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donemoto
Samba Member
Joined: March 01, 2004
Posts: 501
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 Posted: Thu Aug 21, 2008 8:19 pm Post subject: Heater box repair |
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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.  
_________________
1975 Campmobile
1962 Bug Convertible
Homebuilt VW Trike
1966 HD Sprint H
1940 HD ULH Flathead
1985 Electra-glide Classic with Tour-Pac
1968 Harley Rapido
1968 Honda CL Scrambler 175cc
1962 Honda Cub 50 Step-thru
1980 Honda Cub 70 |
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donemoto
Samba Member
Joined: March 01, 2004
Posts: 501
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| Posted: Thu Aug 21, 2008 8:24 pm Post subject: |
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Missing pic of Foundry Blanket . 
Filling in the voids.
_________________
1975 Campmobile
1962 Bug Convertible
Homebuilt VW Trike
1966 HD Sprint H
1940 HD ULH Flathead
1985 Electra-glide Classic with Tour-Pac
1968 Harley Rapido
1968 Honda CL Scrambler 175cc
1962 Honda Cub 50 Step-thru
1980 Honda Cub 70 |
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Hippopotabus
Samba Member
Joined: May 27, 2004
Posts: 1600
Location: Miwuk Village, CA
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| Posted: Thu Aug 21, 2008 9:15 pm Post subject: |
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Dude very nice!!!
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Celer, Silens, Letalis
www.2dreconbn.net |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 52924
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Thu Aug 21, 2008 9:33 pm Post subject: |
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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.
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Rust NEVER sleeps and stock never goes out of style.
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donemoto
Samba Member
Joined: March 01, 2004
Posts: 501
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| Posted: Fri Aug 22, 2008 4:15 am Post subject: |
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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.
_________________
1975 Campmobile
1962 Bug Convertible
Homebuilt VW Trike
1966 HD Sprint H
1940 HD ULH Flathead
1985 Electra-glide Classic with Tour-Pac
1968 Harley Rapido
1968 Honda CL Scrambler 175cc
1962 Honda Cub 50 Step-thru
1980 Honda Cub 70 |
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Dogman
Samba Member
Joined: July 11, 2008
Posts: 109
Location: Boise, ID
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| Posted: Fri Aug 22, 2008 8:06 am Post subject: |
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Nice work! I thought the foundry blanket could be seen in the left side of this picture 
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'73 Riviera | 1700cc | Dual Dellorto 34b FRD | 009 |
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Opossum
Samba Member
Joined: February 26, 2005
Posts: 760
Location: Islets of Langerhans
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| Posted: Fri Aug 22, 2008 8:42 am Post subject: |
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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?
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"You can lead an aircooled to water, but you can't make it drink"
"Live and learn or crash and burn"
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Virginia Whiteface (Opossum) the first VW
Camper Special Club Member
1973 Orange Westfalia Hard top, Original owner |
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rustybutterknife
Samba Member
Joined: June 06, 2003
Posts: 488
Location: Georgetown, IN
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| Posted: Fri Aug 22, 2008 9:20 am Post subject: |
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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.
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What, they don't sell purple locktite? Just mix the red and the blue together. |
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hiwaycallin
Samba Member
Joined: May 07, 2008
Posts: 362
Location: Salmon Arm, BC
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| Posted: Fri Aug 22, 2008 9:31 am Post subject: |
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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 ...  |
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DesignGentry
Samba Member
Joined: January 16, 2011
Posts: 20
Location: Oregon
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| Posted: Sat Apr 23, 2011 9:08 pm Post subject: |
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I know it's an old thread, but was really wondering how these held up over time(particularly where the heater box meets the exhaust tubes?
Did the JBWeld withstand the heat there? |
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ccpalmer
Samba Member
Joined: September 17, 2006
Posts: 3851
Location: Ann Arbor, Michigan
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| Posted: Sat Apr 23, 2011 10:37 pm Post subject: |
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| DesignGentry wrote: |
I know it's an old thread, but was really wondering how these held up over time(particularly where the heater box meets the exhaust tubes?
Did the JBWeld withstand the heat there? |
I'm gonna guess no..
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levi20AE
Samba Member
Joined: June 24, 2005
Posts: 485
Location: Las Vegas, NV
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| Posted: Fri Oct 10, 2014 1:51 pm Post subject: |
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I have some heater boxes that could use some loving before being installed back in the bus. Does anyone have any info on how to braze or solder repair the small areas that are missing material? Its not a lot of area but i would rather do this job now then next year when the material is too far gone to repair without replacing sheet metal.
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20th AE VW GTI - 369hp 340tq @ 26 PSI
1982 Rabbit Pickup - German AAZ 1.9TD - daily with lots of MPGs |
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tootype2crazy
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Joined: October 08, 2007
Posts: 1276
Location: St. Louis Missouri
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52486
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| Posted: Fri Oct 10, 2014 7:18 pm Post subject: |
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| Make sure your boxes are worth salvaging before going to all the trouble to repair the covers. The flanges where the boxes bolt to the heads thin with age causing sealing problems (you can build them back up with some careful welding and grinding) and the various flanges thin and get too flimsy to seal and the pipes where they attach to the flanges can burn/rust through. |
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WhirledTraveller
Samba Member
Joined: January 09, 2008
Posts: 1414
Location: Cambridge, MA
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| Posted: Sat Oct 11, 2014 8:58 am Post subject: |
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| DesignGentry wrote: |
I know it's an old thread, but was really wondering how these held up over time(particularly where the heater box meets the exhaust tubes?
Did the JBWeld withstand the heat there? |
I think I can answer the question since I did something similar with JB Weld on my '77 style heater boxes 5 years ago. They weren't as bad as the ones in this thread, I was just trying to seal them up for a bit and get a few more years out of them.
The JB Weld helped... and I think it lasted a year or maybe two. But now 5 years and 15,000 miles later the JB Weld is basically all gone, it cracked and flaked off.
In addition the POR15 paint I used all came off the hottest areas.
If you want to really make these things last, you need to pony up for proper metal repair and ceramic coating.
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1977 Westy, Automatic. Big Valve heads, CS Cam. |
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Savybosh
Samba Member
Joined: February 26, 2011
Posts: 3
Location: Houston
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| Posted: Mon Mar 09, 2015 7:41 am Post subject: Heat exchanger tin, joint repair. |
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Quick Steel makes a High Temp putty. You can work it easier into the bigger crack and smooth it out too so it looks nice. Then spray Flameproof Exhaust paint over it all. (AutoZone)
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eche_bus
Samba Member
Joined: October 07, 2007
Posts: 1318
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| Posted: Mon Mar 09, 2015 1:33 pm Post subject: |
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A few related questions:
How tight of a fit was there between the pipes and the housing tin when these exchangers were new? Was the housing weld-sealed to the pipes or crimped tightly against it or ?? In other words, how good of a seal is really necessary?
My concern with using putty/JB-weld is that the pipes, putty, and housing tin all have different coefficients of expansion. It seems with repeated heatup/cooldown this would just sort of crack apart? Not true? |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 52924
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Mon Mar 09, 2015 1:43 pm Post subject: |
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| eche_bus wrote: |
| My concern with using putty/JB-weld is that the pipes, putty, and housing tin all have different coefficients of expansion. It seems with repeated heatup/cooldown this would just sort of crack apart? Not true? |
Mine too, all that stuff grows at a different rate.
The OG ones were tight to the pipes but not attached so there was still room to slip, it'll be interesting to see how that job looks in a few years.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52486
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| Posted: Mon Mar 09, 2015 3:00 pm Post subject: |
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| busdaddy wrote: |
| eche_bus wrote: |
| My concern with using putty/JB-weld is that the pipes, putty, and housing tin all have different coefficients of expansion. It seems with repeated heatup/cooldown this would just sort of crack apart? Not true? |
Mine too, all that stuff grows at a different rate.
The OG ones were tight to the pipes but not attached so there was still room to slip, it'll be interesting to see how that job looks in a few years. |
Maybe wrapping the pipe with a layer of masking tape before applying the putty would be the way to go. |
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airschooled
Air-Schooled
Joined: April 04, 2012
Posts: 13536
Location: West Coast, USA
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| Posted: Mon Mar 09, 2015 3:35 pm Post subject: |
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| busdaddy wrote: |
| eche_bus wrote: |
| My concern with using putty/JB-weld is that the pipes, putty, and housing tin all have different coefficients of expansion. It seems with repeated heatup/cooldown this would just sort of crack apart? Not true? |
Mine too, all that stuff grows at a different rate.
The OG ones were tight to the pipes but not attached so there was still room to slip, it'll be interesting to see how that job looks in a few years. |
I have used the "high heat" muffler putty on my T1 rear "kidney" heat exchangers with good results. They didn't line up when I bought the muffler, so I ripped them apart at the seam and used the stuff to seal all the heat exchanger seams. It's not on the hottest part of the muffler, but it is doing great 2-3 inches from the exhaust port on the head.
Robbie
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