brazing bodywork

[mperdue]

Any of you have experience with brazing body work? I just got some rust repair done and I noticed lots of brass brazing to fill in holes I assume. None of it is on the outside - just around the battery tray, firewall and lower door sills. Will POR-15 stick to this stuff, and does it need to prepped a special way? Does it offer any protection against rust of the underlying metal? I'm wondering if I got ripped on this repair work. Thanks,

Michael

[kmack]

Although, I've never done any brazing myself, I've seen lots of cars fixed using that method, including my 240. The dog legs had been repaired once before and at least the lower portions were brazed in place. It held well and still is. The bondo and paint stuck to it fine, so i would assume POR-15 to do the same. Just scuff it up good so it has something to stick to.

If I understand the process right, brazing is used when replace sheet metal sections because there is less chance of warping the surrounding metal and causing bad distortions in the panel.

[2ManyZs]

Brazing wouldn't be my first choice for attaching body panels, at least not unless it's done by someone who really knows what they are doing.

Brazing will only work if the base metal you are attaching together is heated with the torch, and usually it needs to be heated quite hot for the braze to hold. It's basically the same principle as soldering.

On thin sheetmetal, we all know what happens when too much heat is used. On some areas of the car it would be fine, other areas it could create a nightmare.:cross-eye

In areas that are not flat sheetmetal such as around the battery etc, it should work fine. Outer body panels for the most part it would be best to let only highly skilled people do it.

I've done a bit of brazing in the past on steel air tanks on tractor trailers where the mounting straps would hold moisture and the steel would end up with small rust pits that would leak air. Fairly thick steel, and you could use the braze to fill in the pits in the steel. A little too much heat and you burned a hole in the tank, not enough and the braze just sat on top of the steel and blew off under air pressure.

[mperdue]

Thanks for the help. I've also spoken to someone locally who knows this stuff and he thinks it looks good. The important parts are welded and the brazing is just there for clean-up.