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Fixing a cars radiator

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 Recently I got a crack in my radiator and found out its going to be $300 just to buy a new one, and thats If I installed it myself, it was going to be around $500-$600 to have someone do it for me, I looked into other ways and here's what I came up with. Total cost $16, time 15min. lasts forever.
 
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Step 1: Materials

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 I went to a local napa automotive store, and found a kit that is designed to fix cracks and holes in plastic parts on cars and containers. It's a fiberglass repair kit and only cost about $16. 

Step 2: Directions

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 I followed the directions that came with the kit but there were a few things the directions said to do that didn't work as well as they claimed, I'll talk about what I found that happened or worked better in other parts as they come up.

The kit came with  a strip of fiberglass cloth,. sand paper, a metal tube 1 time use brush, and a 2 part epoxy.

Step 3: Other Tools

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Some other tools you'll need is a few simple things.

1.Scissors for cutting the fiberglass cloth to correct shape.
2.some sort of tool to scrape off excess material during the cleaning process, I used a small pick, a screw driver would work just as well.
3.A drill and a drill bit, the drill and bit are used to ensure the crack doesn't spread, Ill explain all that in detail
4.  air filter mask, I used a simple painting mask, but any filter mask would be fine.

Step 4: Cut the fiberglass

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 Cutting the fiberglass is really easy. it is just like cutting normal fabric so normal scissors work fine.

Step 5: Preping the area

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Make sure you scrape all excess dirt, grease, or any other dirt off, and wipe clean with a cloth or a rag, don't use paper towels because the may leave traces of fibers behind. Then use the sand paper to sand anything off that is left behind, and in order to give the fiberglass a surface to stick to.
radmanaa1 year ago
I have been in the radiator repair business for 33+ years I own my own shop in southern California and I can tell you that won't work for a permanent repair. It may buy you some time a week or a month but it will not be permanent. I have seen hundreds of these attempted repairs with every glue you can imagine and nothing works.
radmanaa3 years ago
You can't fix it. You can replace the cracked tank with a new one but that is just as expensive as buying a new radiator. The tanks are made from injection molded plastic and there isn't a product on the market that will vulcanize with it. Epoxy, glue gun, zip ties, and other things people have come up with here are temporary fixes (one or two days if you are lucky) because your radiator expands and contracts causing any substance you try and fix it with to crack loose as soon as you run the vehicle a few times. Also don't use stop leak as this will plug up everything but the leak. Sorry for the bad news. The best answer is to just keep adding water till you can afford to replace the radiator. www.intermountainradiator.com
I'm sorry your repair did not succeded.  Most Radiator tanks are made with Nylon 6-6 mixed with short fiberglass mixed in a 70-30% mix. Replacing the radiator with a new one is out of the question, as it goes AGAINST THE SPIRIT OF INSTRUCTABLES and the DIY BIBLE too...  We WANT to presume that we were successful in repairing almost anything!

THE secret for a successful repair, is based on getting several things properly done:
1) CLEANLINESS of the surface where the patch will be attached to.
2) REINFORCEMENT of the patch (that is why fiberglass mat is for).
3) Use of a GOOD resin to make the repair.  More below.
4) PROPER surface finish where the patch will be grabbing.
5) Application INSIDE the epoxy time window.

(1) Clean throughly. Sanding first is a must. The suggestion on using a strong cleaner ("Brake Cleaner") can be either a large help, or a failure point, depending on the TYPE of cleaner: nowadays there are TWO distint classes of Brake cleaners: Those containing Clorinated agents, and those based on Non clorinated solvents. Let´s ask the commenter that suggested its use to please tell us which one did he use. In any case, let the solvent evaporate at least 2 minutes to avoid trapping solvent that will weaken the epoxy.

(2), (3) and (5) For the fiberglass mat to provide a good mechanical resistance and attachment to the radiator material, it needs to be completely and throughly wetted with the epoxy. THEREFORE, you need to perfectly wet the textile with the epoxy, which means that a too viscous, paste like epoxy is NOT going to wet the fiberglass.  Thus, I may suggest that instead of using a "Patch Kit", why not go to a Model Airplane Hobby shop and purchase a finer weave Fiberglass Cloth and a much SLOWER epoxy resin, called "finishing resin", usually over two HOURS setting time. That will give you plenty of time to wet the cloth, get inside every microscopic ridge and channel onthe nylon tank, and level itself to give a nice appearance too.  Any epoxy faster than that wont give as good a result.

(4) A rough (but not too rough) surface is best. Try using 120 or 150 sanding paper (wet--or-dry type is better).
 Enough thickness is necessary to achieve the required strenght, this means two to three thin cloth layers (2 Oz per square yard cloth).  Even when the hobby shop cost of the Finishing resin and cloth will be higher than the NAPA (or similar) patch kit, it will produce a much better patching, that, when properly done will outlast the car.  Mt two cents.  Amclaussen, Mexico City.

P.D.: The suggestions about using "JB Weld" are not good, because JB Weld has metallic filings as reinforcement, but several layers of thin fiberglass cloth are a much better reinforcement, albeit a little slower and requiring more dexterity.  The reason the fiberglass cloth is much better, is that it has much higher tensile strenght AND it has a very similar thermal expansion behavior than the nylon tanks.  JB Weld does not perform as well.
tundrawolf1 year ago
Way to go. A word to the wise, a little spray of brake cleaner will soften the plastic up just a tad, giving the right epoxy a chemically tight bond. It will also remove any contaminants as well. I use brake cleaner on inner tubes when I patch them, to get all the junk off. It works...
tundrawolf1 year ago
Way to go. A word to the wise, a little spray of brake cleaner will soften the plastic up just a tad, giving the right epoxy a chemically tight bond. It will also remove any contaminants as well. I use brake cleaner on inner tubes when I patch them, to get all the junk off. It works...
Karletto5554 years ago
i tried it with special liquid which you pour into the radiator and it closes the hole(s)
.. didn't help but  the hole was quite big
Vikking (author)  Karletto5554 years ago
 stop leak only works if you have a pin hole in the metal part of the radiator, for large holes and cracks you need to do something like this for the plastic parts or if it's metal use JB weld
k5cqb Vikking1 year ago
Hi Vikking,
My radiator just sprung a pinhole leak and I was wondering how your repair has held up so far?
Vikking (author)  k5cqb1 year ago
since the crack was so large, it lasted a little less than a year, the plastic kept separating, the process i showed is more for pinholes, i was just trying to save it until i got a new radiator. this process should work for pinholes with no problems, the problem i kept having it it kept pealing off, so make sure you scuff up the plastic and give it something to hold onto
ths Karletto5554 years ago
 Stop Leak only clog your radiator, don't put that in your rad.  When I replaced my rad, I had to drain the coolant by removing both input and output pipe from the rad (the rad itself was clog)

This instructables at least doesnt clog your system
dbtk443 years ago
Nice tutorial! I used this same procedure, very successfully, on a 4" crack in my radiator. A year and a couple months later, it's still holding like a champ. Even being severely heated ( due to a bad thermostat ), it's held just fine. Of the 5 other products I tried using to patch it ( JB weld, epoxy putty, etc.), this one is the only permanent solution; the others just flaked off or leaked.

Just a little piece of advice for anybody who has a cracked radiator..try and patch it ASAP, because the intermittent low coolent level, and the heat, will effect your water pump and your thermostat. Thermostats are easy to change out, and probably not a bad idea just to do it if you've been overheating anyway. Water pumps, depending on your vehicle, can be a nightmare to DIY or very expensive to have it done.

Anyway, again nice tutorial! I highly recommend this stuff
johnny3h4 years ago
Good job on the tutorial. I have used this technique in the past, and it worked well. However, it was years ago, and a different brand of kit, but I suspect that today's products are better due to technology improvements. The only addititional advice I would add is to BE SURE the surfaces to which the epoxy is to be applied are TOTALLY CLEAN and dry. That means no grease, oil, fingerprint oil from your hands, or any other contaminent. These will prevent a good, uniform bond. When I repaired my radiator tank, the first thing I did was to thoroughly wash the entire upper tank with Dawn Dishwashing Liquid [an excellent detergent, but 'gentle.']. After thorough rinsing, I allowed it to fully air dry before then following all the directions on the package.
IfWeChoose4 years ago
Nice instructable. JB Weld fixes anything
Vikking (author)  IfWeChoose4 years ago
 it isn't JB weld, JB weld doesn't work on plastic, I used fiberglass and epoxy
 Oh sorry, I should have read the first page. Well JB Weld does work on plastic but your alternative is more secure.
Vikking (author)  IfWeChoose4 years ago
 I did try JB weld first because thats what I already had but in about a month it flaked off, so far this has held strong.
Yeah the same thing happened to me, it opened back up a few months later.
StarBlades4 years ago
hahaahahah is that a nissan altima lol
Vikking (author)  StarBlades4 years ago
 it's a 98' Nissan altima, the crack in the radiator is the first problem I've ever had with the car
Don't worry about any other problems coming up either. How many miles you got? Might want to flush the radiator, the coolant gets chunky when its old and can cause cooling issues.
Vikking (author)  IfWeChoose4 years ago
 i have around 130k miles, I'm actually going to keep looking for a new radiator just so i dont have any future problems, but so far this fix has done the trick, if anything changes I'll post another comment letting people know what to expect

Yeah that's a good idea. Good luck!

Sometimes buying a used one and having it rebuilt could be cheaper than buying a new one. For a car I had in the past, I had the radiator rebuilt. It's usually hard to find local places to do it. Cost me $100 to make it brand new. Depending on how bad the opening was on your current radiator, they MIGHT be able to make an internal and external patch to make it brand new, leveled and everything. Just thought I'd let you know! ;)
i have the same, nissan altima 98.
i have 200,000+ and no problems. i have a small oil leak but thats no problem. i do all the maitenance myself, im an auto apprentice first year.


pillow39714 years ago
P.s. Never pay any one to replace your spark plugs, all you need is like $4 worth of tools from an auto part store, and 4 new plugs, and the whole job cost you maybe $25 and 10 mins. Just realized I have that exact same care (98 Nissan Altims)
pillow39714 years ago
I have a Nissan Altima with the same exact crack. Gonna try this tomorrow when the auto part store opens. Thx for posting, I found a radiator for $130 online, but don't feel like spending more money to fix this damn car..
dombeef4 years ago
 You could also put an egg in it...
eight dombeef4 years ago
Yes an egg can work as can MUSTARD.

Rumours that if you fill your radiator with milk, you get a free Cappuccino frother are debatable !  ;- P

Nice post by the way !!
dombeef eight4 years ago
 Yeah!
Gave me a good laugh today thanks!
But how mustard? Does it gelatinize (Is that even a word?) in the hole?
eight dombeef4 years ago
Mustard swells up like a sponge to fill the gap... in theory. Just a temporary fix until you can get it fixed or do this instructable.
dombeef eight4 years ago
 Oh ok Thanks!
eight dombeef4 years ago
It is my pleasure Dom !
dombeef eight4 years ago
 Yeah  My username is odd...
eight dombeef4 years ago
Um yeah, but hey, I'm not gonna say a word, my friend... ;-D
dombeef eight4 years ago
 Ok...
And what is your picture of?
eight dombeef4 years ago
dombeef eight4 years ago
 OK now you are calling me a cow
Thanks...



lol
 But Yeah that is a cool show
 :O
Toxictom4 years ago
Old school mechanics would dump black pepper into a radiator to fix small pinholes.   
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