Gasket sealants

[premuda01]

Hi Everyone, was given a 039 non runner, I have a passion for repairing things, anything, love small engines - its a hobby. And i dont like the chuck repairable stuff away culture. So this was a piston failure. So ordered a new piston, surprised how cheap. Then I check out the right sealant to use on the cylinder to crankcase, loctite 518 seems to be the consensus. Your kidding me right 37 quid!!!!!, thats 3 times what i paid for the piston! I cant seem to buy it in the UK in small quantities. UK guys, surely i can find something cheaper. I've been on the Halfords site. But nothing there tells me if its the right stuff or not! Can you advise?

 

[user 122190]

Those 2 pieces are usually well machined and tight fitting. You can get by with most sealants. Allow to get tacky, and torque evenly and firmly.

 

[Little Al]

Hi Everyone, was given a 039 non runner, I have a passion for repairing things, anything, love small engines - its a hobby. And i dont like the chuck repairable stuff away culture. So this was a piston failure. So ordered a new piston, surprised how cheap. Then I check out the right sealant to use on the cylinder to crankcase, loctite 518 seems to be the consensus. Your kidding me right 37 quid!!!!!, thats 3 times what i paid for the piston! I cant seem to buy it in the UK in small quantities. UK guys, surely i can find something cheaper. I've been on the Halfords site. But nothing there tells me if its the right stuff or not! Can you advise?

Two of the best sealing compounds are Hylomar (blue) & Wellseal( stinky& ****** brown developed by RR for theirWW2 Merlin aero engine & still one of the best ) available Ebay or was

 

[premuda01]

ok thanks guys - i was concerned about the effects of petrol in the mix on the sealant. Recall many years ago a friend using the wrong sealant on a moped carb. It ruined his day!

 

[jrs_diesel]

I just bought a tube of 518 to reseal a clamshell crankcase, and that cost me $16 on this side of the pond. Doing the currency conversion, £37 = $47, that's pretty expensive

I will say that the 518 does work quite well

518 is an anaerobic sealant, it will cure in the absence of air, such as when you reassemble the crankcase. Any of it that squeezes out, will stay liquid. When it's outside the crankcase, you can simply wipe it off. On the inside of the crankcase, the fuel mix will wash it out on the first run and causes no harm to crankshaft, piston, and bearings.

 

[Nwpa]

Some others are Permatex motoseal or Honda bond.

 

[rwoods]

518 is what I use, but Permatex recommends using its Surface Prep as well. No one locally stocks the Surface Prep. Online prices are all over the lot from $15 to over $25. This could get real expensive for our UK friend.

Ron

 

[premuda01]

yes jls_diesal maybe we should get into the 518 smuggling game - i think the issue is getting hold of small tubes, they only do large ones. If your using it to do a car cylinder head that makes sense. I see them on US sites.

 

[premuda01]

https://www.qualitybearingsonline.c..._p8f1UFaYRzUtapUeEFz5OSpw6cWOc_BoCBQkQAvD_BwE

 

[president]

(stihl) dirko,dealer stuff

 

[Canyon Angler]

Not to hijack the thread, but I just bought my first Huztl/Farmertec kit, for a 361.

The gasket sealants I have are:
1. Hylomar Blue
2. Permatex Aviation Form-A-Gasket No. 3 – A brown, sticky goo that smells like booze and I think resembles the old Indian Head stuff.

The Permatex is good for a continuous temperature up to 400°F.

Will these two sealants cover everything I need to assemble a 361 from a kit?

Which one should I use for
- cylinder to case?
- case half to case half?

Thanks for any help.

 

[Little Al]

Never dealt with the Permatex but Hylomar should cover all your requirements

 

[blueknobbuck]

i used permatex 51031, i believe similar to loctite 510, permatex51831 similar to loctite 518

 

[ammoaddict]

I have only used motoseal, but I would think any brand would work as long as it's gasoline resistant.

Sent from my Moto G (4) using Tapatalk

 

[Canyon Angler]

What kind of temperatures do you think can be expected on a chainsaw cylinder and case? I never found a "max temperature" for the Hylomar, and I think the Dirko HT was rated to 450 or 500°F and the Permatex Aviation stuff specs it at 400° continuous...

Somewhere it seems like I saw someone used an IR thermometer on a saw cylinder, and getting it much above 350 or 375° was almost impossible because the heat dissipated so fast...aluminum conducts heat away like crazy. I know from tig welding it, you need to blast the piss out of aluminum with current to melt it...

 

[jrs_diesel]

The hottest areas of the cylinder are going to be the around the exhaust port and the upper end of the cylinder.

The intake and lower crankcase/clamshell will be the coolest.