Gel seal (Loctite 518) with primer?

[interalian]

Getting ready to button up the crank case. The Loctite 518 card says to use "Kleen n Prime" on one surface, but I've seen numerous cases where none was used. Haven't found any locally - should I go ahead and assemble without?

 

[flyingscott]

I just cleaned the 2 halves with a degreaser first then acetone to make sure they are perfectly clean. I then painted both halves with the 518 and put it together.

 

[rothfm]

Same as Flyingscott. Have never used primer, clean several times, then acetone. Havent had any issues.

You dont want to do it again, so be sure to use fresh 518 if any question.

 

[interalian]

Good info. After calling a couple of other places, I was able to grab a can of KnP. My tube of 518 is new. And you're right, I don't want to be doing this again until this motor wears out in another 20 years.

 

[interalian]

Before I button it up, I haven't seen a torque value for the 1/4-20 crank case bolts. The mains are 18-20 lb/ft. Can't find it specifically in the OMC Service Manual or in the Seloc online at boatinfo.no aside from the generic 5-7 lb/ft for 1/4" bolts.

On that topic, the Seloc online shows conrod bolt torques at 30 lb/ft for most but shows 42 lb/ft for the 140 and some others. The OMC book just says 30 lb/ft (40-42Nm) for all.

 

[Faztbullet]

I always use primer as it causes sealer to set faster(15-30 minutes), if you don't use it it take about 48 hours to cure. Ypour s is a crossflow so rods are 30ft lbs in 3 stages(10-20-30) as 42n ft lbs are for looper motors. I torque all 1/4-20 bolts to 22 inch lbs.

 

[interalian]

Thanks!

On the primer, I hear you. I got some 515 to fill the minor chatter voids on the center bearing (as suggested by one of the gurus here (can't remember who)) and put together a sample electrial plate and metal strap a couple of weeks ago as a test. It never cured at all. I put a spritz of Kleen n Prime on with some fresh 515 and it cured firn in a half hour.

 

[jakedaawg]

Must be nice to have a parts store that carries the primers. I have always wanted to try them but I live to far in the boonies to get it I guess.

 

[flyingscott]

That is a good piece of info My rebuilds usually sit at least 48 hrs before going to the water so for me it's okay.

 

[F_R]

Locktite anaerobic products cure in the absence of air. But the cure rate is seriously affected by what kind of metal it is in contact with. It cures extremely fast if in contact with copper or brass, kind of slow on aluminum, and hardly at all on stainless steel. The metal acts as a catalyst. As far as I can tell, the primer has a copper content. Yeah, I know, right away somebody is going to raise the electrolysis issue. Not to worry, the primer only contains trace amounts of copper. Whatever the secret is, it sure does work.

 

[F_R]

Heh, I just did some study-up. Kleen n Prime contains acetone, isobutane, and 2-ethylhexanoic acid. 2-Ethylhexanoic acid is the organic compound with the formula CH[SUB]3[/SUB](CH[SUB]2[/SUB])[SUB]3[/SUB]CH(C[SUB]2[/SUB]H[SUB]5[/SUB])CO[SUB]2[/SUB]H. Now all we need is a chemist to tell us what that is. But it does say it is used as a catalyst.