Topic: Cowling Repair

[koski19]

I spent last night and today removing the cowling top to expose the hats. The lower cowling seems to be in good condition there is rust but it has not eaten through. I used a stripping pad and the rust looks to be surface. I poured water into each area of the hat to check for leaks. I didn't notice any leak on the interior of the Mustang but the hat area on the passenger side dried up faster than the driver's side. My plan is to replace the hats and the top cowling assembly. My question is that I have drilled through some of the spot welds and I read this shouldn't be done. So, how do I fix this when it comes time to install the cowling top? There is also quite a large gap between the lower cowl assembly and the firewall panel top now that the top cowl is removed. Will these to pieces come together when the top cowl is installed and welded in place? I'll attempt to post some photos later..........Jeff

[koski19]

I spent last night and today removing the cowling top to expose the hats. The lower cowling seems to be in good condition there is rust but it has not eaten through. I used a stripping pad and the rust looks to be surface. I poured water into each area of the hat to check for leaks. I didn't notice any leak on the interior of the Mustang but the hat area on the passenger side dried up faster than the driver's side. My plan is to replace the hats and the top cowling assembly. My question is that I have drilled through some of the spot welds and I read this shouldn't be done. So, how do I fix this when it comes time to install the cowling top? There is also quite a large gap between the lower cowl assembly and the firewall panel top now that the top cowl is removed. Will these to pieces come together when the top cowl is installed and welded in place? I'll attempt to post some photos later..........Jeff

Here's the photos I added 4..Hope they show up.....Jeff

[mustang65ld]

Just plug weld the hole. You can just use a piece of copper underneath because it won't accept the weldment. Grind it flush and you should be good to go to reinstall and re-weld the top.

Have fun.

[koski19]

Thanks for the tip. I ordered the cowl top hat patch pieces today..Hopefully, next week I can finish the repair.

jeff

[cobrajetchris]

I looked at the photos you uploaded and based on that and your description of the condition of the lower cowl panel, I would not replace the panel with reproduction sections. I would start by using a wire a brush or better yet sand blast the area on each side and then inspect to see the extent of the corrosion. In my opinion if there is only some minor pin holes in the panel I would brush an epoxy primer on both sides of the panel and use a two part seam sealer such as 3M 8310 bare metal to seal all the seams around the hat and any pin holes. I would then refinish both sides except for the plug welding areas to install the top panel. If you section in 2 panels you are creating more seams and more chances of leaks and possible fit issues. When you reinstall the top panel make sure it's in the exact original spot (line up the original spot welds) or you will have fit issues. 

[koski19]

I looked at the photos you uploaded and based on that and your description of the condition of the lower cowl panel, I would not replace the panel with reproduction sections. I would start by using a wire a brush or better yet sand blast the area on each side and then inspect to see the extent of the corrosion. In my opinion if there is only some minor pin holes in the panel I would brush an epoxy primer on both sides of the panel and use a two part seam sealer such as 3M 8310 bare metal to seal all the seams around the hat and any pin holes. I would then refinish both sides except for the plug welding areas to install the top panel. If you section in 2 panels you are creating more seams and more chances of leaks and possible fit issues. When you reinstall the top panel make sure it's in the exact original spot (line up the original spot welds) or you will have fit issues.

Thanks for your view point...My thought was to replace the hat sections since I removed the top. I find no rusted through metal in either the hats, top or lower sections, just surface rust and no pitting. I wanted to replace the hat sections just in case they did leak. I'll be cleaning up the cowling lower half this week.
Jeff

[Turnbacktheclock]

I am faced with similar cowl issues. The lower cowl is pretty solid but the hats had pin holes along their bases and leaked watering into the passenger compartment. I am struggling with the decision whether to open up the cowl or just use the plastic hat repair kit.  Maybe if you just cut the spot weld holding in your rusty hats and plug welded in new hats (which you remove from the patch panels you purchase), you could avoid all the issues of fitting and welding and grinding patch panels and yet be confident that your cowl will be better than new.

Has anyone ever repaired their cowl this way? Any down side to this method?

66 GT SJ Coupe

[CharlesTurner]

Thanks for your view point...My thought was to replace the hat sections since I removed the top. I find no rusted through metal in either the hats, top or lower sections, just surface rust and no pitting. I wanted to replace the hat sections just in case they did leak. I'll be cleaning up the cowling lower half this week.
Jeff

Think you may be introducing more potential problems than you already have by replacing the hat sections.  Would recommend to clean the metal thoroughly, preferably by blasting, then epoxy prime.  Some self-leveling sealer might be a good choice, would defer to a professional body man for a recommendation.

[koski19]

Think you may be introducing more potential problems than you already have by replacing the hat sections.  Would recommend to clean the metal thoroughly, preferably by blasting, then epoxy prime.  Some self-leveling sealer might be a good choice, would defer to a professional body man for a recommendation.

Attached are some photos of the lower cowl panel and the hat sections. I spent this evening cleaning, removing paint and rust. I found no rusted through areas, no pin holes in the hats or around them. My thought now is to use a seam sealer around the outside of the lower cowl and around the base of the hats on each side instead of replacing the hat sections with the patch panels. Then coat the entire lower cowl with rust bullet or Por-15,  install the top cowl section spot weld and seam seal it. As I was thinking about this, how is the lower cowl painted? Before the upper cowl is installed or after?

Jeff

[CharlesTurner]

The lower cowl typically would have been galvanized steel and then received any primers/paint that came through the vents as over-spray.  It would be in your best interest to use a quality coating like a catalyzed epoxy primer, followed up with a top-coat of gray sealer primer. 

[koski19]

The lower cowl typically would have been galvanized steel and then received any primers/paint that came through the vents as over-spray.  It would be in your best interest to use a quality coating like a catalyzed epoxy primer, followed up with a top-coat of gray sealer primer.

Would the final color paint be sprayed down through the vents as well? typically an over spray? I would think a seam sealer would be used between the top and bottom before spot welding it back together or weld through primer?

Jeff

[cobrajetchris]

The upper cowl was welded in place before the painting process and whatever paint blew into the vents is what it got. Weld through primer is fine for in between the welded surfaces however you want to clean off the plug weld area as the primer will cause a poor weld.

[koski19]

I think one last question for this topic.....Why is there no replacement top cowl available? I searched my catalogs of Mustang parts and seem that one can only purchase the complete cowl assembly, the lower cowl, patch panels for the hat sections or repair kits for the hats. I found no top cowl available. Just curious here.

Jeff

[CharlesTurner]

There is a 2-piece section sold, not sure why just the top is not available.  http://www.cjponyparts.com/cowl-panel-assembly-2-piece-1965-1966/p/COWL1/

In your case, I would never consider replacing a perfectly good top cowl piece with a reproduction.  I would highly stress to not remove parts as structurally critical as the cowl unless absolutely necessary.  I would also highly recommend to patch panels if possible before replacing entire sections.  For instance, patching the bottom of the battery apron instead of replacing the whole piece.  There will be major fit issues if good original Ford metal is swapped out for inferior replacement sheet metal sections.

[koski19]

Thanks for the info.......I'll probably keep the top cowl and reinstall it. Been doing alot of thinking today.....

Jeff