Changing my heat exchanger zinc, cant get the plug out...help

The pencil zinc in my heat exchanger is in a brass plug in the bottom of the HE.

Head was already rounded before i got started.

Tried medium size gripwise and even applied a little heat but the plug will not budge..

any ideas?

Heat won't help because it will swell the plug which is counterproductive in this case. Sometimes you can sacrifice a 6-point socket and drive it onto the brass but if its too late for that I'd be thinking dremel tool. My goal would be to take it out in pieces without damaging the threads in the heat exchanger. You do that by cutting the sides of the fitting so that you can then collapse it inward on itself until the pieces fall out. You might be able to do a variation on the sacrificial socket by cutting the head of the plug down to fit a size smaller socket. Whatever you do its going to be a long day.

Spray it with PB Blaster or Kroil several times. Tap lightly with a small hammer. Then get whatever kind of wrench will really grab it and it should come right out. Heating and cooling a bit will help too, just make sure you let it cool completely before trying to back it out.

Do you have room to drill out the center and use an extracter? They are reverse threaded bits that look like taps but they spiral. Also, sometimes the matching drill bit is left hand thread too so look before you drill. You can usually buy an assortment at hardware stores. I also like the Dremel idea. Good luck.

Per, what ever you do, go carefully, don't do what I did.

I applied too much pressure and snapped the dam thing off, the whole day turned into a complete 'dogs breakfast', I ended up stripping the thread getting it out, and by 4pm was still trying to rectify the damage I caused at 10am. A job that should have taken 5 minutes and a cup of coffee turned into a 5 hour drama.

By the way, my mistake was drilling out the anode and not keeping the drill bit completly centrered, so I gouged the thread on the Heater exchange, being at the bottom of the Heater exchange it was difficult to set the drill up properly (well that's my excuse).

This probably puts me in the running for the 'Boofhead of the Week' award.

Don't feel bad Andy. It takes a lot of skill and practice to take a hand drill and keep the hole exactly where it belongs. I think most of us are in this boat. I think, if possible, it would be best to take the assembly off the engine and have a machine shop do the work.

Ron

Anthonyd wrote:
Do you have room to drill out the center and use an extracter? They are reverse threaded bits that look like taps but they spiral.

Click to expand...

****** In the Navy we called those "Easy outs" and I have extracted many a stubborn,

****** rounded hex head bolt by this method. Because the hole that is drilled is much smaller

****** than the shaft of the zinc, your chance of hitting the threads and destroying them is

****** slim to none. Tech Tips - Easyout. **

***** Sold at Sears or just Google "Easy Out."

Per wrote:Tried medium size gripwise and even applied a little heat but the plug will not budge..

Click to expand...

*

Applying a "little heat" is a waste of time and effort. Apply a lot of heat, more heat than you feel comfortable applying and do it quickly. Keep the flame on the plug head and be ready to grab the stub with a pipe wrench.

The brass will peel away easily if not gripped securely and if you use a vice-grip it will loosen and just machine off another layer of brass as you have probably already learned. A larger pipe wrench will keep tightening and apply a lot of torque.

Don't be afraid to use heat. The corrosion that lockis the fitting in place acts like an insulator and if a large amount of heat is applied very quickly you will not overheat the metal around it. Tip toeing around will put a great deal of heat into the whole item but not enough in the right place to do any good. You need enough to break the corrosion bond by expanding the fitting then it will rotate easily as it cools when you turn it.

You might even want to consider removing the heat exchanger and doing the job on a bench where you can get at it properly.

Perhaps it's time for a thorough cleaning anyway?

Best of luck.

*

You don't want to put heat on the plug. You want to put it on what the plug is screwed into. Use penetrating oil, let it sit overnight, and get one of those socket sets that have little cams inside them that grab the EDGES of the nut and not the corners. I found a good set at Northern tool to get my stubborn coolant plug out (and it was a square head). Just make sure it fits tightly before you start to apply a lot of pressure. Another tip is to use a long handle on the drive ratchet (I use a piece of pipe about 18" long slipped over the handle). Be patient. It will come out.

http://www.northerntool.com/shop/tools/product_200402514_200402514 (new window)


-- Edited by GonzoF1 on Tuesday 14th of June 2011 05:45:08 AM

I second Leonard, bring it home to work on! As Gonzo said apply heat to the nipple the plug screws into not the plug, with a torch like the ones that screw into the top of a gas cylinder, try to unscrew the plug while the nipple is hot (expanded) lots of tapping on the end of the plug, and alternate trying to screw in and out. Apply kroil or similar before and during the job, but not while it is so hot as to burn.
If the plug corners are rounded beyond use try a stilson (pipe)wrench on it.
Good luck

Because of the different density and makeup in metals, the plug cannot permanently fuse to the exchanger (that's they way someone explained it to me years ago, but I am not a expert... he was), so it WILL come out. With enough force applied (i.e. a wrench that get tighter as more force is applied), it will eventually let go. Luckily, the nipple is not going to twist the head off like a bolt could.

Hopefully the female on the heat exchanger has a hex that you can hold with a wrench while*you yank *the plug. I saw someone twist the heat exchanger once because he didn't have another wrench. (no it was not me).

*

lots of good advice..
my mechanic said pretty much the same, apply lots of heat and dont be afraid to apply some force to the nut.

i already have the easy out drill and reverse out bits, but that will be (second to) last resort.

i am gonna try with a file to make the now rounded bolt back to a square, then get my biggest pipe wrench on it after heat applied.
if it yanks off the welded on female part, i guess the entire thing is going to the shop regardless...

i will keep ya' posted any progress.

I wouldn't waste your time filing it square. It will just round off again and you need more "meat" on the bolt so the twisting force can transfer to the threads without shearing it in two. Pipe wrenches are DESIGNED to grip round things. Ya' know... pipes! Just be aware of putting the wrench on the PROPER direction so that its grip gets tighter the more force you apply. For that job, you'll need a smaller wrench, but like I mentioned, get a good length of stiff tubing to slide over the handle. It will increase the length of the lever-arm and it will make for FAR more force you can apply with the same effort. get it solidly on there first. Then give it a steady, but firm pull. It'll move. I can assure you.

thanks Tom, makes sense for sure.

RickB wrote:

Click to expand...

*

Applying a "little heat" is a waste of time and effort. Apply a lot of heat, more heat than you feel comfortable applying and do it quickly. Keep the flame on the plug head and be ready to grab the stub with a pipe wrench.


*Hi Rick, nice to see you back, you been off working somewhere?* Anyway, I once* recomended using heat to remove a bolt, and you said to never use heat as there was a risk of cracking what ever it was the bolt was threaded into.* I'm wondering what the difference is here?..........
Arctic Traveller

Arctic Traveller wrote:
Hi Rick, nice to see you back, you been off working somewhere?* Anyway, I once* recomended using heat to remove a bolt, and you said to never use heat as there was a risk of cracking what ever it was the bolt was threaded into.* I'm wondering what the difference is here?..........

Click to expand...

*Thanks, just lurking ...

I can't recall ever suggesting not to use heat, if so it must have been a very specialized case as I have always been a strong believer in "fire is your friend" in this regard. Let me know if you can find that because it doesn't sound like something I would say.

Heat must always be applied to the fastener, not the surrounding material. In the case of a steel bolt corroded into a threaded hole, heat it red hot. If the bolt has a nut, heat the nut red hot. While that might sound counterintuitive to those who haven't done it, that is how works.*

In this particular case, if the heat exchanger is a cheapo soft soldered assembly there is risk of it becoming a kit if heat is applied anywhere other than the brass plug and if it is heated slowly.

*

*


-- Edited by RickB on Tuesday 14th of June 2011 01:53:20 PM

RickB wrote:

I can't recall ever suggesting not to use heat, if so it must have been a very specialized case as I have always been a strong believer in "fire is your friend" in this regard. Let me know if you can find that because it doesn't sound like something I would say.

Click to expand...

*Well, I found it.* Perhaps we were talking about something different though, but here it is...................
<h3>Re: Perkins 6.354 manifold <strong style="color:#000000;background-color:#ff66ff;">bolt[/b]</h3> by ambrish » Fri Jun 08, 2007 4:05 pm

Rick wrote,"No no no no no ... you
will never get that hot enough to do any good before doing a lot
of damage to the engine from localized overheating and warping.\n

*Arctic Traveller wrote,
I probably should have added that if you have never
used heat to <strong style="color:#000000;background-color:#99ff99;">remove[/b] seized threads, a great deal of caution is
needed. I agree that careless heating of anything can be
dangerous. Were talking about the EXHAUST manifold here though,
some thing that runs far hotter than you could ever get with a
propane torch. Still if one were to use an Oxy Acetylene torch you
might be able do some damage. Ricks point that localized
heating of cold cast iron might be a problem is correct. Sorry I
failed to mention this, but over the last twenty years, I have done
this probably twenty times and never had a problem. This post caught my
interest because just last month I had a similar issue. I tried
everything but had no joy. I finally heated the entire area with a
torch (soaking the heat in a large area around the stud), and once
everything was hot, I took a can of that pressurized air used for
dusting out computers and stuff, turned it upside down and inserted the
little straw into the hole drilled for the Easyout. When upside
down, instead of gas coming out, liquid Carbon Dioxide comes out at a
very cold temp. This caused the stud to shrink enough that
it came right out. I've done this many times with no problem, but
your results may vary. If in doubt at all, consult a
professional. As with all advice given and recieved here, or
anywhere, it's best to check with multiple sources. Never the
less, I still stand by my original theory that carefully applied heat
will work wonders. ......................Capn Jeff\n

Yeah, it looks like someone suggested heating the manifold rather than the stud. That is exactly the situation where you don't want to heat the surrounding material thinking that it will expand and loosen the bolt or stud or plug.

In the case of heating an exhaust manifold you are talking about a very large thermal mass that is connected to the mass of the engine. You could set the engine on fire and still probably not get the stud hot enough to do any good. Heat the stud by itself, it is corroded in place and the corrosion products are good insulation. You can get the stud cherry red and not even begin to bother the base material. Like Capn Jeff wrote: "... carefully applied heat will work wonders."

Heating cast iron in localized areas is a disaster in the making in any event.

RickB wrote:
Heating cast iron in localized areas is a disaster in the making in any event.

Click to expand...

*That's a fact, but even worse was what I did once looking for a crack in an exhaust manifold.* I made block off plates, and applied air pressure.* A little too much it turned out.* While spraying soapy water on it, suddenly the crack started bubbling, and a nano* second later the whole thing exploded.* Damn near blew my finger off and could have been far worse.* I found chunks of that thing all over the shop.* Huge mistake.* Fortunately I had on safety glasses or I'd probably be blind now. Sorry to have hijacked the* thread................Arctic Traveller

Then I sit corrected. However, I doubt it will get to that. The proper use of torque should spin that thing right out of there. If I had to guess, I would say that the reason it's rounded off on the first place is because a previous owner tried to use an adjustable wrench or vice grips to get it off and tore up the head. Not having the CORRECT tool to fix THAT issue, he (or she I suppose) made it worse in the continued attempt. That's my story and I'm sticking to it. :-D

FWIW... I'll also use the anti-seize squeeze packet stuff (off the counter at Auto Zone they sell you when they sell you spark plugs) between both the anode and the cap head AND a tiny bit on the cap threads into the water jacket. Since then, It takes minimal effort with a brakeline wrench to get the plug out and I can spin off the anode with a good solid finger grip.

this is the wrench i am going to bring



*

Tom, antiseize matter? what the heck is that? or are your taking about the blue lock paste? i guess the anti-seize stuff would help if the PO had used it.

And yes the PO did do the initial rounding of the nut.

btw, i did try one of those sockets made for rounded bolts, worthless.

Per wrote:
this is the wrench i am going to bring

*

Tom, antiseize matter? what the heck is that? or are your taking about the blue lock paste? i guess the anti-seize stuff would help if the PO had used it.

And yes the PO did do the initial rounding of the nut.

btw, i did try one of those sockets made for rounded bolts, worthless.

Click to expand...

NO! Not the locktite! Anti-seize is a non corrosive paste that prohibits the two dissimiliar metals from meshing into one due to corrosion. It's better than most other moly's in this application. Get the hi-temp one, I think it is bronze in color. Applicator is attached to the cap so you don't need to get any brushes. Apply a thin coating around the end of the threads and then run the new one in a couple of times hand tight to ensure you cover all of the threads inside the tapped hole. A little goes a long way. We use it all over the ship's engine room on stuff we know that has long maintenance intervals.*


-- Edited by Anthonyd on Tuesday 14th of June 2011 07:14:26 PM

Beware with all the anti seize compounds , they will stick on your fingers , and not wash off.