Date:         Tue, 23 Mar 2010 14:01:47 -0700
Reply-To:     Robert Keezer <warmerwagen@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Keezer <warmerwagen@YAHOO.COM>
Subject:      Re: Solder cracked steel coolant pipe?
In-Reply-To:  <4ba9157f.16115e0a.672f.ffffc321@mx.google.com>
Content-Type: text/plain; charset=iso-8859-1

 Dave-that sounds better than just filling the crack. I'll have my friend drill the two holes you suggested and make a patch. That makes more sense .
It needs to be good as this is above the gas tank- making tank removal nesscary again if it fails. 
I can't risk having it fail on a test run or after I sell it. 
My other idea was to cutr the pipe off aft of the tank, bring it to be welded, then reinstall with a section of rubber hose to couple them. 
 
That way the tank doesn't need removing again.
 
If there was a Vanagon at my local yard I woul have got a used pipe already, maybe the plastic ones. But I have already had the Van 3 years and I have to sell it by May . I donb't have the time to add any more time to it- I stll have to change the pop-top canvas and seal etc. 

--- On Tue, 3/23/10, David Beierl <dbeierl@attglobal.net> wrote:


From: David Beierl <dbeierl@attglobal.net>
Subject: Re: Solder cracked steel coolant pipe?
To: "Robert Keezer" <warmerwagen@YAHOO.COM>
Cc: vanagon@GERRY.VANAGON.COM
Date: Tuesday, March 23, 2010, 12:19 PM


At 12:53 PM 3/23/2010, Robert Keezer wrote:
> Ok- So I have a  friend who came over yesterday and soldered a one inch crack in one of the steel coolant pipes which cracked above the gas tank.
> I don't trust it, but he persuaded me.

Dear Robert,

I don't either.  Whatever stress split the pipe may still be operating and a soft-solder butt joint has very little strength.

If the split is along the length of the pipe I would recommend either brazing (which may be difficult now that there's solder there) or making a patch that fits the curve and extends a half inch or more beyond the split on the sides and an inch or more on the ends.  I would form this closely to the curve of the pipe.

I would drill a hole -- 3/16 or 1/4 -- at each end of the crack to give stress relief.

I would then polish the pipe shiny bright in the patch area and tin it using plumber's solder and plumber's flux (OR some strong and fancy low-temp solder from jeweler's supply house; I think the brand is Tix and the price is $$$).  Likewise shine up and tin the interior of the patch, and butter it lightly with flux.

Put the patch in place and apply light pressure.  Heat the whole with a torch until the solder liquefies and the patch settles into place.  Move the torch around and don't let things get red hot.  Feed more solder around the edges until it stops accepting it, then let it cool.

I would expect that to last a very long time.

But if the split is around the circumference of the pipe, I think a soft-solder patch would not be strong enough, and you would have to clean it up and braze a patch on.  The three common brazing metals are "bronze," "nickel silver" and actual silver which can be had in several melting points.  Any of them should work but the silver is easiest.  Airco or other welding supply house and ask for the proper flux even if the rods are flux-coated.  If you get low-melting silver, make sure it does not have cadmium in it.  A propane-air torch should be able to reach the necessary temperature and a Mapp-gas torch might.  An oxy-acetylene torch definitely will.

An alternative would be to cut the pipe at the split and rejoin it with a piece of 1.5" ID heater hose, silicone by choice (truck-supply place).  In van terms I would expect that to be "permanent" and it would relieve any stress in that area.

Yours,
David