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  #1  
Old 09-17-2021, 11:06 AM
69rrbruce 69rrbruce is offline
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Default Help with roof insert

Looking for some advice from the experts here. I have a 36 Ford 5W Coupe that already has a roof insert welded in. The problem is that the middle has more crown than I think it should have. Also, around the welded perimeter the shape appears to run lower than perimeter of stock roof before rising up to crowned area. I'm wondering what you guys think happened and what would be the best way to rework it? Specific methodologies would be greatly appreciated.
Below i've attached a pic, but it's kind of hard to show it.
36 Insert front view (2).jpg
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Last edited by 69rrbruce; 09-17-2021 at 11:28 AM.
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Old 09-17-2021, 11:47 AM
crystallographic crystallographic is offline
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Originally Posted by 69rrbruce View Post
Looking for some advice from the experts here. I have a 36 Ford 5W Coupe that already has a roof insert welded in. The problem is that the middle has more crown than I think it should have. Also, around the welded perimeter the shape appears to run lower than perimeter of stock roof before rising up to crowned area. I'm wondering what you guys think happened and what would be the best way to rework it? Specific methodologies would be greatly appreciated.
Below i've attached a pic, but it's kind of hard to show it.
Attachment 61384

Can't see how it was welded, but welding does shrink, no matter which method, and welding will bring those edge areas down flatter, as we think we are seeing in this picture. Straight edge application to the surface, both across the weld and along the weld can better illustrate so the camera can then show contours clearly.

And so we stretch the weld areas back up, using hammer/dolly or handheld planisher, to recover the shrinkage.

But this operation itself may not fully resolve your further issue of the center crown being too proud. This involves shrinking, and the methods you have available to you may not be fully feasible to do this to satisfaction.
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Last edited by crystallographic; 09-17-2021 at 11:50 AM.
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  #3  
Old 09-17-2021, 03:51 PM
Jaroslav Jaroslav is offline
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A C hammer in the frame would solve it in a moment. If it is necessary to reduce, the shape by heat and cool ?? It takes experience.
DSC07299.JPG
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Old 09-17-2021, 06:42 PM
crystallographic crystallographic is offline
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Originally Posted by crystallographic View Post
Can't see how it was welded, but welding does shrink, no matter which method, and welding will bring those edge areas down flatter, as we think we are seeing in this picture. Straight edge application to the surface, both across the weld and along the weld can better illustrate so the camera can then show contours clearly.

And so we stretch the weld areas back up, using hammer/dolly or handheld planisher, to recover the shrinkage.

But this operation itself may not fully resolve your further issue of the center crown being too proud. This involves shrinking, and the methods you have available to you may not be fully feasible to do this to satisfaction.

Hammering the welds out with a handheld planishing hammer:
(gas welded, Rattle A roof filler panel, metal finished, primer -> paint.)
gas weld, steel, 20ga,.jpg

gas weld, steel, 20 ga, hammered.jpg

steel roof panel, ready to weld.jpg

steel weld, hammered, hammer on right.jpg

Handheld hammer, working out the roof weld.jpg

roof panel, welded, hammered, filed.jpg

roof panel welded, metal finsihed, front view.jpg

roof metal done, L side.jpg

roof metal finished, rear view.jpg

Ram's Head die set, partial.jpg


(3 piece steel panel simulates orig roof, w/eyebrow/rain-rail details spot welded and soldered)
Got a lot of scrutineers at the meets.
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  #5  
Old 09-18-2021, 05:10 AM
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Gojeep Gojeep is offline
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If the insert was correct before welding, you know it is only the welding that changed it as it shrank when cooling. Press up harder with your dolly than you are hammering down directly on it from above and it will stretch and lift it back.
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Old 09-18-2021, 07:30 PM
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drivejunk drivejunk is offline
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The only thing I might humbly add is this:

Your situation being what it is, fairly wavy...

If a guy was to make half a dozen vertial cardboard templates as-is, that fit across the roof from drip rail to center with one pair over each: near front, near rear, then a center pair over the B pillar-ish...

...and he trimmed those until fully closely fitted, and marked a level line on each...

then he was to lay halves over one another and average the contours (correcting where obvious), why then he'd have himself an initial target crown to shoot for. A handy quick-check go or no-go gauge for while he planishes each section. Revisions may be required as he sneaks up on it, but initial side to side radius comparison of halves would likely give a rough idea of where the bigger problems are.

Planishing is most of the answer, and flexible yardstick in good hands can help guide each side of the filler individually and thats a good way once it's ironed out a little but right now you have a bit rougher of a sketch than that and it is murder trying to restore order without some sort of guide. Because my eyeballs can't always pick out whats wrong and the potential for going off course majorly is so high.

I say this as input learned from a ribbed insert job on a chopped Model A. Roof sides were total chaos as was the rear panel that a tree fell on, etc. When something is all out of whack like that, I need a guide even if it is crude. Fortunately in my case the original wood supports were something I could start from.

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Old 09-19-2021, 11:27 AM
John Buchtenkirch John Buchtenkirch is offline
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You were wise to add a photo, I’ve never been help to anyone from a description of a problem. It’s even hard for me to comment without running my hand over the panel to feel what’s going on.

I would get some sheet steel strips sheared (16 or 18 gauge, 1” to 1 ” wide) and lay them on the roof after you’ve crowned them a bit. With a bit of tweaking you should be able get the crowned strip to lay on the roof where it flows and looks correct to your eyes. You might have to move the car outside to get a more distant perspective. When that strip looks like it flows correctly with the roof skin it will show you right away where your low spots are. Some lows may be able to be bumped up with an appropriate dolly with some weight to it. Where you’ve welded will likely need on dolly hammering to stretch out the shrinkage and correct the panel flow. Progress should be constantly checked with the steel strips. I’ve had problems trusting wood roof ribs as a guide, they just weren’t accurate to be a guide for a flowing steel roof IMO. Good luck, this job may take some time . ~ John Buchtenkirch
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Last edited by John Buchtenkirch; 09-19-2021 at 09:16 PM.
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Old 10-01-2021, 12:05 PM
69rrbruce 69rrbruce is offline
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Thank you all for your responses.
It looks like I need to create some metal strips to establish the desired crown and to see where in fact the metal is either too low or too high.
I'm going to start by plannishing the welded area in hopes that it will raise the adjacent area. Then I'll deal with the crowned area.
What are your opinions as to whether or not welding this roof insert caused the middle area to crown, or do you think the roof insert was over developed before welding?
Looking at this another way, if prior to welding in place, a sheet metal panel is over developed, what would be the process to reduce it's crown?
Does this process change once the panel is welded in place?
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Old 10-01-2021, 03:31 PM
crystallographic crystallographic is offline
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Quote:
Originally Posted by 69rrbruce View Post
Thank you all for your responses.
It looks like I need to create some metal strips to establish the desired crown and to see where in fact the metal is either too low or too high.
I'm going to start by plannishing the welded area in hopes that it will raise the adjacent area. Then I'll deal with the crowned area.
What are your opinions as to whether or not welding this roof insert caused the middle area to crown, or do you think the roof insert was over developed before welding?
Looking at this another way, if prior to welding in place, a sheet metal panel is over developed, what would be the process to reduce it's crown?
Does this process change once the panel is welded in place?

I'd suggest that you:

1) Make the metal "contour check strips" and check the contours.
2) Planish the weld areas ... best to pick a real flat area and see how much your hammer and dolly can bring it up - counting the swats needed as you go. (technique, technique, technique)
3) Check contours with strips as you go.
4) As you bring up the welded flat areas you will notice that the crown likely does not change - but that its crown might appear to be lessened, somewhat.
5) Establish how high the crown is, after planishing the welds, by measuring 1/16's.

Then it will be time to figure our how to reduce the "over developed" crown.
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Last edited by crystallographic; 10-01-2021 at 03:35 PM.
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  #10  
Old 10-04-2021, 08:53 AM
69rrbruce 69rrbruce is offline
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Thanks Kent
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