Vanagon – rear bumper build

I figured I need to post what I have done so that I have more reason to finish the job. I want to make new bumper, front and rear. Not because the stock bumpers are damaged or rusty, but because I want bumpers that are a bit stronger and will be able accept a spare tire carrier on the rear and better aux. light mounts up front. And just because I want to make some bumpers.

It’s a project that never seems to get really going nut here is the progress to date.

Last year I fooled around with making a mock up rear bumper out of door skin and hot glue. I came up with a shape that to be honest was the best I could given the brief of it being simple, slim (not bulky like some aftermarket bumpers – yes, I’m looking at you Go-Westy) and easy to make. The door skin and hot glue construction makes it easy to add or remove material and have a relatively solid model to play with. I have a hard time visualizing an object from drawings so I tend to make a mock up (or remake the real object).

I started with a slim bumper design, very simple with a flat top surface (to make standing on bumper easier), a gentle curve on the rear vertical face that closely mimics the stock bumper, and a curved lower edge rather than straight lines to where the bumper caps would be. I took the first design over to let Simon have a look. His tastes lean a bit more towards a heavier bumper so I stuck on more door skin and made it so.

BTW, in the mock up pics the bumper is shifted to the left due to interference between the stock bumper mounts and some wooden braces in the mockup.

I don’t like this at all.

I removed some wood, looks better. Probably would please Simon.

But I like ’em slimmer still. Ended up back to the original shape.

Right then, I’ve settled on the rough shape now what material will the real bumper be made from? Silly question, aluminum naturally. I’m using some off-cuts of 1/4″ aluminum plate (6061). I think that thickness will be plenty strong, especially when it is bent and welded up into the final “C” channel of the design.

I should mention that I took dimensions from the mock up and “projected” the 3 faces onto the top of the workbench. I used a bit of wood to fair the curves and picked up the shapes for the 3 main parts (top, bottom, rear face)h onto some polyethylene sheet. I could then tape the pattern onto the aluminum stock and use a prick punch to mark the shape on the aluminum. But I’m getting ahead of myself, I have to weld some of the aluminum together before cutting out the shapes.

My lumpy and large TIG weld. In my defence, I hadn’t touched the welder for a couple of months so what little skill I did have seemed to have slipped away.

I’ve cut out the 3 main parts, rather roughly I’m afraid, and if I have time today I’ll try bending and tacking them up. I’ll need to make some internal braces just to make the weld up easier. I’ll TIG weld the tacks, then I think I’ll use the MIG welder for the final weld up. It would be sort of silly for me to TIG the long welds.