Date:         Fri, 1 Oct 2004 01:33:40 EDT
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: Home Made Bull Bars--Pipe Benders Not Needed
Content-Type: text/plain; charset="US-ASCII"

In a message dated 9/30/04 11:51:36 AM, john@AIRCOOLED.NET writes:

<< you don't want a tubing bender, you want a mandrel tubing bender. >>

. . . or mandrel bends.

It escapes me why you want anything so bump ugly but if you want to roll your
own here are some things to consider:

Tubing -
Tubing is available as hydraulic tubing or mechanical tubing in mild steel,
alloy steel or stainless with various wall thickness.  Pre-formed mandrel bends
are also available.  Fab the bumper from the tubing of your choice using
factory mandrel bends for the returns on the ends and for whatever else strikes
your fancy.

If you have trouble finding the bends or tubing, talk to a fab shop which
specializes in handrails; they use mandrel bends by the truckload.

If you want to do bends without a bender, you can use an oxyacetylene torch.
Ask your welder if he is familiar with the term "wrinkle bending".  It is a
hot pipe bending technique used in the old days whenever pipefitters actually
made the fittings they needed.  The inside radius of the bend ends up with a
series of evenly sized and spaced wrinkles.  The nice thing is that a wrinkle
bend does not thin the wall thickness nor reduce the cross-sectional area of the
pipe.  Fab the bumpers using wrinkle bends then hide the bends behind a
"shadow package" (diamond plate top and sheet steel facing).

If you bow the bumper to match the gentle curve of the Vanagon's nose and
tail, it should look even better than what you can buy.

Pipe-
Now, if I wanted a bull bumper, I would make it from Schedule 10 stainless
pipe.  At 0.120" the wall thickness is only 0.025" greater than the mild steel
offerings of the bull bumper builders and the OD of 2 1/2 inch pipe is about
2.875" or nearly 3 inches.  Nice tight radius butt weld fittings are readily
available.  The cost of type 304 stainless would not be astronomical as long as
you didn't buy polished pipe and fittings.  The down side is that if you want a
high polish you either have to spend the bucks or plan on spending some
quality time with flap wheels and Scotchbrite wheels.  I'm sitting here looking at
a 1 1/2" Sched 10 ell and nowadays the finish on them is not that rough, it
looks evenly stippled.  If I were to make a bumper of the stuff, I would leave
the mill finish on it and I would not grind the welds as long as the welder
knew his craft; a PROPERLY executed TIG weld is a thing of beauty.

I just have to say this: there are far more elegant ways to fabricate a macho
bumper for a Vanagon.  A bull bumper is just the result of a couple of
shitkickers needing a bumper and having an old corral gate behind the barn.  The few
attributes of a bull bumper are that they can be produced cheaply, easily and
with no thought to design.

George