making a mild steel plate convex

[Steve Bunyard]

I'm working on a project in which I have an 1/8 inch oval shaped steel plate that I need to put a slight convexity in from top to bottom and left to right. Don't have any special equipment though except a press. Any ideas?

[Showdog75]

You need to find someone with a heavy duty english wheel.

[kraythe]

I'm working on a project in which I have an 1/8 inch oval shaped steel plate that I need to put a slight convexity in from top to bottom and left to right. Don't have any special equipment though except a press. Any ideas?

Heat the center with an oxytorch until it is cherry red then use a sponge full of water and cool it rapidly. This will cause the plate to bend. The metal where it is cooled rapidly shrinks, drawing in the sides. Repeat until you get the proper bend.

[4sfed]

I'm working on a project in which I have an 1/8 inch oval shaped steel plate that I need to put a slight convexity in from top to bottom and left to right. Don't have any special equipment though except a press. Any ideas?

An English wheel would be ideal as long as there's no scale on your material . . . unless the anvil (small wheel) is hardened. Are you near Dayton, OH?

How smooth / consistent does the surface need to be? You could also hammer the center of the plate against a hard surface, lots of small hits. That will thin the material, making it expand in length. Since the outside is constrained, the center will bow and create the concave surface you want. A torch will also work, but you need to shrink the outside of the plate, not the inside, or you will just cause it to buckle.

Jim

[crawdaddy]

How about putting it on a shot or sand bag and hammering to get the shape you want? Mike

[Chuck U&R]

Grind the shape you want into a stump - like a bowl.

Place steel over the whole, hit with hammer, repeat...........

[Sonora Iron]

How about putting it on a shot or sand bag and hammering to get the shape you want? Mike

I’ve seen this done, amazing what some people can do with a wood / rubber / rawhide mallet, and a sand bag. Oh and a lot of patience!

[kraythe]

I’ve seen this done, amazing what some people can do with a wood / rubber / rawhide mallet, and a sand bag. Oh and a lot of patience!

I think it would depend on the thickness of the plate. For 1/8th it would work. For 1 inch, no chance.

[Sonora Iron]

For 1 inch, no chance.

Just get a bigger hammer!

http://www.ent.ohiou.edu/~raub/manuf...ng/forging.htm

[Showdog75]

How about putting it on a shot or sand bag and hammering to get the shape you want? Mike

1/8" steel is difficult to hammer form. Give it a shot sometime.