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Can JB Weld fix a cracked cylinder head? See the proof!!

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May 11, 2017

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Can JB Weld fix a cracked cylinder head?  See the proof!!
Can JB Weld fix a cracked cylinder head?  See the proof!! thumb Can JB Weld fix a cracked cylinder head?  See the proof!! thumb Can JB Weld fix a cracked cylinder head?  See the proof!! thumb

Transcription

  • You know I've always heard that JB Weld can fix a cracked engine block or a cracked cylinder head
  • But I've never seen it done
  • And I don't know if you have either but today we're going to find out once and for all if JB
  • Weld is up to the task of fixing a cracked cylinder head. There's nothing wrong with the cylinder head on this lawnmower engine
  • But I'm going to go ahead and basically simulate having a crack
  • I'm going to take a cutting blade out and cut through this cylinder head, and then fill it with JB
  • Weld, allow it to dry for 24 hours
  • Reattach the cylinder head, and then see if it will take the pressure and the heat
  • Additionally I have a hole in this gas tank that goes to this lawnmower
  • I'm going to hold it up here and as I tilt it forward
  • Gasoline is going to start to ooze out of it. I've got a pretty good-sized hole right up in here
  • You can see it pours out quickly and JB weld is supposed to be resistant to gasoline
  • So we're going to find out if JB Weld can also fix this gas tank while we're at it
  • The first thing I want to do before I
  • Cut into this cylinder head is to go ahead and clean up a lot of this
  • buildup so I'm going to use some carburetor cleaner
  • This is definitely clean enough, so what I'm going to do now
  • is just cut through part of this cylinder head, and then apply some JB Weld
  • So as you can see I've made a really big gash in this cylinder head and
  • it's so big I can easily slide a zip tie through it and
  • This is going to be a true test for JB Weld to see if it can patch up this hole
  • In order to make this cylinder head repair the first thing we need to do is to go ahead and bevel out
  • on each side of this of
  • This cut in order for the JB weld to have something to hang on to and we're going to rough this surface up a bit
  • Okay, as you can see there's clearly a hole, and I've went ahead and beveled out around this this long gash
  • And now what I'm going to do is mix up the JB Weld and go ahead and begin applying it into this crack
  • JB Weld comes in... for those who have never used it comes in two different tubes and
  • You just basically mix fifty-fifty
  • And so what we want to do is just work this into the crack, just sort of pushing down on it
  • And we'll flip it over in a minute, and we'll see if it's if it's flowing into the crack
  • Again, we're just sort of trying to massage it into the crack and this stuff is going to want to flow on us
  • This is what it looks like now. We'll check back in about 24 hours and see how it looks
  • Okay, the JB weld has cured as you can see this is where the cut was at this is where I had beveled and there's
  • A slight indention there, but this should work very well, now I'm going to flip this cylinder head over real quick
  • as you can see this is where the JB weld started to seep through
  • So what I did was I put a little bit of tape down to keep it from leaking on through and draining if you will
  • So right through here was where the crack was at and as you can see the JB weld has done a great job
  • Of covering up this crack, now
  • I have already pressure tested this tank. The way to pressure test the tank is to seal off the
  • gas cap area where you add fuel and to basically put pressure through the... where it drains into the
  • Carburetor, just add some air pressure to that to see if it holds. There was no more leaking air
  • So I know this is a really tight seal, the question though is can it stand up to gasoline as JB Weld claims it can?
  • Since the cylinder head came off of an engine that had low compression
  • I want to go ahead and give this a really rigorous test
  • I'm going to put this on a different engine that has very good compression, in fact over a hundred pounds of compression
  • So this should give it a really good test. So you're going to see me switch out mowers from the one I took this off of
  • Okay, so we've got the cylinder head installed now
  • I want to go and put this fuel tank on. As you can see right here. This is the JB weld
  • This is where the crack was at right here like I said I pressure tested it
  • I think this is going to hold fuel, so I'm gonna take a perfectly good fuel tank off of this machine and put the
  • Repairing tank on to see if it's going to hold
  • Okay I'm going to spin the engine over five times
  • Wow, that's great compression, about 110 pounds of pressure. That is really putting this head to the test
  • Okay, we're about to do the ultimate test. One thing I've done is I've added an oil temperature gauge. This
  • Mechanical Gauge, the sensor is fed right into the where the dipstick goes
  • And I have created sort of a seal over here to keep anything from spewing out as the engine's running
  • So you will see this temperature rise. I'm expecting up to 160 - 180 degrees, that's going to be our oil temperature
  • Additionally what you're going to see here is the temperature of the spot where you see the little laser dot.
  • All I can say it's very impressive results, the JB weld held up as you saw the temperatures exceeded 300 degrees Fahrenheit
  • Additionally the oil temperature is about 190 degrees at times. I also want to say the fuel tank held up
  • It's leaking a little bit around the gas cap and not the actual crack itself
  • So that's a problem with my gas cap not not the repair, but I'm going to take the cylinder head off in a minute
  • But if you heard there's a little bit of a ticking sound in the motor and that was because the piston was coming in contact
  • With the JB weld. One thing I should have done was sanded down the JB
  • weld because it was a little too thick and
  • Therefore the piston was hitting it. So I've just had this thing running at least 20 minutes and this engine runs at at least
  • 3,000 RPMs so basically the piston has slapped into the JB weld at least
  • 60,000 times in the last 20 minutes
  • and it still held up despite all that impact. So all I can say is if
  • JB weld can hold up in this engine, I'm pretty confident it can take on just about any task you have
  • for it. I'm gonna spin the engine over five times
  • Okay, guys looks like the JB
  • Weld did a great job holding up. You can see some some carbon deposits on the JB weld,
  • but there is absolutely no cracking, no issues with this at all. I am extremely impressed with what JB
  • Weld was able to do. That tapping we heard
  • Let's take a look at the piston and see what it was, see where it was hitting at
  • So you'll notice here, there is a spot. That's a lot lighter colored as well as here
  • This is where the piston was coming in contact with the JB weld and as you can see the JB
  • Weld held up really well, it did not do any damage to the JB Weld, obviously didn't do any damage to the piston
  • It was barely tapping it was just barely tapping the JB weld
  • But it just goes to show the strength and durability of this product. Okay
  • I went ahead and ground off some of the JB Weld
  • I want to see if this is still going to work okay
  • I think it will do just fine
  • And I grounded off just because I want to get rid of that knock, so let's see how it sounds
  • and see if it's back to normal
  • Is that impressive or what? JB Weld
  • Held up to a pretty tough test. You have to admit that cylinder had got pretty hot and it didn't come apart
  • Additionally the piston was slapping that cylinder head pretty hard
  • And it slapped it about sixty thousand times and still did not break and so that was unplanned
  • That was just my fault. I should have sanded that
  • Excess JB weld off that cylinder head, so the piston wasn't slapping it, so I admit I made a mistake there
  • But anyway, all I can say is I am very impressed. The fuel tank held up as well, so in both tests
  • It showed that it's a good product. Just as a final reminder, I am not sponsored in any way by JB
  • Weld or any of the manufacturers of the products that are right behind me here. These are all
  • products that I purchased using my own personal funds. So my question to you today, the question today
  • and I love reading your comments, is what have you used for making repairs? Have you used JB weld
  • before? And is there a better product that you would like me to test for fixing a cracked or a
  • cylinder head with a hole in it?
  • Because I'm looking forward to testing the claims and testing the quality of these different products
  • And you guys, I learn a lot from you
  • You have a lot of great ideas, so I look forward to reading and responding to your comments
  • Look forward to seeing next time on the next episode. Thank you

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Description

Is JB Weld as good as they say it is? Can it repair a cracked cylinder head? How about a cracked plastic fuel tank? Will it withstand fuel? In this video, I put JB Weld to the ultimate test!