Home > Uncategorized > Fixing a plastic radiator

Fixing a plastic radiator

December 9, 2008

On taking my ‘88 Civic in for an oil change a couple weeks ago, I learned that the radiator had a crack on top where a mounting bracket attached.  A new radiator is $300, give or take, so I decided to take a “crack” at it.

It’s a plastic radiator so the usual remedy of soldering some brass metal over the crack wouldn’t work.  Fortunately my garage is stocked with various chemicals and adhesives. 

I scraped the paint off with my pocketknife and cleaned the area with some carburetor cleaner.  Then used a small (disposable) paintbrush to apply a thick layer of POR-Patch, a phenomenally agressive and strong adhesive/sealant.  I allowed it to set for a couple days (cold weather – 8 hours would have been enough in warm weather) and then applied a reinforcing patch made of cotton from an old pair of slacks, painted in place with POR-15 “paint”

Normally these products set fully within 96 hours but I gave them ten days because it is very cold outside.  On testing, the repair is quite secure and does not leak.  Yea!!!

I put the word “paint” in quote marks because POR-15 is more like a reactive adhesive coating.  It is difficult to work with for a number of reasons; the fumes are toxic, it is very thin, it takes a long time to set, and you have to be careful what you get it on.  For instance, don’t get it on the threads of anything you ever want to unscrew again.  When you put the lid back on the can, you have to wipe off any vestige of the stuff or you won’t be getting that lid off again without destroying the can.  If you allow it to set on your hands, it will stay there until the skin cells slough off days later.  It expands slightly as it sets.

With those difficulties, you’d think it would a product to avoid, but it does have its uses.  It is completely invulnerable to solvents – you can even use it to refinish the inside of a gas tank.  Battery acid does nothing to it. It sets so hard it’s difficult to sand.  And with a chemical pre-treatment, you can even paint the stuff directly onto rusted metal and the rust will not return. 

POR-patch is just a thicker version of POR-15.  Squeeze some out onto a chunk of cardboard and re-cap immediately so what’s left in the tube doesn’t start reacting to air.  Thoroughly wipe off the threads of the tube before putting the cap back on.

(No, I don’t get any money from the company.)

Categories: Uncategorized
  1. Still Me
    December 9, 2008 at 14:02 | #1

    It is good to know about this.  I have never found a glue product that can do all it claims it can do.

  2. gruntled atheist
    December 9, 2008 at 18:15 | #2

    How cool is that?  I had not heard of POR but I will not forget it.

  3. December 9, 2008 at 19:05 | #3

    You’ve just given me an idea for a post! (That’s solid gold to a blogger) There are a half-dozen adhesives I use for different things.  I should write a post comparing them and their uses, limitations, etc.  :coolsmile:

  4. December 9, 2008 at 20:07 | #4

    I would love to hear about the different kinds of adhesives seeing as how I am fix-it man in the making.

  5. Still Me
    December 9, 2008 at 23:12 | #5

    George, I got to thinking that, after you write your brilliant post about the various adhesives, you could follow up with a comparative report of growth rates of different grass species.  Then maybe finish the series by presenting an fascinating treatise on drying rates of different paints.

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