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Technical Brazed on body panel, should I remove the braze?

Discussion in 'The Hokey Ass Message Board' started by Mopar Tony, Jun 21, 2020.

  1. Mopar Tony
    Joined: Jun 11, 2019
    Posts: 563

    Mopar Tony
    Member

    I just bought a 1950 mercury which I am super excited about but after doing some thorough examination I realized it has had a ton of things brazed on. The rocker panels being one of them and it concerns me. Is that strong enough? Should I grind all of it off and weld the panels in? The car was primered and blocked 6 years ago but never got paint and I will need to re-prime and do some more body work. Any advice with what I should do? I was told body filler doesn't stick to braze long.
     
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  2. squirrel
    Joined: Sep 23, 2004
    Posts: 56,042

    squirrel
    Member

    It should be plenty strong. What you might want to consider is how well the brazed joints were cleaned and prepped after they were brazed. If all the flux was removed, and the brass was sanded/ground to give it some "bite", then it will probably be fine.

    Is there any evidence of cracking or bubbling in the filler or primer? It's been on there six years....
     
  3. chopolds
    Joined: Oct 22, 2001
    Posts: 6,214

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

    When I first learned to do customizing, I learned with brass (1979) Did it for quite a few years, before I bought a MIG. I built my whole chopped Olds with brazing, except for the lake pipes., and it still looks good after almost 40 years. the secret is cleanliness. With today's materials, you could even separate the brazing from the filler work, with a couple coats of epoxy. Strength is not an issue. I've had to cut out brazing on my current project, a 56 Olds converted to Nomad style wagon, that was actually done by the guy who taught me. But the reason was that he must have been getting older, or lazier, and he did a lot of it by overlapping new metal over the old, whether rusted out parts, or trim holes. The overlapped pieces were the trouble one. Dirt/water gets trapped between them and prematurely rust the panels out. Look for this on your car. Much more problematic than just brazing.
    Oh, other ways to get around it...either use lead filler instead of plastic, or just do a "tinning coat" of solder to cover the brass, before doing epoxy or plastic filler. But if you just clean it thoroughly, you shouldn't have a problem.
     
  4. Mopar Tony
    Joined: Jun 11, 2019
    Posts: 563

    Mopar Tony
    Member

    From what I can see there is no cracking or bubbling but I will have to look closer. I drove 7 hours to get it and 7 hours back. When I was there I looked it over quick and that is when I noticed the brazed parts, the seller didn't tell me about that part obviously. But after the drive and the fact I have been wanting a merc since childhood I picked it up for 1500 bucks. I'll have to go over it with a fine tooth comb but so far I don't see anything too alarming. There are a couple spots where the guy ground some off and put a hole in the metal. He said he got it that way too and was a old body mans car back in the day. So my guess is that some of these repairs are many many years old. The rocker panels look pretty recent and done well, but still with braze.
     
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  5. Mopar Tony
    Joined: Jun 11, 2019
    Posts: 563

    Mopar Tony
    Member

    I am afraid of the rust but also was told that filler doesn't like to stick to it so I am a little afraid of it. I have no idea how to lead or tin anything LOL.
     
  6. partsdawg
    Joined: Feb 12, 2006
    Posts: 3,507

    partsdawg
    ALLIANCE MEMBER
    from Minnesota

    Read any of the old little car magazines and they are filled with 'how to' articles that feature brazing. MIGS and TIGS were years away from being the norm. I wouldn't worry about it.
     
  7. On old time brazing flux left behind is the problem.It flows in to cracks,and looks like glass.First time it gets moist it turns to a white powder that lifts the primer. You could blast the braze area with a medium like walnut shell to clean it.Replacing with welding is a problem since any brass left will contaminate the steel making it impossible to weld. Watch a utube video on leading/ tinning. Gene Winfield himself has one on there.You just need a thin plating of lead to turn it silver.Being very clean is the ticket to good flow.Eastwood compamy makes a tinning compound that makes it much easier.Use clean fine steel wool to move the tinning while hot. Now a days MIG brazing is used a lot on thinner modern car steel.No flux left behind.
     
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  8. Nothing wrong with brazing,,,,,it’s how things were done at one time,,,,and,,,it’s very strong .

    Tommy
     
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  9. mickeyc
    Joined: Jul 8, 2008
    Posts: 1,368

    mickeyc
    Member

     
  10. lostone
    Joined: Oct 13, 2013
    Posts: 2,857

    lostone
    Member
    from kansas

    I agree with the above. Years ago the mig was not available so just about any car, hot rod, custom or stock that had any kind of panel repair would have been done with brazing.

    I know a couple old timers that still prefer doing it.

    Also like said above, the only problem is cleaning. I would guess that if its been a minimum of 6 yrs since the brazing on the car and your finding zero problems that who ever did the work knew what they were doing.
     
    irishsteve likes this.
  11. sunbeam
    Joined: Oct 22, 2010
    Posts: 6,219

    sunbeam
    Member

    Like others have said it is the flux that caused the problem
     
  12. Mopar Tony
    Joined: Jun 11, 2019
    Posts: 563

    Mopar Tony
    Member

    So just try and clean it up to make sure it isn't contaminated and work filler over it?
     
  13. chopolds
    Joined: Oct 22, 2001
    Posts: 6,214

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

    If at all worried about it, put a coat of epoxy primer on it first. You can put filler over epoxy.
     
  14. 49ratfink
    Joined: Feb 8, 2004
    Posts: 18,847

    49ratfink
    Member
    from California

    I would remove it all and weld everything in if I ever planed on having a quality paint job done and wanted to keep it for the long term. braze and bodywork can do strange things after time.

    did a bunch of rust repair on a 64 Impala that had been customized in the 80's. all the trim holes were brazed and all the trim holes were now visible in the paint. door handles, key hole, everything done had failed.
     
  15. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,659

    Rusty O'Toole
    Member

    Nothing wrong with brazing. Millions of cars were repaired that way, and believe it or not the factory brazed some seams. As long as there are no pin holes to let moisture through from behind, and as long as you get all the flux off . Get a good trouble light and get your nose down a few inches from the seam and inspect it carefully. Any gaps can be brazed or plugged with seam sealer. Flux can be ground off or cleaned off with a wire wheel or wire brush in a drill or by sandblasting. If the seam is clean and solid apply filler in the usual way and it will last.

    As an aside, WW2 era airplanes had engine bearers and other parts made of chrome moly tubing butted and brazed together. Schwinn's best and most expensive bicycles were hand made the same way, of chrome moly butted and brazed. That is their racing bikes, Super Sports and Paramount models. Brazing does not cause brittleness the way welding does on chrome moly. If brazed joints held a 2000HP engine in a fighter plane they will hold the rocker panel on a Mercury.
     
    Last edited: Jun 22, 2020
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  16. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,659

    Rusty O'Toole
    Member

    You can't weld over braze and it is practically impossible to get all the braze off. If you really have a bug up your ass about brazed joints you will have to cut out all the brazed parts and start over from scratch. I strongly recommend you NOT do this, clean up the joints, make sure they are sound and free of flux and you are good.
     
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  17. High end steel road and mountain bicycles are still brazed. They get finished and painted just like our hotrods and customs. No issue with the brass and paint. Plenty strong. Listen to Chopolds[​IMG]
     
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  18. wheeldog57
    Joined: Dec 6, 2013
    Posts: 3,173

    wheeldog57
    Member

    Years ago I bought used quarter panels for the 57
    One side had a brazed panel put in and the other side needed a patch which I fabbed up and MIG welded it in. I thoroughly sanded and cleaned the brazed side. I then did body work over the whole car. Guess which patch bubbled up after 9 years. . . . ? Welded side
     
  19. Beanscoot
    Joined: May 14, 2008
    Posts: 3,075

    Beanscoot
    Member

    Nice picture of well done brazing, Tman.
    Maybe we need a thread titled "Show us your beautiful brazing"!
     
  20. 31Apickup
    Joined: Nov 8, 2005
    Posts: 3,378

    31Apickup
    Member

    I have some brazed on patch panels we did in the late 70’s which have held up well. Cleaned the braze well and then sandblasted them. I wouldn’t braze something now. If cleaned well and epoxy primed prior to filler they should be fine.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  21. goldmountain
    Joined: Jun 12, 2016
    Posts: 4,466

    goldmountain

    Lately, I have started watching "Brittania Motorcycles" on YouTube and Michael Waller explained about the joints on motorcycle frames and now I'm back to brazing some things I'm working on.

    Sent from my SM-T350 using The H.A.M.B. mobile app
     
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  22. squirrel
    Joined: Sep 23, 2004
    Posts: 56,042

    squirrel
    Member

    Have you ever seen an original Model T oil pan, without it's paint? This is what they look like. The brazing sealed the rivets, and strengthened the mounting points.

    IMG_20200610_100101522.jpg
     
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  23. KenC
    Joined: Sep 14, 2006
    Posts: 1,050

    KenC
    Member

    One thing that is often overlooked: Most brazing fluxes are water soluble. So, lots of water, hot if possible and a scrub with a brush ( I like the little brass or stainless ones that look like a toothbrush) will remove the residue very easily. One caution though, do not overheat the flux as it will become black, hard and won't wash off.

    As others said, the only issue with brazing is not cleaning the flux off well. Primers, fillers and paint will adhere to clean brass just fine. And it is more than strong enough for body work.
     
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  24. Beanscoot
    Joined: May 14, 2008
    Posts: 3,075

    Beanscoot
    Member

    I had noticed the brazing on a model T oil pan in the junk pile at the old homestead, but assumed it was later repair.

    But a model T oil pan way back then would never get a chance to see water with its thick coating of oil and dirt.
     
  25. loudbang
    Joined: Jul 23, 2013
    Posts: 40,292

    loudbang
    Member

    Think of brazing this way...................... it is still to this day the method used by ROLLS ROYCE to attach the sail plain quarter panel section to the roof. Well if it's good enough for ROLLS ROYCE I would think it's ok on your car. :rolleyes:
     
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  26. Thats David Kirks work. He is from Montana and is also a car guy.
     
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  27. cabriolethiboy
    Joined: Jun 16, 2002
    Posts: 891

    cabriolethiboy
    Member

    The old body men used to tell me that paint would not stick to brass very well and you need to sandblast it before you prime it. So I have always welded, sure would have been easier to braze some of them.
     
  28. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,659

    Rusty O'Toole
    Member

    It's the flux not the bronze. Get the bronze clean and paint, lead or body filler sticks to it just fine.
     
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  29. Gearhead Graphics
    Joined: Oct 4, 2008
    Posts: 3,890

    Gearhead Graphics
    Member
    from Denver Co

    my 57 had bronzed on repairs, and 3/4 to 1 1/2 inches of bondo over some. They had to do something before MIG came out. as said by many, if its a solid repair clean it up and go with it
     
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