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How do you refinish a firewall?

5K views 7 replies 6 participants last post by  Henry Highrise 
#1 ·
I have a 67 Camaro that I am in the middle of restoring and need some help restoring the firewall. I see pictures all over the place of these beautiful firewalls and want that for my car as well. As you can see in the picture, some moron decided that there would be more distributor clearance it they beat the fire wall back with a hammer.

The damage from the hammer also damaged the seam between the cowl and the firewall. The subframe is out from under the car so the firewall is easily accessible. The last thing I want to do is spend a lot of time redoing this just to have problems with the paint in a year or two because I did not prep it right. I am now to this hotrod thing and have no idea where to begin. All the input I can get would be greatly appreciated.

Thanks,
NoClone
 
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#2 ·
I have smoothed a few firewalls on those cars. The only digital pics I have are of a 70 Nova that I did for my neighbor. Pretty much the same firewall. This firewall had also been hammered in to accommodate a late model dist.
I used a hammer and dolly to give that area a nice uniform shape since the clearance would still be needed.
Where the uppercowl, innercowl and firewall meet I used a cut off wheel to trim the overlapping panels so that they had the same edge. Then welded that new edge up.
Welded up all holes that were not needed.
Ground all welds
Used fiberglass reinforced filler over the seams.
Skimmed most of the firewall with filler
Primed
Painted.








 
#3 ·
If you want that firewall to look original, you are going to need to do some surgery. If you do want to repair that hammered in area to original we can walk you thru it. It would be pretty easy going up to the seam and drilling out those spot welds. Then cutting down both sides and across the bottom and weld in a new piece. If there is any place to try such a thing for the first time, that firewall is the place.


Doing things like the firewall are all about detail. Making it better than original. It is pretty easy, just very time consuming. Clean up the seams, removing all the seam sealer. After priming you run a tape line on each side of the seam and then apply a urethane sealer, pressing it into the seam good. Remove the tape and you have a perfectly sealed seam.

If you want to semi smooth the metal, polyester primer will get you a long way. If you want to totally smooth it, refer to the previous post. You can do just about anything you want, it is all up to you.

Brian
 
#4 ·
This is not an uncommon problem and looking at the hammer job, if your restoring to factory you will find it faster and easier to find a junk yard and have them cut one out for you. Last one cost me about $75 and at the stage your at you can cutout and replace in about 2 hours without killing yourself.
 
#5 ·
I like the look of that firewall! I would have to say that what you have done there is pretty close to what I am trying to accomplish. I am no body guy and have never really had any experience with it although I am certainly willing to try. Could you tell me what type of materials you needed to get this done. How thick can you go with this filler and will the heat from my headers cause it to breakdown? I have already started to smooth it with a hammer and dolly but you can only get it so smooth with that. The firewall is basically back to it's original location. Do I need to sandblast it to get a good clean surface to work with or will sanding it do the job. Again, I apologize for asking a few stupid questions, but this is all new to me.

Thanks,
NoClone
 
#6 ·
going to bare metal is your best bet. Sandblast or grind/sand, your choice. I like to use the 3m rust srtipping wheels on a die grinder for tight areas like a firewall. You should do all your hammering and welding at the bare metal stage. The biggest area of concern with using filler on that firewall is the area around the heater box. That area is prone to "oil canning" or flexing. Especially when installing the heater box. If you use filler here it is prone to cracking. The filling should mainly be done over the seam if you are going for the smooth look. The seam should be welded up. As far as thickness goes use a fiberglass reinforced filler over the seam. And regular filler for the light filling. Keep it as thin as possible. Any where that stuff mounts to the firewall should have little to no filler if possible to avoid problems with flexing and cracking later.
 
#7 ·
firewall madness

hey guys hows it going? i know this is the same question asked over and over. i want to smooth my firewall on my 70 nova. everything is off of it except for the master cylinder and motor for the wipers. what would i need to do? i new to this and hopfully you guys can help me out. red sled
 
#8 ·
red sled said:
hey guys hows it going? i know this is the same question asked over and over. i want to smooth my firewall on my 70 nova. everything is off of it except for the master cylinder and motor for the wipers. what would i need to do? i new to this and hopfully you guys can help me out. red sled
Read this entire thread....it pretty much covers everything.
 
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