost" mark on the other side if your firewall was glass flat cut and buffed black paint.

It is VERY easy to end up with a "ghost" spot on the outside when ever something is welded to the back side. Just a TINY bit of movement to that stud or tab or what ever you are welding is going to show on the outside.

Brian

[TucsonJay]

For welded studs, check out "elevator bolts" at your hardware store.

While I am talking about them...

You can also use them on fiberglass by cutting off part of the flange on each side, so it can't rotate inside the 'glass.

To attach to 'glass, just grind the surface to expose fibers... push a couple layers of mat or cloth over the threads... position the stud... and soak the mat/cloth with resin.

Here is a picture attached below...

[JMBO]

On solution I have found is to weld Elevator bolts to the inside of the firewall. The large flat head welds well and spreads any stress out over a large area.

[cyclopsblown34]

Jay, thanks for the idea, I sell that stuff all day long here at work as well as rod ends (Heim joints). Imma have to stock up on some of that stuff.