Head gasket maker.

I have never used the anaerobic stuff, so I can't vouch that it will work or not. Some have used the red or orange stuff, can't remember which, but claim to have had good success. I'd verify if I were you before going on my word.

I use Permatex Ultra Gray: Amazon: Permatex 82194 Ultra Grey RTV Silicone Gasket Maker.

It is used on auto transmission cases and motorcycle crankcases. It is recommended for high vibration environments. I've had good luck with it on my motorcycle engine. Personally I think it is a good substitute for Yama-Bond (Yamaha RTV motorcycle gasket maker) and cheaper. YMMV (your mileage may vary )

A few years ago, I lacked a good crankcase back gasket for a venerable 1966 OS Max .10R/C cross scavenge engine. It was an E-Bay buy, gummed up and needed a good cleaning. When I started disassembly, back gasket was toast. I used Ultra Gray, and it worked like a charm. On my test stand, engine ran well on start up, needled and throttled well.

Since, I've used it on my other model plane engines, and it works well. YMMV .

Permatex Brochure wrote:PRODUCT DESCRIPTION, S.I.N.: 834-300

Permatex Ultra Gray Gasket Maker is a single component, room temperature vulcanizing gasketing compound designed  to provide reliable “formed-in-place” gaskets for mechanical assemblies. This material cures on exposure to moisture in the air to form a tough, flexible, silicone rubber gasket. The product resists aging, weathering and thermal cycling without hardening, shrinking or cracking. Designed to perform under the higher load conditions of engines with closely spaced bolt patterns (typically non-US designed), and maintains outstanding oil, water-glycol resistance. OEM Specified.

PRODUCT BENEFITS
• High load resistance
• Improved oil resistance
• Sensor safe, non-corrosive
• Replaces most cut gaskets
• Can be used as a gasket maker or dressing
• Non-flammable, Non-toxic
• Low odor

Anyway, again, YMMV.

Not only No!, but....

Head gaskets do not only seal the glow plug against gas pressure leak-by, they also set head spacing. How are you going to use a fluid (yes, the sealant is a fluid) to set the head spacing for 25% nitro vs. 35% nitro? You can't. Also, nothing on my tube of Permatex sealant mentions heat capability. I'd bet that at the temps our heads run, you'd melt and blow through the sealant if you tried.

The Leaky Mark

batjac wrote:Not only No!, but....  

Head gaskets do not only seal the glow plug against gas pressure leak-by, they also set head spacing.  How are you going to use a fluid (yes, the sealant is a fluid) to set the head spacing for 25% nitro vs. 35% nitro?  You can't.  Also, nothing on my tube of Permatex sealant mentions heat capability.  I'd bet that at the temps our heads run, you'd melt and blow through the sealant if you tried.

The Leaky Mark

May depend on the type of engine (he didn't say it was a Cox), but I would suggest that sealant on its own wouldn't withstand cumbustion pressure for long.

My McCoy Red Heads use a paper head gasket, but then they aren't competition engines either. Regarding use for head gasket, misread the OP's question. Regarding Mark's concern, depends on the engine. The smaller Cox, yes, adjusting compression via copper or aluminum head washers helps adjust run conditions based on type of fuel.

There isn't a one size fits all type of sealant around, and each situation needs treatment on an as-case basis. Some use red / orange rtv to seal the heads on K&B Sportsters. Earlier .20 Sportster uses a rubber O-ring as a head gasket.

If I lack and I try and it works, it works. If it doesn't work, then try something else. Nothing is cast in stone I know of. (But then I'm the one that likes oddities like A.C. Gilbert Thunderheads and Testors McCoys, OK Cubs and glow plug adapters on Norvels. )

A gasket is one thing a Compression ring is another witch we know , so it may wood work for a long time as a gasket . I went with the thought it was a Cox engine !?!? And we still don't know.

Guy's, engine I was talking about trying this  on is one of the older  fox .15 engine. Here is the product.
https://www.amazon.com/Permatex-51031-Temperature-Anaerobic-Sealant/dp/B000HBIEG4/ref=sr_1_2?ie=UTF8&qid=1525805807&sr=8-2&keywords=permatex+anaerobic+gasket+maker&dpID=41r%252BPs6tIpL&preST=_SY300_QL70_&dpSrc=srch

I have made a gasket out of a beer can for now and will see how it holds up.

batjac wrote:Not only No!, but....  

Head gaskets do not only seal the glow plug against gas pressure leak-by, they also set head spacing.  How are you going to use a fluid (yes, the sealant is a fluid) to set the head spacing for 25% nitro vs. 35% nitro?  You can't.  Also, nothing on my tube of Permatex sealant mentions heat capability.  I'd bet that at the temps our heads run, you'd melt and blow through the sealant if you tried.

The Leaky Mark

I should have been more specific about what I was thinking about using it on.


What temps are we talking about, when discussing head temperatures on these small glow plug engines cox 1/2A's - .15 size engines anyone know?
Thanks

The anerobic gasket maker works terrific for backplates . One thing one of our club members was using in Mccoy redheads was Ultra Copper. He would dismiss the paper gasket and fill the groove within the head entirely with the Ultra Copper. He would let it set up for about 20 min and then tighten it up lightly. The following day he would snug it up. As far as I know it's still working to this day. He would use it as a base gasket as well. This would raise the compression due to it lowering the cylinder and head a few thousandths. What he did mention though was that he had to prevent the screws from now bottoming out due to the above.

Are you in search of head gaskets for the Fox? I probably have them if so. I'm not certain if they were both interchangeable as far as the Rocket.15 and the .15X. I could certainly check. But if your in need of one, I could check as I have a bunch of support parts for mine. Ken

Ken Cook wrote:              The anerobic gasket maker works terrific for backplates . One thing one of our club members was using in Mccoy redheads was Ultra Copper. He would dismiss the paper gasket and fill the groove within the head entirely with the Ultra Copper. He would let it set up for about 20 min and then tighten it up lightly. The following day he would snug it up. As far as I know it's still working to this day. He would use it as a base gasket as well. This would raise the compression due to it lowering the cylinder and head a few thousandths. What he did mention though was that he had to prevent the screws from now bottoming out due to the above.

    Are you in search of head gaskets for the Fox? I probably have them if so. I'm not certain if they were both interchangeable as far as the Rocket.15 and the .15X. I could certainly check. But if your in need of one, I could check as I have a bunch of support parts for mine. Ken

I have one fox .15 slant plug, that's in need of a head gasket, that's why I was asking about this gasket maker stuff. I do need a proper head gasket for one of my fox .15's.  Let me know if you come across one.
Thanks

I will search this evening and post my findings.

Ken Cook wrote:         I will search this evening and post my findings.

Thanks Ken

I have 2 for the slant .15 that I could send you. I don't know for certain, but if you have a steelfin Rocket .15 they're the same. Send me your address in a PM and I will get them out as soon as I can.