Compound curve is no longer snug after raising bottom area

[darkie]

Good Afternoon,

I am attempting to make a patch for the inner fender.

I managed to get the upper piece to fit relatively snug, as can be seen in the picture:

Here is a picture of the actual patch:

So how do I tip the blue curved area without distorting the already flush fitting bottom area ?

Should I overshrink the upper piece (Horizontal shown in green) a bit over first? and then it should come down after I tip the bottom area down?

What affect on the metal will tipping the curved area have on the upper area in in green?

BONUS points if you can tell me a decent discord for Autobody

I only have hand tools.
Thanks for your time and have a great day!

 

[darkie]

I think you want to do stretching along the blue line, but perpendicular to the blue line. Not 100% though I'm sure someone who knows more will chime in.

I want the blue line to tip down, question is how to do it without disrupting the green area

 

[daedalusminos]

I assume you don't have a shrinker?

In which case I'd try making it out of 2 or 3 separate pieces welded together

 

[tigdlo]

Stretch the middle and shrink the edges, start with shrinking so not to have to make the middle too thin.

Check youtube for "tuck shrinking" instructions, this is a good method for fast shrinking with minimal/cheap tools.

 

[tigdlo]

I want the blue line to tip down, question is how to do it without disrupting the green area

You may not be able to, it is all attached together, the chances are it will need some correction afterwards, this is just how it is.

 

[Burdekin]

Make it out of thin cardboard and see what needs doing. Great way to visualise and work out what is required. The easiest way will probably be to do in two parts and weld, or add some slits in the tipped area where it needs shrinking or shrink the area so you maintain the curve of the inner arch.

Also make it larger and trim back to size once you have the shape.

 

[tom2207]

straight onto you tube and watch some Wray Schline or Ron Covell videos or Lazze ,,, pictures being worth a thousand words

Wray explains the flexible shape pattern way of working very well .

 

[darkie]

I assume you don't have a shrinker?

In which case I'd try making it out of 2 or 3 separate pieces welded together

I have a shrinker, so i should. _________?

 

[darkie]

You may not be able to, it is all attached together, the chances are it will need some correction afterwards, this is just how it is.

How do I correct it after?

 

[tom2207]

Go watch Wray Schelin , I wouldnt start by cutting that up for such a gentle shape , or you will be making another one.

 

[tigdlo]

How do I correct it after?

More shrinking and stretching.

Post a photo of the inner arch so it is more clear what you are trying to acheive.

Most of the shape will be made by shrinking left of the blue line, IMO that should be done first to get you close to what you need before moving on. You can physically push the repair panel into place right of the blue line to see how much extra material you have left of the blue line.

 

[darkie]

More shrinking and stretching.

Post a photo of the inner arch so it is more clear what you are trying to acheive.

Most of the shape will be made by shrinking left of the blue line, IMO that should be done first to get you close to what you need before moving on. You can physically push the repair panel into place right of the blue line to see how much extra material you have left of the blue line.

Inner arch:

 

[Spot the welders dog]

I would flip the repair panel over and on the rear chase the 'tipping' line with a blunt chisel first (easy way to demonstrate is to scribe a line into cardboard and you can observe that any crease will naturally follow the indentation).
Flip it back over and using a suitably radius dolly/former (fashioned from what ever you have), securely clamp the 'yellow' portion then start tipping. I'd use a slapper, lump of wood, over a body hammer for a wider point of contact.

https://www.mig-welding.co.uk/forum/threads/metal-shrinking-stretchers-experts.89955/page-2