Yet another sealant question..

[rullywowr]

Yeah I know, just like another oil thread.

I am looking for a good sealant for a Husky 350 to remount the upper crankcase to the plastic shell. Would Permatex motoseal work here or yamabond/homdabond? I've done metal to metal before but wondering about metal to plastic if there are any considerations. Sorry for the dumb question.

 

[fearofpavement]

The Permatex Motoseal 1 should do the job. Is there supposed to be an actual gasket there?? I think that may be the best solution.

 

[LegDeLimber]

I can't speak to the adhesive choice exactly, But cleaning and surface preparation will make or break any adhesive job.
I also would recommend a dry practice run at assembling the saw before putting any sealer on it.
Once you have the glue spread is not the time to find a problem with needing three hands or that tool I forgot about.

 

[rullywowr]

Thanks guys. I don't believe there is a gasket there between the plastic crankcase lower and the upper metal crankcase. There is a base gasket (which I am going to delete) between the upper metal crankcase and head.
It had that ****** white silicone sealant between the plastic case and the upper crankcase it but I figured I would just break down the entire saw and ensure all sealing surfaces are good. Preparation will be done right, just curious about the metal to plastic bond with these sealants. Service manual says use "silicone sealant" blah blah. Looks like motoseal will be the ticket.

 

[LegDeLimber]

Yeah, I'd avoid any silicone sealants around gasoline exposure.

 

[Mattyo]

I read somewhere else on the forum that someone liked Loctite 515. I ordered some and I'm gonna try it right now on a 350. All the the permatex silicone products say they are not gasoline resistant. So.... Loctite 515 it is.

 

[AVB]

I would not use anything that harmful to the plastic. Here I use black RTV and torque the bolts to spec. Your basically just ensuring a good seal if there is imperfections in surface area.

 

[Mattyo]

if you look at the back of black rtv silicone it says that its not gasoline resistant. I would certainly use black rtv if I thought it would be sufficient... but now I'm not sure ... just tried the 515... i'll let it set overnight and see if the saw pops tomorrow

 

[rullywowr]

Awesome. Looking forward to results

 

[farmrboy]

Loctite 515 should work too. It sees alot of use in my shop.

 

[DanS]

permatex motoseal is their gasoline resistant product.

 

[Mattyo]

nice to know... anyone know if I need to wait overnight for the 515 to set? or just start the saw now?

 

[DanS]

nice to know... anyone know if I need to wait overnight for the 515 to set? or just start the saw now?

at least 24 hours to cure.

 

[Mattyo]

sounds reasonable.... got 2 saws together tonight, can't start either ....

I don't know if i'll know if the 515 works or not until the next dismantling of the saw. ... assuming that I don't have an obvious leak immediately

 

[Big_Wood]

use loctite 518. 515 ain't the most trust worthy in solvent like (fuel) applications.

 

[Mattyo]

Well, the saw runs perfectly. Can't report anything other than that. I assume the 515 set up... hopefully no issues show up due to 515. carb adjusted fine...all is well. now I have a saw for me

 

[WadePatton]

This old thread should get at least on last bump saying that 515 is no longer recommended as it doesn't bond to plastic that great and has failed in this application. I see that Threebond 1184 and Yamabond 4 and Dirko are yet recommended and is what I'll be trying.

Bumping this because this thread may be why I bought 515 and have since returned it for refund. I wasn't checking dates on "sealant info" threads, But also the 515 is great for metal to metal sealing. Locktite's website was absolutely worthless for finding info--and the 515 didn't even have a DATA sheet.

So roll yer dice.

 

[cus_deluxe]

Ive had people tell me that 518 doesnt bomd to plastic either, but ive rebuilt a number of clamshell saws, used only 518 and have had zero issues several years later, some of them in regular tree service use.

 

[WadePatton]

... Is there supposed to be an actual gasket there?? ...

No, it's a metal to plastic machine flange fit, designed to be sealed with sealant. No gasket used by the factory. The reported sealant that Electrolux used is not even on ebay here, but it is from international sellers. Something 781 I think.

There's a video of one of the guys in this thread showing his 515 failure (that's not in this thread--in this thread is when he says hey, use this) BUT he's used 1184 since (as shown in that vid). This thread keeps kicking up when I search, so it needed updating for accurate reference sake.

I have Threebond 1184 in route. Dunn tinkin' 'bout it for a spell. The thing is that search results don't autmagically sort by date so old gets mixed with new. fin

 

[Mattyo]

Yup....use 1184 to seal the base. 518 and 515 are good for metal metal bond or metal rubber....ie...the intake boot.