Newbie Questions Restoring 1957 Johnson 18hp FDE-11

[fleetwin]

quote Jerry Ahrens:

I’ve always used the primer when using the gel seal, or any of the anaerobic sealer. You can actually order that stuff in a kit form, that comes with a smaller tube of the sealer and a small can of primer. I’ve always got that through Mercury Marine, but I’m sure other places have it. The surfaces must be absolutely clean before applying this product…. no grease, oil etc.
I’ll get shot at for this, but I’ve always used the old school 3m 847 for the crankcase halves of these old engines. But I always use the anaerobic stuff on modern motors.

Well, I won’t be the one that shoots you! The 3M 847 works great and is more forgiving that the gel seal when it comes to prep…This is not to say that the surfaces needn’t be properly prepped when using the 3M847, but it is more forgiving. There is nothing worse than starting up a freshly rebuilt engine only to notice an external crankcase leak….

[Mumbles]

Expanding on the primer/activator usage a bit, it’s true, the anaerobic sealers won’t cure on certain metals. Pure aluminum being one of them. Since outboard castings are alloys containing trace amounts of other metals for strength and corrosion resistance, the sealer will cure without using the primer/activator as long as the surfaces are perfectly clean down to bare metal. I’ve been told before that it’s the copper content in the aluminum which activates the anaerobic sealer. The primer/surfacer is copper based and that’s how it works. I guess what I’m saying is if you have it, use it. If not, don’t lose any sleep over it as long as the metal has been thoroughly cleaned.

The alloys used have changed over the years and early motors may have used a more pure form of aluminum, making the use of the activator necessary. Today, Mercury Marine even claims their aluminum alloy contains 10 – 20 times less copper than their competitors products. Depending on what other metals are added to the MercAlloy, using the primer/activator might be mandatory when sealing up a newer Merc.

https://www.mercurymarine.com/en/us/leg … ry/week30/

Here’s a list of metals straight from Permatex showing whether the primer/activator needs to be used or not.

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[jerry-ahrens]

quote Seakaye12:

quote Jerry Ahrens:

Why is that Jerry? Why do you suppose it works on the older but not the newer?

Well for one, the older OMC engines (for example) are smaller, and much easier to put together. When using the 3M847, you have to get the halves put together immediately after applying the product. On the larger V4 and V6 engines, the anaerobic sealer has an almost unlimited work time… no need to worry about it becoming tacky.

[chris-p]

Jerry,

I used to use 3M 847 on the crank halves as well, until I was shown why I shouldn’t.

I still use 3M 847 on my gearcases, but keep it away from the crank halves. No way could I get it together and torqued before it started to harden and clump, causing leaks.

The Loctite I now use has no fillers, and of course being anaerobic, gives you more time to torque the bolts down.

There are still a LOT of motors out on the water that I have rebuilt with the 3M 847, I just feel better using the Anaerobic stuff now. More room for error.

[fleetwin]

quote Jerry Ahrens:

quote Seakaye12:

quote Jerry Ahrens:

Why is that Jerry? Why do you suppose it works on the older but not the newer?

Well for one, the older OMC engines (for example) are smaller, and much easier to put together. When using the 3M847, you have to get the halves put together immediately after applying the product. On the larger V4 and V6 engines, the anaerobic sealer has an almost unlimited work time… no need to worry about it becoming tacky.

I guess one of the big differences I have ignored mentioning is that the older/larger engines that used the 847 also used spaghetti seal. So, it is the spaghetti seal that was doing the actual sealing, the 847 was just used to hold the spaghetti seal in place. So, I guess the old rule from OMC holds true: Any crankcases that use spaghetti seal, use only the 847 to hold it in place. Newer blocks (79 and newer on larger engines) with no spaghetti seal should use only the gel seal anerobic sealer. The comments made about the 847 drying too quickly are absolutely true, there is no way you would get a V6 crankcase torqued up before the 847 dried and shimmed the block halves apart a bit causing leaks.
On the smaller crankcases (old and new), that never used spaghetti seal, use either sealer.

[jimmy]

Good discussion on sealers, I’m definitely learning something new.

I’ve searched all over, and it looks like the only way to buy the 24163 activator is in the spray can.

As far as cleaning the surfaces, I’ve gone over them with brake cleaner and a rag. They are pretty clean, but there is some corrosion around the bearings. I imagine I shouldn’t use any abrasive on these surfaces. Anything else I should be doing?

Thanks,

[dan-in-tn]

Green Scotch Brite pad & brake clean will clean up the surface fine. The pads like you might use in the kitchen? I use them for a lot of things. Cut them up into a shape when you can use your thumb or whatever you need to get where you need.

Dan

[outboardnut]

permatex aircraft sealer
https://www.permatex.com/products/gaske … nt-liquid/

[frankr]

quote JimmY:

Good discussion on sealers, I’m definitely learning something new.

I’ve searched all over, and it looks like the only way to buy the 24163 activator is in the spray can.

As far as cleaning the surfaces, I’ve gone over them with brake cleaner and a rag. They are pretty clean, but there is some corrosion around the bearings. I imagine I shouldn’t use any abrasive on these surfaces. Anything else I should be doing?

Thanks,

Just look toward your favorite industrial supplier. I’ve been using this bottle for 2-3 years and it’s still half full. It’s amazing how little it takes. https://www.mcmaster.com/#loctite-7649/=1anz328 Buy the gallon can and you will have enough to supply the whole world for a long time. 🙂

[dan-in-tn]

FrankR; I am getting confused & I want to make sure we aren’t confusing Jim? You are advocating using this primer for bolts for Loctite, etc, right? A brush on primer would not be good for crankcase halves? You need the spray for that. Just want to make sure we are clear on that?
The gasket sealing compound outboardnut shows is correct. That is what I use & I buy it in the small bottle. It has a tendency to migrate out the top of the bottle & get real messy. If it gets thick you can rejuvenate it with 90% rubbing alcohol. Just stir it back up good. I use that on gasket or bolts where you want them to be removable (salt water). Can be cleaned up with brake clean. Doesn’t paint well at all! Same as OMC Gasket Sealing Compound or Mercury Perfect Seal.
I use a rubber based adhesive on gearcase spaghetti seal, but that’s just me? I have used 3M 847. What I use is black & more aggressive. It dries quicker, cheaper, & seems to work well. I think it is an appliqué adhesive. Been using it for years. I use the Aviation compound on all the bolt threads & body of the bolts. It prevents corrosion even though I’m not in salt water. We have a lot of lime in our water.

It just seemed we were bouncing around on many subjects (sealers) as happens. It takes a lot of different items to seal up a motor. Put that together with everybody having their favorites & it can get confusing for an admitted "Newbie"!

Another thing the activator does besides speed the setup time (which it does). You never spray the activator on the sealer only on the other side of the block. Sealer only goes on one side. It’s a catalyst action. Might be why some people have problems with it? It’s OK to let the activator dry some before you put the parts together, but be ready with all tools & fastners. You don’t want to waste any time fumbling around looking for something.

The anaerobic sealer should not be allowed to freeze! It makes it grainy. If this happens it can still be used, but now the activator is essential. We had @Loctite/Permatex visit our shop back in the day & explain this to us. We were buying the chalking gun size applicators commercial size containers since we were building so many powerheads. After I learned that fact I kept the sealer in the office at nite instead of the shop. You guys up north might consider that fact even for your small containers? Loctite/Permatex were the same company at that time owed by a parent company. I think it is the same way to this day. We could only get Permatex as Loctite was for commercial grade sales only & we weren’t a big enough company to qualify.

Dan in TN

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