motor assembly

[davemvegas]

what is best to seal merc block halfs together? the red gel i have seen used does not seem to set up like rtv silicone sealer that i use on automatic transmissions and transfer cases. also do i need to put locktight on the rod bolts?i am using new ones the old bolts did have locktight on them when i tore it down.

[patchesII]

Red loctite on the rod bolts. Gel seal isn't supposed to set up. Last one I put together I used a brown sealant in a can. Can't think of the name of it right now and I'm not at home.

Do you have a manual?

[Forkin' Crazy]

The gel seal is an anaerobic sealer, so it hardens in the absence of air.

The locktite on the rod bolts is a matter of opinion. I don't use it.

[davemvegas]

no manual. but i find all the info in this great forum. i was wanting to know the reason for the gel over rvt that seems to seal anything.

[RBT]

241 on the rod bolts
perfect seal on the halfs (from merc)

[Dave Strong]

no manual. but i find all the info in this great forum. i was wanting to know the reason for the gel over rvt that seems to seal anything.

I assume you mean RTV, it can't handle fuel at ALL.
Mercs perfect seal is what used to be recomended in manuals, then they went to master gasket, they were selling a kit that had a tube of 518 and a can of 7649 primer incl. P/N 92-125642
Have used 515 and 518 with no problems but make sure to get primer as well.
271 on rods and other bolts.

Dave

[Jay Smith]

Red loctite on EVERY bolt except head bolts ( use grease on male threads and light oil on bolt flanges) reed screws I use blue on them....

I use just a smear of 518 loctite red gel seal on case halve corks and O ring areas on the seal caps top and bottom...

Jay

[Tom Foley]

241 on the rod bolts
perfect seal on the halfs (from merc)
I too am a believer in Red Loctite on acetone cleaned rod bolts at 45 Ft Lbs . Just what has worked for me is all .

As far as sealant i'm sure good old Permatex aviation sealant would work fine even though I use the Perfect Seal myself . JMHO :D

[Dave Strong]

Red loctite on EVERY bolt except head bolts ( use grease on male threads and light oil on bolt flanges) reed screws I use blue on them....

I use just a smear of 518 loctite red gel seal on case halve corks and O ring areas on the seal caps top and bottom...

Jay

Do you use the primer??

Dave

[Jay Smith]

I clean the threads with acetone...

Jay

[davemvegas]

Ok. Thanks for info. I have i just picked up a can of perfect seal and red and blue loctite now its time to start turning bolts.

[Forkin' Crazy]

Do you use the primer??

Dave

Isn't the primer the same thing as brake cleaner? That's what I use.

[Dave Strong]

Isn't the primer the same thing as brake cleaner? That's what I use.

No it's mostly acetone with a few toxic additives that I think speed the cure time.
The main thing is to be clean, acetone removes just about anything and leaves no residue. Years back when I was at GM they changed the brakekleen formula cuz it was reacting with some sealers and thread locking compounds.

Dave

[Forkin' Crazy]

Ah, OK, thanks Dave! :)

[rhickox]

Perfect Seal is what is recommended. I do Industrial Heatin and Air and we use Loctite 515 or 518 on machines that operate at 28" of vacuum at high temps with refrigerants that are a lot more potent than gasoline,alcohol or any additive.. We call it grape jelly.. I have used it a lot and had no problems. It doesn't harden but seals very good.. Plus it's free for me, and works, so why not use it? lol... I get it in a tube that fits in a caulking gun... I know a lot of others who use it also... You can get it from Grainger.....

[Jay Smith]

JMO: I wouldn't put that Mercury Perfect Seal nasty crap on ANTHING...Its ugly and a bitch to clean off ..And I don't care if it does say Mercury on it the 515-518 loctite is IMO the best sealer going well its worked for me for 15 + years and a zillion motors..

Jay

[Capt.Insane-o]

I hate that stuff.. especially when a lower unit comes in that has been slobbered to death with it.