Panelbeating : Oil canning in large panel

[halfdone]

My panel beater and I am having a problem with a panel

This is a long saga, so sorry in advance.

The panel in question is the back of a 48 F-1 pickup cab. The large, lightly crowned area below the window, mostly hidden by the front of the tray.

Problem to start with was the usual rust across the bottom and the curved bits behind the doors bashed around by a loose flat bed tray hitting the cab.

Made patches and hammer welded them in. Knocked out the dents. Bit of shrinking, File finished it. Beeeuuutifullll

Problem started when we went to reinstall the brace that goes inside, which we had removed to get access to panel beat.

We rosette welded (mig) it through the old spot welds........and it warped the panel big time. Lows and highs everywhere.  :oops:

We removed the brace again and oxy welded all the holes from the rossette welds back up.

Now we are trying to get the panel straight for the second time  :oops:

It was a mass of highs and lows, which we have slowly worked our way through. Too start with it was oil canning across the whole panel.

We now have it too the point where there are two areas about a foot diameter that still oilcan (in unison). Depending on which position you pop the panel it has a low and a high, or visa versa (if that makes sense)

No matter how much time we spend heat shrinking and using the slapper it isn't getting better. The two oil can areas can be moved around, but they are still there.

So far my beater has 14 hours into the panel.......and I am paying an hourly rate  

Good news is with the oil cans in the "right" position the high and low are shallow enough that a couple of heavy coats of high fill primer would have them OK.

Bad news is I need to reinstall the brace plus I am worried that if I high fill (or bog) it with the oilcanning still happening it will all fall out when I start driving the truck.

Another beater has suggested we glue the brace in with urethane glue (like late model quarter panels and firewalls). I like the sound of that idea.

He has also suggested we give the inside of the panels a REAL HEAVY hit of sound deadener with the oil cans dents in the RIGHT spot, then urethane the brace in, then high fill or bog it. He reckons the heavy sound deadener will stop it oil canning.

My beater is less than confident with this last lot of advise and is worried we will end up with a mess and that getting the brace back out and the sound deadener off again would be a show stopper.

He is now suggesting we slice the whole panel out, english wheel a new section and hammer weld it in........remember I am paying by the hour here    

Today I pulled the pin when he decided to try cutting a hole in the floor to get room to stick his arm in to have another go at hammer/slapper and dolly work

HELP......someone please make a brilliant suggestion  

Mark

[Pope Downunder]

My panel beater and I am having a problem with a panel

snip

We rosette welded (mig) it through the old spot welds........and it warped the panel big time. Lows and highs everywhere.  :oops:

snip
Another beater has suggested we glue the brace in with urethane glue (like late model quarter panels and firewalls). I like the sound of that idea.

He has also suggested we give the inside of the panels a REAL HEAVY hit of sound deadener with the oil cans dents in the RIGHT spot, then urethane the brace in, then high fill or bog it. He reckons the heavy sound deadener will stop it oil canning.

snip


Mark

I'm no expert, but I can tell you we had a similar problem with the back of my pickup.

The panel is now bonded to the bracing with urethane adesive, and it is as solid as a rock after five years.

Mine was an old mill truck and the back of the cab had copped a floggin'.  It was effectlvely pushed in about 3" overall, and covered in dents and had several large holes punched through.  The beater put 228 shrinks into it; after I did my best.  He seemed to imply that I might have stretched it!

[1FATGMC]

Get one of those "shrinking disks".  Do a "google search".  I had this problem before and the shrinking disk took care of it.  Someone really good can take care of it with a torch, but I usually never could.

I would not weld the brace in or you will end up with the same problem again.  Also where the brace is welded to the panel you can later get stress cracks in any bondo if you use it.  I've run into that problem with the brace across the top of my hood.

Glue it in or I would get it close to the panel and then use rubber or something else like the factory does to support the panel with the brace.

c ya, Sum

[unklian]

Sounds like you need a new "panel beater".

[halfdone]

I probably made it sound like my beater isn't particularly good.

The exact opposit is the case. He is a restorer who an EXTREMELY good old style beater who only does all metal, file finished work on vintage Fords.

He absolutely refuses to use any filler other than leading the factory joints.

He is HIGHLY in demand and getting him to work on rods for me took years of pursuading.

He has done lower body patches and an EMS tailpan on my 36 Coupe for me and it was a work of art. All hammer welded and file finished. Good enough that with a single pass of etch primer you couldn't see the work.

He is doing the rust patches on my Victoria and I have ALMOST talked him into doing the roof chop. (Only if I promise not to tell the other restorers   )

SO......if he can't get it straight after 14+ hours of slapping and heat shrinking, and he is the best panel beater around these parts......what next ??

The really stupid bit is this truck is being build in "Patina", as in as found paint on the cab and bed. So the back panel doesn't need to be perfect.

In fact the front panel of the bed isn't straight so you won't be able to tell if the cab panel is straight.

I am just worried that the other beaters suggestion that I use sound deadener to firm up the panel and then high fill it won't work and I will be worse off than now.

[unklian]

I would wonder how much stiffnes you would get out of Sound Deadener.

Glueing in the cross piece does sound like a good idea.

[enjenjo]

No offense to your panel beater, but if it's not getting better, he's not doing the right thing. Sometimes the stretched metal is outside the area it seems to be. And other times the metal has shrunk in another arera that causes the problem.

What I have seen done in some of these cases, is to work a bend into the metal, enough to hold it from oil canning, and then fill over it.

I have used panel adhesive to hold braces into place with no problems.