7 replies to this topic

[BoboGib]

Model: Jet Black
Year: 1988
Description of problem (please be as in depth as possible):

I somehow have managed to get a hole in one of the cooling cores on my 2 core rad. It's impact damage not corrosion so I understand it can be soldered, being brass/copper. How do I go about doing this. Is it just a case of cleaning the area, heating with a soldering iron the filling the hole with solder?

[Big_Adam]

If its a little hole (we're going to need an estimated sized, not just "its a small hole") then you can just buy some RadWeld dump it in and it will seal it.

Or be old school and put an egg white in.

[Shifty]

To repair properly you'll need something bigger than a soldering iron, a blow torch will be better. Make sure the area really clean, I'd try and get some silver solder to repair it with.

[BoboGib]

Thanks Shifty, I feared the solering iron may not be upto the task. A blow torch is something I don't own. Is there any reason why silver solder is prefered over normal stuff?

Adam, I'd prefer a more permanent repair without the knowledge that there is rad weld potentialy blocking and clogging up the rest of the cooling system.

[dklawson]

I will present a different set of comments.

First, a soldering iron will be up to the task. However, it will likely not be one you have in your collection. You do not use tiny (electronics) 30 Watt iron for this, not even a 100 Watt iron. You need a gun rated for something close to 400 Watts or a LARGE plumbing iron.
Preferably one of these: http://www.projectau...ering_irons.jpg
or maybe one of these: http://ecx.images-am...L500_AA280_.jpg

When soldering radiators, you want to get the heat in quickly and move on. A torch heats too broad an area and you can damage areas you don't want to affect.

With all soldering, success is the prep work. The area must be bone dry, free of all paint, oil, grease, dirt, and down to shiny metal. You have to use a good flux that will both conduct heat into the work area and clean oxides off the metal surface. Apply the flux to the radiator then add a pre-heated iron and the solder. Do not use resin core solder and expect its flux to be any good for this task.

When the term "silver solder" is used, be careful. There is "silver bearing soft solder" and "silver solder". These are two entirely different products. For brass and copper plumbing repairs you want soft solder and it does not necessarily have to have any silver in it, lead/tin will be perfectly fine. True silver solder is often slightly gold in color due to other materials in it. It is much, much harder and has a much, much higher melting point. You would NOT use true silver solder on a radiator core.

I do not use radiator stop leak compounds lightly. On almost every car where I've seen them used, the inside of the radiator and engine block are coated with strange slimy coatings or plugged. It may stop a leak but often at the expense of heat transfer. Egg is an old tradition known to work but it's obviously messy and can plug up areas just as badly as the stuff from the parts store. If you want to try a DIY fix that doesn't involve liquid goop from the parts store or egg, try ground black pepper. That's the other DIY fix from years gone by. Unlike other "dump it in" fixes, the pepper won't stick to anything in the block or radiator until it finds its way to the hole. However, chances are, your stone damage will be too large for any DIY "dump it in" fixes. Soldering at home or a professional repair are probably in order.

[BoboGib]

Thanks Doug.

Would something like THIS be up to the job. If not I might look at getting it repaired rather than doing it myself. May work out cheaper.

[dklawson]

The butane torch in your link would probably work but I would practice with it on something else first.

However, look carefully at the cost of that torch and weigh its potential future uses against the cost of having a shop repair your radiator professionally. If you cannot imagine using that butane torch for other purposes to justify the expense... give serious thought to having a radiator shop handle this for you.

[Big_Adam]

Adam, I'd prefer a more permanent repair without the knowledge that there is rad weld potentialy blocking and clogging up the rest of the cooling system.

You make a point, but I dumped some in my 82 and all was well. Rather spend £3 see how it goes then be up the creek with a stuffed radiator. However, I'd check local welder / car places. Rather than messing with getting all the parts yourself, ask local car repair place (pref one with people working over 20year old) where they would get it fixed, they'll either say they'd replace it, radweld it or send it to guy X Y Z.