Head Gasket Sealer

[itstippy]

I've got the head off my 1967 20HP Johnson FD 21R, and will soon be re-installing. Seloc's says,<br />"Place a NEW head gasket in place on the cylinder block. NEVER use automotive type head gasket sealer. The chemicals in the sealer will cause electrolytic action and eat the aluminum faster than you can get to the bank for money to buy a new cylinder block."<br />This made me chuckle, but also raised questions. I used Form-A-Gasket #2 Sealant when I put the gearcase back together. Black, tarry stuff that stays pliable. I still have most of the tube left. Is this goo considered "automotive type head gasket sealer"? Should I use something else on the head gasket? I'm in no hurry to get better acquainted with the loan officer at my bank.<br />PS Is the block aluminum and the head steel? I though gasket sealer was made for sealing gaskets. No warnings on the package. You'd think the Form-A-Gasket company would be concerned about lawsuits if their product eats engine blocks for lunch!

 

[Grant S]

Re: Head Gasket Sealer

I dont know about the warning but is it normal to use a sealant on head gaskets?

 

[Paul Moir]

Re: Head Gasket Sealer

The gasket doesn't want anything at all. It's got sealers built into it that will ooze out under heat/pressure and seal itself up fine. It's very important to retorque it after warmup/cooldown though!<br /><br />The block is aluminium, the head is aluminium, and the liners for the bores are cast iron. If you look real close at the top of the jugs, you'll be able to see where it 'turns' from iron to aluminium. A lot of the information in the Seloc manual (and others) is out of date: watch out. But I'm sure they weren't thinking of form-a-gasket but rather some Godforsaken spray on stuff they took off the shelves in 1978.<br /><br />Form-A-Gasket #2 is not the correct sealant for the crankcase, but rather 'Marpox' Sealer 1000, or 3m 'scotch-grip rubber and gasket adhesive #847'. I had some trouble a long time ago when I tried to use Permetex #3 for the purpose. Keep your eye on it. I've had sucess with Permatex Motoseal, which claims to be good for the purpose. But I only have it in a few engines running about a year now. We'll see...

 

[tvpear12]

Re: Head Gasket Sealer

nothing on the gaskets is correct. listen to your commander cadet.

 

[Solittle]

Re: Head Gasket Sealer

I understand that some head gaskets call for a sealer and some do not. I recommend that you follow the instructions in the shop manual specific for you motor. My last ones did and I used Sealer 1000.

 

[itstippy]

Re: Head Gasket Sealer

Thanks folks. I used the iBoats parts finder to order a new gasket. Found one listed that looks exactly like what I have in my hand, Sierra part number 18-2962. But it says it's for the 18HP 1959-73. Parts finder doesn't mention 20HP at all. Anyway, if you look closely at the picture the gasket has "Do Not Use Sealer" stamped right on it. <br />The iBoats gasket is out of stock, so I searched all over on the web. I found another Sierra 18-2962 with photo that looks like the right part (more $ than iBoats but in stock). This one says it's for the 1959-73 18HP and 1969-76 25HP. Again no mention of 20HP. Also says it replaces OMC part #322332. My 1967 Johnson parts catalog shows the head gasket as part #306163. Aargh! Should I go ahead and order it? Surely OMC didn't make two different gaskets that look identical in every way (at least on my 'puter monitor)?

 

[Paul Moir]

Re: Head Gasket Sealer

There's very little difference between the 18, 20 and 25 hp engines - they're all based on the same block. So they all use the same head gasket. 322332 is the correct head gasket for all three of those outboards, '59-'76. It's no doubt a superceeded number from the one indicated in your parts manual. <br />That said, Sierra 18-2962 should fit perfectly since it's a replacement for 322332. There are several online retailers that can get you it, as well as local sources (NAPA, some Carquests, your friendly neighborhood Johnson/Evinrude dealer).

 

[rodbolt]

Re: Head Gasket Sealer

hello<br /> if you use the sirrea gasket coat the surfaces with OMC gasket maker or perfect seal. its a brown sticky paint on sealant that works well. I no longer use sierra gaskets cause the steel inside the gasket has a tendancy to rust away.<br /> but either way I give them a wipe down,not a heavy coat,of perfect seal.<br /> good luck and keep posting

 

[TwoBallScrewBall]

Re: Head Gasket Sealer

I used the OMC sealer on the head gaskets on my 200 Evinrude (1997). Was it necessary?

 

[rodbolt]

Re: Head Gasket Sealer

steve<br /> I alway use it. sometimes the heat activated sealer just does not work so well. dont ever use copper coat. I saw that a time or two.

 

[DHPMARINE]

Re: Head Gasket Sealer

Steve,several years ago when the use no sealer head gaskets came out,we were told at an OMC service seminar to still use the 'brown stuff'.<br />I do.I haven't had a replaced gasket fail EVER!<br /><br />I know that is strong,but I had to say it.<br /><br />I work on a few OMC V6's,but usually spark probs.<br /><br />Don't they have "o-ring" heads?<br /><br />DHP

 

[rodbolt]

Re: Head Gasket Sealer

the 60* motors use orings the rest so far still use gaskets. I am with DP. use the brown stuff and it does not leak

 

[McGR]

Re: Head Gasket Sealer

When I replaced a head gasket on my 40hp Evinrude last year the local dealer I bought my parts from recommended coating the gasket with the OMC gasket sealer. This guy has a good reputation and his marina/family have been selling Johnsons since the beginning of time. I trust his opinion... I don't like the idea of dry gaskets anyway.

 

[walleyehed]

Re: Head Gasket Sealer

FYI, some know this, some don't.....

gasket adhesive #847'

This is the 3M P/N for OMC Type-M adhesive, or, I guess I should say "This is who made Type-M, and what it is in original form". This IS NOT, however, OMC "Gasket sealer".<br />Steve, I believe you have an Ocean pro??? That's a 90 deg version and uses a standard gasket type...You're OK with sealer.

 

[itstippy]

Re: Head Gasket Sealer

I called the Johnson dealer and they have my gasket in stock. I'll pick it up tomorrow. I'll get some OMC gasket sealer too, and use a miniscule amount of it on the head gasket. It this what you mean by "brown stuff"?<br />Next time I have the lower unit apart it sounds like I should use something other than Permatex #2 gasket sealer. I assume the Johnson dealer will have the right stuff for that too? It's two different sealer products, one for the head gasket (heat and pressure) and one for other uses, correct? I've also read in these forums that I should coat bolt threads with sealant during reassembly to facilitate later tear-downs. Don't use Permatex anti-seize? Sorry to be such a doofus, but I'm used to B&S and Tecumseh air-cooled engines - heavy hunks of iron and steel that put out a whopping 3-14 HP. These high performance aluminum alloy outboard engines that get 20HP out of something I can lift and carry around are amazing. <br />By the way, what's the difference between a late 60's 18HP and a late 60's 20HP? I know, "2 HP". But really, what makes the difference? I even see them referred to as "18/20's". I found I guy with an 18HP he's parting out that I can get parts from cheap, but I have to pay shipping. I'd rather not buy and ship parts I can't use. Thanks again everyone.

 

[rodbolt]

Re: Head Gasket Sealer

hello<br /> the omc adhesiveM now 3m super weatherstrip adhesive is a hardning permmanent adhesive. great stuff in its intended applications. I use it on seal OD's and exhaust cver gaskets when called for. sealer 1000 is very similar but thinner, no body, runs almost like water.perfect seal and gasket maker are a paint on sealent that does not dry hard. has many many uses.<br /> the oring 60* motors, I still get scared when trying to just silly cone them . but it seems to work just dont use any substace with copper. the nickle/tin antisieze is fine. mostly I just use marine grease. but I to paint the head bolt threads and shanks with perfect seal.<br /> good luck and keep posting

 

[walleyehed]

Re: Head Gasket Sealer

Rodbolt, Bombardier verified the #847 as "Type-M", it's not the weatherstrip adhesive, which hardens much more with any temp.<br />We thought there was a screw-up in the order the first time this spring we ordered Type-M, and received #847-from Bombardier-so we called..the response was "we are not going to pay to have our name put on this product anymore because we save 140,000 bucks a year by NOT putting our name on it". I knew type-M was popular, but I didn't know it was 140,000 a year popular...????

 

[TwoBallScrewBall]

Re: Head Gasket Sealer

Thanks. I'll continue to use it. Better safe than sorry I say.

 

[rodbolt]

Re: Head Gasket Sealer

type M was wonderfull stuff. the bombardier dealer I use was getting 3-m superweatherstrip adhesive from bombardier for sometime. they may have the newer brand now. is it still brown. I used the 3m yellow for years in the automotive industry so I know it works well.but the adhesive M seemed to have more body and was easier to use. either way I try to use only what is specified but in the case of head gaskets I have found if I perfect seal it it does not leak.<br /> I have not bought any in sometime now but I have 4 motors to assemble soon so its time to resupply all my sealants.

 

[Dhadley]

Re: Head Gasket Sealer

Hey Rodbolt -- interesting thing, a few years back the guys in the shop got a bit lazy - er....I mean wanted to save time - and ordered some spray sealer. I forget which it was (not Hi-Tack) but it was still the brown type stuff. It still passd the pressure check but it seems that when the motor warmed up something in the spray (propellent I'm sure) reacted with the impregnated sealer. Leaks sprang up everywhere. Luckily not past the fire ring on the head gasket and into the cylinders but all external. <br /><br />We even pulled a head gasket on a test motor, wiped it off with lacquer thinner, resealed it with the OMC Gasket Sealer (brush on) and it sealed fine.