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vinegar in radiator?


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There are substances actually designed just for this job that are safe for all the metals inside your cooling system and probably do a better job. Admittedly they aren't as cheap as vinegar, but is that really a place to cut corners?

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6 hours ago, Buick35 said:

I read and tried using vinegar as a rust remover and wonder how it would work to clean the cooling system on my 35 Buick. Anybody ever try it? Greg.

Vinegar is a weak solution of acetic acid https://en.wikipedia.org/wiki/Vinegar


There are solutions used to clean tubes in water cooled refrg/air conditioning shell & tube condensers.  Tend to be stronger acids.



Another engine cleaning thread



Edited by 1939_Buick (see edit history)
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If your water jacket is clogged with rust you are going to need stronger measures. Vinegar is great as loosening rust if you can brush it off. I don't know how to get brushes into a water jacket. Maybe if you fill the system with vinegar, soak it for a few hours, and then start the engine, it will be like brushing it off. The way to know is the drain water should be dark red or black.

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Get yourself an infrared thermometer and check all around your block and head when the engine is up to operating temperature (at least a 20 mile drive).  You will probably see that there is almost not circulation around cylinders seven and eight.  If this is the case then knock the core plugs out and physically remove the crud from around the cylinders.  An infrared thermometer is a fantastic tool to have.

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GM in some of their parts books refer to plugs in the block or head as expansion plugs.  I suppose anyone replacing one would be expected to know what type they had.  Sometimes GM called welch and/or expansion plugs plugs by their correct name, but not always.  Of course we also have expansion plugs that are rubber and expand when tightened.

Core plugs are used to fill the sand casting core holes found on water-cooled internal combustion engines. They are also commonly called frost plugs, freeze plugs, or engine block expansion plugs.Wikipedia

The Welch plug, (misnomer: Welsh plug), is a thin, domed disc, of a metallic alloy, which is pressed, convex side out, into a casting hole and against an internal shoulder.[4]Alternatively a non-ferrous metal such as brass offers improved corrosion prevention. When struck with a hammer, the dome collapses slightly, expanding it laterally to seal the hole. Other core plugs have a dish design, so that when pressed into the casting hole the tapered sides form the seal.

According to Nevin Hubbard of the M.D. Hubbard Spring Company, the Welch plug was originally designed in the 1900s by the Welch brothers at the Welch Motor Car Company of Pontiac, Michigan. Hubbard claims that "at that time core holes in the engine blocks were fitted with pipe plugs. During one of these run-ins a pipe plug backed out. In order to get back on the road one of the brothers drove a quarter or half dollar into the hole. From this they developed the Welch plug, some with the help of my great grandfather Martin Hubbard. They then patented the plug and the M.D. Hubbard Spring Company became the sole manufacturer of the Welch plug for the life of the patent.


I would never refer to one of these as a freeze plug, or more correctly would never ever trust one of these to protect my engine if it had water in it and the temperature went below freezing.  I personally have seen at least ten blocks that were cracked by frost and the core plugs were still intact in the block.


cup type (1).jpg


Edited by Guest (see edit history)
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