'89 J60TLCEA block flange. Loctite Klean 'N Prime- Conflicting directions

[rebuilt]

So... the can of loctite brand primer-catalyst came yesterday. According to the instructions on the loctite 518, use "klean 'n prime on one surface only." Yet according to the directions on the can itself, "spray on both mating surfaces". The J/E manual states to spray on the "mating flange of the crankcase" step 19 page 4-21. This may seem competely anal and it might well be. I'm a pain in the butt stickler for details and haven't had a build fail yet. I've not yet built one of these, have a lot of time and $ tied up in it, and thoroughly believe that as concerns this stage of this build, I only get one chance to do this right. So.... one surface for the primer? Or two? Or does it really matter,just long as it is used. Thanks in advance, Kevin

 

[Faztbullet]

Assemble crank and pistons in block, test fit the upper half to make sure center/upper bearings are seated, wipe BOTH mating surfaces with acetone and let dry,apply primer to both side and let set and then apply 518 and install crankcase half. Install all bolts and torque to spec. Do not stop to talk or answer phone till all bolts are torqued.

 

[rebuilt]

Thanks. That sounds like real good advice. I will do just that.

 

[interalian]

I just did one side with primer and it worked great, put the bead of 518 on the un-primed side after cleaning both with acetone. Due to a problem with friction after assembly, I ended up having to separate the case the next day and every square millimeter at the interface had cured. The problem was traced to not driving the bottom seal in far enough and it was rubbing.

Make double sure any bearing alignment dowels are properly engaged in the bearings - that's what killed the rebuild the PO made on my donor block. You can see all the gory details in the link in my sig.

 

[rebuilt]

I was kinda wondering about that, wondering if 1 side primed would cure through the film of 518. I'm still gonna prime both, the spray can of klean 'n prime would probably do at least a dozen builds. Good advice on making sure the bearing dowels line up, I'm real cautious with stuff like that. I like to hand or wrench spin all rotating assemblies good and well before I button stuff up.

 

[interalian]

My thought for only doing one side with the primer was that the bead of 518 would start curing as I laid it down. A pro might be quick, a shade tree mechanic not so quick. I do know from how much acetone and elbow grease was needed to clean the joint the second time that the 518 cured very very well.