Silicone
 

Getting close to putting my M18 together. Service manual calls for calls for a silicone sealant/adhesive between the cylinders and the crankcase. Listed are Loctite 593, 594,595 and several Permatex 6 series silicones. Also some
GE and Dow products but I doubt they can be purchased locally. McMaster has the 593, just wondering if anything I already have would work--I have some Permatex ultra-black. I've heard of products put out by Yamaha, Honda, and have even used one from Stihl to put a chainsaw back together. Considering the info in the service manual is probably 25 years old, is there a more common/advanced silicone material you folks would prefer that is available at most auto stores?

Don't get hung up on it John. Just get whatever silicone from a parts store and put it back together. Black permatex is fine.

The Hondabond and Yamabond that's been talked about is normally used to seal aluminum cases together where there's no gasket and works amazing. Im too lazy to look but is there a gasket in this area?

We had an order going in to McMaster at work today so I just added a tube of 593. For $6 its cheaper than what a tube of ultra-black sells for locally. I'll just give the boss the $ and have it tomorrow.

The aftermarket gasket set I ordered may actually have gaskets for this, but the engine certainly did not and the service manual is quite specific on what, where and how much sealant to use.

Wonder why some manufacturers are specifying certain sealants, instead of just saying to get a high end oil resistant silicone? The Stihl silicone I used last year was for the crankcase halves on a saw I was rebuilding. Don't know if Stihl sells it to the public, had a friend that got it while working in a saw shop. Come to think of it he gave me a huge tube of some special sealant/silicone put out by Navistar (I think)--his next gig was a heavy truck/equip. mechanic.

ANY sealant, that takes LOTS of labor to use,, is worth testing before use.

I purchased some silicone made to seal gutter joints,,, it never cured.
It was from a defective batch,,, and they knew it was defective before I called.

The product was not expired,, in fact it was 3 months old.

The company, after two emails, and a phone call,,, refunded the product cost PLUS the labor to replace the silicone.

I will test before use,,, now.

Agreed! This happened to me a few times, using silicone caulking for windows and/or tile and bath. Sometimes I've had tubes where the caulking where so watery(thin viscosity) that the bead of silicone would drip/run off.

It is strongly recommended to use the high dollar ,thick silicone on crankcase halves etc ,that area is only designed to use a minimal amount of sealant ,with the heat it takes . Mitsu uses it a lot on the Mivec engines we liked the Dow brand