Bodywork, Paint, Interior, Trim, & Wiring

discussions about bodywork, paint, interiors, trim, audio, electrical components, wiring, etc.

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rficalora
Rob Ficalora
Willis, TX
(2694 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Nerf bars
Posted by: rficalora
Date: December 11, 2008 11:23PM

I'm thinking about making some nerf bars for the rear on my car... found some mild steel balls that I can get in 3/4" or 1" that can be welded to the ends... but can't think of a good way to bend the steel bar to match the profile of the sebring rear valance. How would you do it?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5965 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

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Re: Nerf bars
Posted by: BlownMGB-V8
Date: December 12, 2008 09:07AM

Heat it? Or a hydraulic press, or a couple of long pieces of pipe, or... There have to be literally dozens of ways but it really depends on what you have to work with.

Jim


Moderator
Curtis Jacobson
Portland Oregon
(4478 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

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Re: Nerf bars
Posted by: Moderator
Date: December 12, 2008 10:11AM

Leverage is your friend. The bends will be much easier to make if you bend longer sections and then trim them. Consider slipping a larger size of pipe over the material you're bending to reinforce areas you don't want to bend. Buy enough raw material in the first place that you can make practice bends and mistakes...


rficalora
Rob Ficalora
Willis, TX
(2694 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Nerf bars
Posted by: rficalora
Date: December 12, 2008 06:26PM

I assumed heating & bending... hadn't considered the larger size to keep the parts i don't want bent straight, that's a good suggestion. The sebring valance has about a 3" radius curve at the edge, but then it tapers down at an angle. If I do this I want it to mirror that shape... I'm thinking maybe I can bend it over a plywood form or something like that... i'm going to play with some forms -- it's not urgent that I do this... just that I decide if i'm going to because I'd want to cut the slots in the valance before I get the car painted & I'm getting closer every day.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5965 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Nerf bars
Posted by: BlownMGB-V8
Date: December 12, 2008 07:58PM

Plywood forms are OK, but are best used as templates to check the bend rather than as mandrels to bend around. If you want a mandrel the proper way is to use plate (1/4" would likely work here) figure the spring back of the material (may require testing) subtract that and one material thickness from the desired radius and cut out a curved section of that radius. Add enough to the required length of arc to account for the springback and a little more. Cut a strip of the same material a little wider than the round stock, shape and weld it to the arc section to form a curved mandrel. Anchor that to something substantial. A bending floor is wonderful but who has one of those? There's only one place I know of and that's closer to Jake's neighborhood. Hjorth Bros. in Mapleton. Anyway, if it means that much, you could sink a couple large anchors in the garage floor, but I'd say if cold bending (advisable on concrete) they should be 3/4" or better. (A large base plate will let you get by with lighter bolts, and allow some heat.) Anchor one end to the mandrel (an extension or socket on the mandrel is a nice touch) and pull the other end around the mandrel with a come-along or winch attached to another strategically located anchor. This one could be a 3/8" bolt due to the leverage. Use a pipe if desired to preserve the straight section, a couple feet of it would be enough but be careful. If you bend the pipe it's back to square one. Depending on your length of arc you might have to strategically locate a snatch block at one or more alternate anchor points to bend the full arc.

That's the lowdown on how the pro's do the big stuff. It works on a smaller scale too.

Jim


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