View Full Version : Bending PotMetal parts

01-06-2009, 08:15 PM
I've heard you can bend Pot Metal parts with a "little" 170F (?). Has anyone tried this and how would you know it's 170F? Hammering heat did nothing. Thanks.

john walker
01-06-2009, 08:21 PM
pot metal usually breaks when you try to alter it's shape, heat or not.

01-06-2009, 08:24 PM
pot metal will eventually melt ,explode or break. i've found that making small cuts in the side that won't be seen and slowly,real slowly bend it cold in the direction you want to go.

01-06-2009, 08:25 PM
Depends on the part and how it is being bent. 55,56,57 Nomads commonly have their liftgate windows bend out of shape. This is because the heavy torque put on them from the orginal design. There a couple of guys how have made jigs and then bend them (slowly) back into the right shape. Ya gotta know the part pretty well though and it's gotta be worth the time.

01-06-2009, 08:38 PM
I have had success bending and removing dents from pot metal using a heat gun and some wooden tools. Steel tools will mar the surface fairly easy when the pot metal is hot. Just be careful not to try to go too fast. Do NOT use a torch, because once it hit that special temp it will just liquify instantly!

01-06-2009, 09:42 PM
herers a related hint although not bending as follows have you ever wanted to weld a small pot metal or aluminum part back together ? ( if so) i had to do this this way
a few times a coupe times i welded those aluminum racks that pull the key to switch
wire found inside the GM tilt colums ... i did it by takeing a thin peice of steel and wraping or bending acurately to the the two halves of the broke part leave top area open ,then with the item placed as flat as levil is possible (proubably on a peice of wood) i use a propain
torch to play the flame onto the broken crack while holding a peice of aluminum rod in my ouher hand in about 20 - 30 seconds i can feed the rod into the now molten metal if you dont have aluminum rod find i thick peice of aluminum wire like painters us to hang that buckets on occasionaly or is sometimes used to tie chain link fence! the part will possibly be thicker and your tin should extend well beyound the area you r melting by inches or your part will melt away it might be posible to imbed a small part in plaster of paris let it dry a day then mend it outher wise forget my suggestion !

Crusty Nut
01-06-2009, 10:12 PM
As far as temp I would look into those temp sticks (like a crayon). Any welding shop should have them.

Mike Miller
01-06-2009, 10:50 PM
Boil it, I used to straighten scripts and such thet way.

12-23-2013, 11:32 PM
Small relief cuts on the back side and boiling worked great! Fitting Cadillac DeVille tail lights to the rear body on my '29 A. Bitchen tip.

12-24-2013, 08:45 AM
I need to take the slight curve out of these 39 Chevy trunk hinges to use as hood hinges. Been debating that or maybe flat filing them. What do you think?

12-24-2013, 09:33 AM
blowby, That is such a small, gentle bend I would put a wood block under the hinge pin and another under the tip and slowly bend it in a hydraulic press with a little heat from a heat gun. I might even try a wooden bending shoe in the press ram to conform to the general shape.
Post results.

12-24-2013, 09:33 AM
Pot metal will bend to a point, and then fractures. There's enough bent up pot metal grilles to show it will indeed bend. I had to straighten out numerous grille bars on my '46 Austin when I built it, and only a couple bars were fractured and needed to be fixed. The rest I was able to bend back into original position by gently working them a little bit.

12-24-2013, 01:25 PM
Rubber pad under them.

12-24-2013, 02:23 PM
Off topic, but 49-50 Fords have similar trunk hinges and they are quite straight on both sides might be worth finding some

Unkl Ian
12-24-2013, 03:33 PM
An Infrared Thermometer will handle the temperature reading.

12-24-2013, 04:29 PM
I've been beating on, welding and chroming pot metal for 40 years. No two pieces will react exactly the same. Some will seem soft and very compliant. Others are brittle and will break even if you heat them. I would warm it to just too hot to handle & tap it gently to see the reaction. Pot metal melts at 800 degrees, it heats real slow & then holds the heat, it doesn't change color and then you get a puddle on the floor. If your not a wham, bam kind of guy, take a 1/4 " plate & drill holes for the screw bosses to fit through. Tap or even use a C clamp to straighten.