Just when you think it's safe to go back into the water....

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frenchblatter
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Just when you think it's safe to go back into the water....

Post by frenchblatter » Tue Jun 23, 2020 3:44 am

.... you find that apart from a warped head you also have a leaking core plug.

Back in the day we used red lead, a mixture of lead powder and red hermatite to seal core plugs, what is used now?

(XPAG engine in a TC)
Lynne & Norman Verona.

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stephen stierman
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Re: Just when you think it's safe to go back into the water....

Post by stephen stierman » Tue Jun 23, 2020 9:41 am

Norman, I used to work for a CAT dealer and when they replaced core plugs they coated the edges with a two part gray epoxy that looked suspiciously like JB Weld. So that is what I use and find no problems.

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Steve Simmons
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Re: Just when you think it's safe to go back into the water....

Post by Steve Simmons » Tue Jun 23, 2020 9:53 am

Considering the system has zero pressure, I find it rare that I have to use any kind of sealer on the plugs. If a block has pits then I may use a tiny smear. Two products I've used with good results are Locktite sleeve retainer (usually only on pressurized systems) and a small smear of Permatex Right Stuff when the surface is rough. I've heard of people using JB Weld to fill pits and then sanding it smooth but it seems like it might be hard to get it perfect. I've also seen people smear JB Weld on top of a fitted plug but this seems totally unnecessary to me, and probably a pain to remove and clean later. I've never tried it personally though, so maybe it isn't as bad as it seems.
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Duncan M
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Re: Just when you think it's safe to go back into the water....

Post by Duncan M » Tue Jun 23, 2020 8:54 pm

Might try some regular blue Hylomar to fill any fine pitting on the block where the plug seats.

frenchblatter
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Re: Just when you think it's safe to go back into the water....

Post by frenchblatter » Wed Jun 24, 2020 2:55 am

With a 70 year old casting I think it does need a sealant. As I said above we used to use red lead, even on newish blocks.

I've ordered some of this: https://enginecoreplugs.com/product/cor ... ml-tube-2/ Problem is it's coming by post so may take week or so to get here. If it does I have Hylomar in stock so I'll use that although it's not meant for sealing core plugs, it's for ali-ali gasketless joints.
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Tom Lange, MGT Repair
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Re: Just when you think it's safe to go back into the water....

Post by Tom Lange, MGT Repair » Wed Jun 24, 2020 5:00 am

If one steel core plug is leaking, others will surely join the chorus, and start to leak without warning. Brass ones are without question the best, and will never leak.

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stephen stierman
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Re: Just when you think it's safe to go back into the water....

Post by stephen stierman » Wed Jun 24, 2020 7:52 am

JB Weld works just fine for filling pits and building up alloy castings, particularly like the typically corroded thermostat housing on your TC. Why wouldn't you be able to sand it smooth, it's just like any other epoxy? You know that gas tank sender in your petrol tank that always leaks and screws up your nice new paint job? Well JB works just fine as gasket sealer and takes care of that and is impervious to fuel. It has pretty decent heat resistance too. Not difficult to remove as it really isn't a weld. "Bad as it seems", but you've never used it??

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Steve Simmons
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Re: Just when you think it's safe to go back into the water....

Post by Steve Simmons » Wed Jun 24, 2020 7:58 am

Yes, I've used it, just not on core plugs because mine don't leak. But I know others whose plugs do leak and have used all sorts of products with mixed results. I use Right Stuff on all other areas of the cooling system - thermostat, elbow, rear plate, etc and it works marvelously, on both pressurized and non-pressurized systems. In fact I use it on just about anything I need to seal on an engine. Best general sealer I've used!
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jddevel
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Re: Just when you think it's safe to go back into the water....

Post by jddevel » Wed Jun 24, 2020 9:42 am

Is Right Stuff available in the UK? Google doesn`t indicate it is unless under another name. Who are the manufacturers please?

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Re: Just when you think it's safe to go back into the water....

Post by Steve Simmons » Wed Jun 24, 2020 9:48 am

Permatex makes it. The black stuff is what I use. It comes in 1-minute and 90-minute versions. The aerosol can is really useful and makes it super easy to apply just the right bead. It also doesn't dry out in storage, although the nozzle can get plugged after a while so you have to clear that before using again.

See here: https://www.permatex.com/product-catego ... et-makers/
1949 TC8975 / XPAG 9609
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Re: Just when you think it's safe to go back into the water....

Post by frenchblatter » Fri Jun 26, 2020 2:51 am

This core plug is probably leaking due to me not realising teh head gasket was leaking and driving the car with no water in it. The block got very hot. The other two look good but I do have new ones in case they start to leak.
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