Sealing compound for joining the crankcase halfs

Hi Ken,

I think you are fine, the 40 bucks applies only if you choose to ship by air. The description calls for the extra 40 "WHEN" shipped by air. Ups will take it ground for 13 and change. It is the U.S. postal service that won't. If you look at the HOA bit on the website (I do not have the catalogue) the comma is the key, it is "hazardous, air only" that means hazardous for air shipments only. Those regs are commonly worded like that so they can cram a lot of info into a single page.

Kind of like the old joke about how important punctuation is, as in "Let's eat, Grandma" is a whole lot different than "Let's eat Grandma.

At least that is how it looks to me, if they try to stick you with the 40 you should be able to cancel if they a straight up kind of outfit.

lcrken said:

Well, rwalker28 piqued my interest, so I've ordered a tube each of Wellseal and Hylomar Blue (I'm almost out of it anyhow) from Pegasus, and the receipt shows the cost of shipping UPS ground, and no mention of the $40 HAO hazardous material fee. However, their web site and catalog still say both materials are HAO and will require the $40 fee, and must be shipped UPS air. AND, the receipt that shows just the $13 UPS ground fee calls the total cost an "Estimated" total. I fully expect to hear from them, with the additional $40 charge added, at which point I would hopefully be able to cancel my order. The last time I bought a tube of Hylomar Blue, I had to have the local NAPA store order it, but at least there were no extra fees for shipping, HAO, or anything else. I'll report on whether the order goes through.

Ken

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When we assemble engine cases they are seldom together for a lifetime, i.e., they ultimately end up coming apart to facilitate access to some other subassembly that has failed or is in the process of failing. And although our primary objective is a leak-free engine, it is the disassembly and subsequent clean-up process that I am curious about now.

Regarding disassembly, I know that several silicone-based sealants can present a challenge when it comes time to separate the sealed joint. Once separated, silicone sealants can generally be cleaned-up relatively easily with common spirits and perseverance.

I have no experience with the Yamabond, Hondabond, Threebond genre of sealants, so am curious to hear feedback from end-users on how these synthetic rubber-based sealants are for disassembly and especially post-use clean-up.

Likewise I lack experience with the rosin ester based sealants, e.g., Wellseal, Loctite Aviation Gasket Seal, etc and am equally curious about end-user experiences with disassembly and clean-up of surfaces sealed with these materials.

Because some of these materials are delivered in chlorinated solvents (small molecules that are very good solvents), are resistance to oil, gas, and most automotive fluids, it would follow that they might likewise be quite resistant to many common solvents we might use in an attempt to dissolve/remove them. Thus I am especially curious to hear how people deal with their removal.

Thanks for your feedback.

I don't have current experience with Nortons, but on 1970s BMWs, the sealant of choice for the pesky crankcase to cylinder case joint has changed over the years from Hylomar to the Dreibond/hondabond/yamabond range of sealants. These sealants work to properly seal the joint, whereas with Hylomar sealant, the joint will start to mist oil, especially if the bike is used hard. When my Norton gets to the stage of needing sealant then I will go down the Dreibond route.

iMHO etcetera

Charles

Slick[/quote]
Thanks JimNH. I reinforce Slick's sentiment. Excellent resource and well worth paying the price for membership!
The first few pages re products and applications are brilliant - I'd not heard of Dow Corning "MOLYKOTE® G-N METAL ASSEMBLY PASTE" for cam assembly and bedding-in.
I especially like that the document is current i.e. 21st century revised in 2014.
Ta.[/quote]

Funny about the 21st century comment. When I last used the recommendation list it was well back in the last century. Continental Motors was them known as Teledyne Continental, TCM; I see the name has changed yet again.

Thanks for reading it through and bringing the DC MOLYKOTE to my attention. My latest need for a cam lube was my MG TF engine, one know for beating up lobes and lifters. I used a Permatex product but it was not a moly paste; time will tell if it survived break-in. My experience as an aircraft mechanic made me a believer in their recommendations so next time I'll look at the DC product.

As for MC and other cases not aircraft, I'll continue to use Yamahondasuzukibond as I've had good luck with it and, when you do get it apart it cleans up with solvent quite easily.

Loctite 518, a modern anaerobic sealant that works great on aluminum. I haven't tried it on my Norton cases but I've used it on my BMW cylinders with excellent results.

I use 518 for my timing cover where there is a gasket, use 515 for metal to metal surfaces, like the CC halves, TTI gearbox etc.
Regards Mike

lcrken said:

Well, rwalker28 piqued my interest, so I've ordered a tube each of Wellseal and Hylomar Blue (I'm almost out of it anyhow) from Pegasus, and the receipt shows the cost of shipping UPS ground, and no mention of the $40 HAO hazardous material fee. However, their web site and catalog still say both materials are HAO and will require the $40 fee, and must be shipped UPS air. AND, the receipt that shows just the $13 UPS ground fee calls the total cost an "Estimated" total. I fully expect to hear from them, with the additional $40 charge added, at which point I would hopefully be able to cancel my order. The last time I bought a tube of Hylomar Blue, I had to have the local NAPA store order it, but at least there were no extra fees for shipping, HAO, or anything else. I'll report on whether the order goes through.

Ken

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Just to wrap this up, the Wellseal and Hylomar Blue both arrived today with no $40 fee added. So if you want either one in the US, Pegasus is a good source. It's $21.49 for a 100g tube of Hylomar, and $21.99 for a 100 ml tube of Wellseal. Pricey, but a tube goes a long ways.

Ken

I was just thinking , what really starts the crankcase halves from sealing after time is something called "Shuffling". So the 3 bolts of the sub-frame to crankcase need to be checked for tightness periodically as they loosen up ,not found in the manuals. The top uppermost one seems to loosen up most from this. :wink:

Brooking 850 said:

I use 518 for my timing cover where there is a gasket, use 515 for metal to metal surfaces, like the CC halves, TTI gearbox etc.
Regards Mike

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I have used Loctite 515 (and its previous versions) for crankcase joints and to replace base gaskets for cylinder to case joints for many years. A secondary benefit is if any excess gets squeezed to the inside, it will dissolve in the oil rather than form little beads which either collect in the sludge trap or find there way to bearing surfaces.

I stopped using Hylomar dozens of years ago as I realized it got dissolved by my favourite motor oil, Castrol RS 10 W 60. For the last 15 years I used Silicone Omnivisc 1050 with perfect results.

Why would a motor oil dissolve a sealant made for engines ? I just don't much trust silicones for this application . Bathtubs , aquariums etc. , for sure.

Hylomar is designed so that any excess that typically gets squeezed out on assembly of the engine is dissolved by motor oil and does not black oil passages, whereas random bits of hard silicone could get carried away to places they might do damage.

That's the theory anyway, I prefer the Yama/Honda/drei/ bond type sealants as I think that they do a better job than Hylomar.

Seems as I picked up my 4 oz of Hylomar at a local auto store for about $15, but that was in 05, so it might be $20 by now. I think I called them and they ordered it for me. But I think I'd use something easier to work with next time.

Here is my experiance. I have used Wellseal, Locktite 515 and Yama/Honda/threebond on cases over the years.

The Locktite and Wellseal sealed up good to begin with but after a few years the cases seemed to leak slightly at the joints.

The Yamabond seal has been permanent. The downside is it makes the cases tough to get back apart after a year or so.

So on streetbikes that I don't plan on disassembling regularly I use Yamabond.

On racebikes that come apart regularly I use Locktite 515. I might use Wellseal but it is tougher to clean up after disassembly than Locktite. Jim

COMNOZ do you apply the Yamabond to both case halves or only one before assembly?

Thanks

thunderbolt said:

COMNOZ do you apply the Yamabond to both case halves or only one before assembly?

Thanks

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I apply it to both sides with a small firm brush. [a flux brush] Thick enough that it looks smooth. Then assemble it immediately. Jim

comnoz said:

thunderbolt said:

COMNOZ do you apply the Yamabond to both case halves or only one before assembly?

Thanks

Click to expand...

I apply it to both sides with a small firm brush. [a flux brush] Thick enough that it looks smooth. Then assemble it immediately. Jim

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Thanks Jim.