Crankcase Joint-Prep and sealing

greg brillus

greg brillus

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VOC Member
redbloke1956 said:
Hi Greg, Have you used Blue Hylomar and if so, what characteristic about Threebond 1215 makes it a better product (haven't seen it before)

Kevin
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Hi kev, sorry I haven't used Hylomar before although i can imagine it's pretty good as well. If it works on aircraft engines ( where it originated form) it must be ok. Threebond is available from good auto parts outlets, and your local engine reco shop should know where to get it from....one good feature of the Threebond products is the colour match to your engine cases, making joints very neat and tidy, I have found this to be of great benefit in doing a top job, with little chance of oil leaks. First used Threebond rebuilding the engine on my 750 Bonnie years ago, never had any leaks with it...A tube of it will last a long time, and it makes gaskets all but redundant.....Cheers for now...Greg.
 
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redbloke1956

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"Hi kev, sorry I haven't used Hylomar before although i can imagine it's pretty good as well. If it works on aircraft engines ( where it originated from)"
Thanks Greg, I was in the Air Force for about a thousand years and yes we used Hylomar on everything (it was called SQ32 Rolls Royce Jointing Compound if memory serves me right) and unlike many other replacement products like Permatex it has a very long shelf life.
I will certainly give the Threebond a crack, if for no other reason than it is easily hidden.
Thanks mate.

Kevin
 
davidd

davidd

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Just so there is less confusion, there are two 1216 products. The 1216E is the formulation that Honda had made for their rocker boxes, which is also available as Hondabond HT. The 1211 is white. I think the 1215 may be more readily available in the UK than the 1216E.

David

1216A
Silicone
Gray
Gear oil resistance
1216E
Silicone
Grey
Gear oil resistance
Blow out resistance
High elongation
Fast tack time
 
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riptragle1953

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Look Guys: dammit, it's not so much what you use but how you use it. I have fitted hundreds of cases with silicone... other products would be fine.... lay a thin bead in the middle of the joint face..... attach mating part.... tighten screws until
you just see the compound start to extrude from the joint..... let cure for 24 hours.... then fully tighten. Got it?
 
davidd

davidd

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Rip,

1660bob asked specifically about Three Bond 1215 and he got a good answer. The tips were good also. I have never done what you have described and I have never had a leak, so I know there is at least one more technique that works. I have also seen too many failures caused by extruded gasket goo. I know that not one of them was a Traigle engine, which speaks for itself. I have also had to rebuild perfecly good engines (built by others) that simply had the gasket material harden and fail under pressure, so I think that selection of a good long lived liquid gasket is a worthy exercise. Anyway, I think this was a good thread.

David
 
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riptragle1953

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It makes sense given some thought. First one does not use huge amounts of stuff..... just a thin bead. When retightening the case, cover or what-ever.... what you see on the outside is equal to to inside. When cured, a solid gasket
is formed and there is no loose material to enter the engine internally! Now is the time to fully tighten..... one solid gasket that has already conformed to joint irregularities!
 
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1660bob

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Hi All, thanks for the replies, always good to get other points of view before taking the plunge!! The Threebond 1215 i have is described thus:

"high performance silicone liquid gasket,excellent LLC (??) & gear oil resistance" and "OEM" approved,
The blurb on the pack claims that it replaces/supplements gaskets, remains flexible after curing, solventless-no shrinking post cure, no acetic acid, all of which are great.
Perhaps of more interest in crankcase application is that it offers:

"Excellent resistance to thermal shock, pressure-(now thats the one thing its gonna get in a 1000cc v-twin with iffy breather system and 60yr old cases!!) shocks,vibes, gasoline/oil/LLC (I still havent figured what that is yet?)and water".

I have seen this stuff marketed as "DucatiBond" with threebond 1215 on the same pack, and believe it may also be marketed as "Yamabond", probably others too.Given that such firms would not want any warranty issues with oil leaks, and costs of repairing such, I suppose they have done their tests and research prior to endorsement, so it should be pretty good stuff.

I am trying to make the motor as oiltight as possible, as you would, but it may be a challenge- first Vincent, and i remember well the VOC Rally at the Manx Grand Prix a couple of years ago-by the end of the week there was so much oil on the pavement outside the Empress Hotel and surrounding pathways!-I saw one bike with a large ice cream container under it to catch it all when parked! It must have taken Douglas Corporation a week to clean it all up!!!!! :) , Bob.
 
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