Stepdown Roofs

Hienkel429

Hey all, 
Am currently blocking my roof, and besides the occasional small crease from a bump in the past, the entire roof is barely perceivably wavy.  You can only really see it with some guide coat, but I am assuming that this is normal and just wanted to confirm with other folks. 
Thanks, 
Ray

Hienkel429

Maybe not wavy, but more like ripples on a lake. 

Kdancy

These roofs are so big, it's not surprising. Sounds like yours has had some prior damage that caused the ripples.

Hienkel429

There were some creases from overhead damage in years past, but what is surprising is the flexibility of the roof.  I think the ripples might be a remnant of trying to stretch a large sheet of steel over a rounded form.  You're bound to get distortion somewhere in the metal. 

7XPacemaker

The 51 sedan that I restored had a lead repair under the original paint. I would say that the factory had a little “oops” moment. They slapped the lead to it and sent it packing. It was a nice repair so I left it there when I repainted it-

blondwookie

Lead repair we're standard body repair for years until Bondo became the normal. 
I've met and known a few that swore to lead over Bondo. All but a few are dead now.

Hienkel429

So after a week of dollying, shrinking and stretching.  Chasing highs and lows from one side of the car to the other, I am about done.  

I have made a drawing proposing a solution.  Under the areas that oil can and immediately rebound, I propose panel bonding some reinforcement metal bows.  Approximately 1/8 thick and 2 inches wide steel bent to the specific curvature of the roof with no welding and the only physical attachment being the 3M panel bond. I am not looking to fix the roof and the issues, more akin to stabilizing it so a thin skim coat of filler or glaze will sort the darn thing out.  



Has anyone tried a solution like this?  Pros and Cons?  I am all ears.  

Thanks all!

Ray

trdrew

I think this is a good solution. Bonding will avoid heat distortion. I had a '72 Mercedes that had similar "stiffeners" on the inside of the hood because it was such a low crown panel. If you were being a purist concerning the metal finishing, the solution would be very careful shrinking in the area that is oil canning, but this is a touchy thing to accomplish perfectly because of the extremely low crown of the panel (as you have discovered!).
I would make the stiffener bands about 2" wide & you could experiment with running a central bead or a bead on each edge to stiffen these bands sufficiently. Probably better to finish with the oil-canning areas slightly low than too high - you want to avoid having to hammer down high spots once the bands are bonded in. Should be able to finish nicely with a slight fill in those areas. Careful x-pattern blocking is your friend!

tombia

Several years ago I had a oilcan problem with a Model T body I did. Painted the inside with por15 and covered it with 2 layers of fiberglass matt, bonded with more por15, made it nice and solid.

Lance

I know this may sound weird  but how about another roof?   I have  them  but more importantly, if someone nearby can supply you with one, would that work for you?

Hienkel429

Tombia, 

Considered doing either fiberglass or a thick coat of fiberglass reinforced filler as a stiffener and was worried about stresses eventually popping it off.  The strength of the panel bond is absurd so no worries there. 

Lance, 

In a perfect world that'd be the ticket.  But after hours of driving, hundreds of dollars, then dozens of hours, if I can even find a suitable donor roof that was legit solid (this looked it when I bought it), this can be done for under a hundred bucks. 

Thanks all!

Hienkel429

trdrew, 

That is exactly the plan.  Glad to know I am not 100% crazy ??

Thanks!