Topic: Roof Nightmare Decision

[Angela]

I'm Working on my '70 Mach1, which I stripped to bare steel and replaced two small sections of the floor pan, else she's all original steel. It's on a rotisserie now and after a couple years worth of body hammer work, I had it almost nearly ready for primer with only a skim coat of filler.

But, while sanding filler where the old factory lead used to be (roof to quarters) I discovered I had a small (8" dia) area which was oil canning. I attempted to fix the oil canning, but only made it larger (~12" dia area). So, I stopped and sought professional help.

After a month of searching, I found a reputable classic car restoration shop which stated they had experience with this exact type of problem and could help. I made an appt for a week later.

After 1.5hrs of their efforts, the roof is essentially destroyed. They moved the oil canning from one corner of the roof all the way to the other. The entire roof looks like it was beat with a 3lb sledge hammer. And, as a bonus, it's oil canning in at least six places now. I do realize oil canning is a nightmare to solve, but with respect, it does not appear they were experienced with metallurgy and the correct way to address this type of repair.

I suspect there are probably a handful of people on the planet who could save this roof, but I don't know any of them.

So, I see two options:
(1) I could start cutting slits in the roof, weld them shut which *might* stop the oil canning. If it does, I'd save the original panel, but it would require at least 3/8" thick filler to level the mess across the entire panel (I measured using a straight edge).
(2) Start cutting the roof skin off and replace it.

I'm not quite ready to make a decision. Rather, I'm looking for advice concerning new roof skins. I have the following questions:
(a) Does anyone have a link to a write up describing how to remove the roof skin?
(b) Are all of the available roof skins made in Taiwan and I should expect they will fit terribly? or, is there a specific supplier which you guys would recommend wherein the new skin fits better?
(c) Do replacement skins include the drip rails/gutters, or would I somehow need to save the originals (which I find unlikely they'd survive)?

Any/all help would be appreciated. Thanks.

[Bossbill]

A good metal worker might be able to save the existing mess.

Where in the U.S. are you located and how far are you willing to travel?

[cobrajet_carl]

Sven Pruett replaced his roof with a Dynacorn part and was happy with the quality and fit, which he has not always been with repro stuff. The write-up is very detailed with lots of pictures. Even though he is doing a restomod his blog has a lot of good info for the concours restorer.

http://1970boss302.blogspot.com/2013/03/replacing-roof-skin-part-1.html
http://1970boss302.blogspot.com/2013/04/replacing-roof-skin-part-2.html
http://1970boss302.blogspot.com/2013/05/replacing-roof-skin-part-3.html
http://1970boss302.blogspot.com/2013/05/replacing-roof-skin-part-4-done.html

[7Lscjracer]

Sorry to hear about this frustrating situation.
One would expect a restoration shop to not make the problem worse.
It would help to know what you did to try and shrink the oil canning patch, and what method the shop used too.
Was the area heated with an O/A torch or a Mapp gas torch, then dinged a couple of times with a body hammer before cooling with an ice water rag?
This takes skill and experience to improve the situation and can easily make things worse.
Were dings or taps made with a body hammer with a dolly underneath on the inside?
Don't do that, it stretches the metal by squashing it thinner, and the idea is to shrink the metal.
Was a stainless steel shrinking disc used on a 7" grinder?
It's the safest way, doesn't make too much heat and only hits the high spots that you need to ding or tap down.

[Bob Gaines]

I'm Working on my '70 Mach1, which I stripped to bare steel and replaced two small sections of the floor pan, else she's all original steel. It's on a rotisserie now and after a couple years worth of body hammer work, I had it almost nearly ready for primer with only a skim coat of filler.

But, while sanding filler where the old factory lead used to be (roof to quarters) I discovered I had a small (8" dia) area which was oil canning. I attempted to fix the oil canning, but only made it larger (~12" dia area). So, I stopped and sought professional help.

After a month of searching, I found a reputable classic car restoration shop which stated they had experience with this exact type of problem and could help. I made an appt for a week later.

After 1.5hrs of their efforts, the roof is essentially destroyed. They moved the oil canning from one corner of the roof all the way to the other. The entire roof looks like it was beat with a 3lb sledge hammer. And, as a bonus, it's oil canning in at least six places now. I do realize oil canning is a nightmare to solve, but with respect, it does not appear they were experienced with metallurgy and the correct way to address this type of repair.

I suspect there are probably a handful of people on the planet who could save this roof, but I don't know any of them.

So, I see two options:
(1) I could start cutting slits in the roof, weld them shut which *might* stop the oil canning. If it does, I'd save the original panel, but it would require at least 3/8" thick filler to level the mess across the entire panel (I measured using a straight edge).
(2) Start cutting the roof skin off and replace it.

I'm not quite ready to make a decision. Rather, I'm looking for advice concerning new roof skins. I have the following questions:
(a) Does anyone have a link to a write up describing how to remove the roof skin?
(b) Are all of the available roof skins made in Taiwan and I should expect they will fit terribly? or, is there a specific supplier which you guys would recommend wherein the new skin fits better?
(c) Do replacement skins include the drip rails/gutters, or would I somehow need to save the originals (which I find unlikely they'd survive)?

Any/all help would be appreciated. Thanks.

Sorry to hear you going through this frustrating situation. Curious if you had to pay the shop for their botched effort and what they had to say about making the matter worse?

[Coralsnake]

Sorry also

Please dont let that shop do anymore work

And stay away from option 1, filler should never be that thick

[J_Speegle]

I'ld plan for a new roof skin for all the reasons mentioned

Old used cars are full of surprises unfortunately that can present themselves at any time.

Keep the focus on the end product and goal - this will be in your rear view mirror before you know it

Good luck with your choice

Going to move this thread over to the Body section because its not really just about 69-70's but owners with other years my benefit from the challenge and figuring out your best path

[67gta289]

I have access to several 69 Mach 1’s near me.  From the belt down are Swiss cheese but there should be a good roof or two. 

[Angela]

Thanks for the feedback guys. I'd add a couple pictures, yet for reasons I don't understand, I'm not enabled to upload pictures to this forum.

There was oil canning present, yet there were no dents prior to hiring the professional restoration shop. Afterwards, the roof now has at least 150 marks from a heat shrinking tip (stud welder) and no less than two dozen dents from a 3lb hammer.

I don't want to cut up an all original car. Sadly, I don't believe I have any other option than to replace the roof skin.

I haven't received a bill from the restoration shop yet. If I do, the discussion is going to get a little "tense".

I'm located in MN. At present the car is on a rotisserie and I do not presently own a car trailer.

[Coralsnake]

Dont feel obligated to keep it there.

You are asking for more trouble...

I had a CJ motor built many years ago, the engine didnt oil properly. I had to pull the motor. I sent it to another shop. Shop #1 wanted a second shot. No way Jose and a refund please.  You are encouraging them to keep experimenting with your money.

[Angela]

"Dont feel obligated to keep it there.  You are asking for more trouble..."

I've been giving that a lot of thought and I suspect you're right. On one hand they have ruined my roof and I think it's appropriate that they help make it right (for example by helping with the labor to replace the roof skin). On the other hand, they ruined my roof and thus I should part ways before something else is ruined.

I do respect the time they invested to try and help me. I also respect the fact that they were willing to come to my shop and try to help. What troubles me is that I specifically verbalized the fact I was seeking assistance from someone skilled in the art of metal working who has successfully repaired oil canning. They said they had both skills. They clearly did not. Ugh.

I contacted Dynacorn which stated their roof skin only comes in weld-thru-primer and is 16Ga steel from Taiwan. I'm having a tough time finding feedback from those who have replaced roof skins, but the feedback I have received seems to suggest that Dynacorn is probably the best option for someone faced with this situation.

Alternatively, I could spend months searching for a used Ford roof from a donor car. I was trying to get the car primed by spring, thus I'm not sure I want to (or have the time and energy) go down the path of a donor car. I need to give this a little more thought.

For now, I've ordered a Blair spot weld cutter. I can at least begin the process to make templates for alignment and remove the original roof.

Thanks!

[tobkob]

What general area are you located? I know of several donor cars if you are close enough to pick up in SE Tennessee. You can PM me if you are interested. 

TOB

[67gta289]

Did you see my post #7 reply?   Won’t take months...

[tobkob]

Did you see my post #7 reply?   Won’t take months...

   

[Bossbill]

Post #8 says MN.