TheSamba.com :: View topic

Thu Aug 21, 2008 8:19 pm

In the middle of my backyard rebuild, I had to change the heads, which meant I to to also change the heater-boxes and muffler.

The heads I am using are 1979 one year only.
I priced replacement heater-boxes at $400 each plus $169 for header exhaust.

After searching Samba adds; I found none. Going into the Junkyards still nothing. I went down into my basement and got a pair of 79 heater-boxes that I pulled off a Bus in 1996 after dragging it out of a neighbor's field. These, then, will be the ones I will repair.

Lets start....
Textbook heater-box damage from years in the snowbelt.

This box is the worst. It will have to have the rust cut out and a new patch panel welded in.

Donor heater-box (a 1983 Vanagon) is sectioned by using a side grinder.

After tin patch is clened up on bench grinder it layed out on heater-box for fit-up.

Some of you can see that donor was a lefty while box is a righty. Since hole distance between header pipes are the same on all; the patch will work.
Heater-box patch panel has been tack welded in place, hammered and peened to fit tight, stitch welded, and buttered with 2 sealing coats of JB Weld.

Next up is packing and repairing the damage around exhaust tubes. I use Foundry cloth to fill in void or cavity left by rust. Tear pieces of foundry blanket about 1" bigger than cavity.
This is a pic of patching material. A section of Foundry Blanket. It is non-asbestos fire-proof packing used in Foundry procedures. I have plenty of this available. PM me if U need some.

Pack it in with a screwdriver until about 3/16" shy of top. This will serve 2 purposes: 1) To fill and insulate tin...2) allow for a makeshift armature for JB Weld to adhere to...

Spread JB Weld on both heater-boxes at same time to use up batch. I used 2 coats just to be on the safe side.

After set-up time overnight, go back and check for voids (holes from the new patch). Skim them now.

Left heater-box finished and painted.

That's it. Will it work? I think so. Looking for another 4 or 5 years out of these. J B Weld should work in the heat range of these boxes under load.

Cost : about $30.00. One can of high heat Rustoleum Spray paint, 4 tubes of JB Weld a little fabbing and welding time.

Will show pic of finished right heater-box manyanna if anyone want to peek at it.
There U go my little hippie prospects...one low budget project for ya. 8) :)

Thu Aug 21, 2008 8:24 pm

Missing pic of Foundry Blanket . :oops:

Filling in the voids.

Thu Aug 21, 2008 9:15 pm

Dude very nice!!!

Thu Aug 21, 2008 9:33 pm

I've done similar resurrections but used brass rod and brazed the repairs in, please keep us updated on the longevity of the JB weld.

Looks way better than the before pics, nice work.

Fri Aug 22, 2008 4:15 am

These boxes were way to gone to put a torch on them for brass-work.
As you know a gas torch will eat up rusty metal. That's why I used a cold weld process. Welding the patch panel, I had to turn my TIG machine down to 40 to keep from burning thru.

Fri Aug 22, 2008 8:06 am

Nice work! I thought the foundry blanket could be seen in the left side of this picture :lol:

Fri Aug 22, 2008 8:42 am

From the JB Weld website:

Q: How much heat can J-B Weld withstand?
A: J-B Weld (Part # 8265-S, 8265, and 8280) can withstand a constant temperature of 500 degrees F. The maximum temperature threshold is approximately 600 degrees F for a short term (10 minutes).

Q: Will J-B Weld work on an automotive exhaust?
A: Because of the extreme temperatures of exhaust systems, we do not recommend J-B Weld for use on exhaust manifolds and catalytic converters. Nor do we recommend the product for repairs within the combustion chamber.

How hot does an exchanger get?

Fri Aug 22, 2008 9:20 am

From ratwell's site. My best guess would be an average 600 deg. considering that the manifolds are part of the heat exchangers. Might be as low as 300 leaving the exchangers but I wouldn't think it'd be much lower than that.

Fri Aug 22, 2008 9:31 am

Awesome thread! Mine need some work but not nearly as much as what you started with. I think I can do it! I think I can ... I think I can ... :lol: :D :lol: :D