Rad Cowl repair

[Erich]

As a neophyte with body repair that must be plated, I have a question. My radiator cowl is dented. I know that straightening will not eliminate all the dent. So now in the day when body lead here in the US seems to be made of Unobtanium, is there a filler that can be effectively chromed?

Erich in Seattle

[Charles P]

Silver solder. Not soft solder.

[Duncan Grimmond]

As long as there has been no use of soft (lead or lead free) solder or lead filler there is no reason that dents should not be removable as long as there is 75-80% thickness. It is possible to anneal locally with oxygen/propane or acetylene and carefully tap out the dents with a hardwood mallet on a steel stake.
If the metal is very thin a patch can be silver-soldered into a cleanly cut out area. a good fit is essential as the silver solder depends on capillary action to run into the join and maintain the strength of the piece. Cleanliness and a good fit are absolutely critical.
There are instructional videos on Youtube...
Don't use lead as a body filler, it will make the part unrestorable as even the smallest remaining bit of lead will eat its way through the brass if someone subsequently tries to repair it properly.

[Dave Wheatley]

As long as there has been no use of soft (lead or lead free) solder or lead filler there is no reason that dents should not be removable as long as there is 75-80% thickness. It is possible to anneal locally with oxygen/propane or acetylene and carefully tap out the dents with a hardwood mallet on a steel stake.
If the metal is very thin a patch can be silver-soldered into a cleanly cut out area. a good fit is essential as the silver solder depends on capillary action to run into the join and maintain the strength of the piece. Cleanliness and a good fit are absolutely critical.
There are instructional videos on Youtube...
Don't use lead as a body filler, it will make the part unrestorable as even the smallest remaining bit of lead will eat its way through the brass if someone subsequently tries to repair it properly.

That's very interesting Duncan.
My box saloon radiator is made mainly of brass, and is soft (lead) soldered together, but it seems to be holding together so far.

[Robert Leigh]

As long as there has been no use of soft (lead or lead free) solder or lead filler there is no reason that dents should not be removable as long as there is 75-80% thickness. It is possible to anneal locally with oxygen/propane or acetylene and carefully tap out the dents with a hardwood mallet on a steel stake.
If the metal is very thin a patch can be silver-soldered into a cleanly cut out area. a good fit is essential as the silver solder depends on capillary action to run into the join and maintain the strength of the piece. Cleanliness and a good fit are absolutely critical.
There are instructional videos on Youtube...
Don't use lead as a body filler, it will make the part unrestorable as even the smallest remaining bit of lead will eat its way through the brass if someone subsequently tries to repair it properly.

That's very interesting Duncan.
My box saloon radiator is made mainly of brass, and is soft (lead) soldered together, but it seems to be holding together so far.

There is lead free soft solder as required to be used by plumbers these days for soldering joints on potable water pipework. I do not know whether it would avoid the corrosion problems already mentioned. Maybe we have a metallurgist among our number whose knows about these things.
Robert Leigh

[Duncan Grimmond]

My answer was regarding a radiator cowl which I understood to be the brass surround. Lead has the unfortunate property of attacking metals above it in the periodic table at high temperature which is why it was used in assaying silver and gold (cf. cupellation). If you heat to brazing or silver-soldering temperature a gold,silver or copper-alloy article which has been soldered with a lead or even a lead free tin solder, the lead will eat its way into or even through the metal leaving a cokey mess.
Radiators are not run at high temperatures and I think that trying to silver-solder a radiator header tank without removing all traces of lead solder would damage the brass.

[Erich]

Thank you Duncan. In my case, my radiator cowl is steel, rather than brass. The body was built by Ray Pettit, though I am unsure if he made the cowl. I might assume that the steel used was mild, in order to be easily formed, rather than something with a high carbon content.

[daveg]

As a neophyte with body repair that must be plated, I have a question. My radiator cowl is dented. I know that straightening will not eliminate all the dent. So now in the day when body lead here in the US seems to be made of Unobtanium, is there a filler that can be effectively chromed?

Erich in Seattle

I have been looking at this interesting site mentioned in another thread:-

http://www.classic-plating.co.uk/index.html

- they do a "replica chrome plating kit" and state that it will plate non-metallic items if a metallic spray is used. 

I don't know if this applies to normal chrome plating.

[Duncan Grimmond]

I'm not sue if chrome will "take" to lead filler. Usually steel is flash plated with copper and often nickel plated before the chrome. I'd check with the plating company you intend to use and see what they recommend.
If you plan to DIY, you have the luxury (and expense) of finding out for yourself...

[atmacg]

The brass radiator cowl on my 1929 Austin 7 is cracked (torn) at three of the inner corners which frame the radiator core. When I heat the area up to silver solder the crack, the crack opens up. Any suggestions on how to overcome this problem?
Andrew