Topic: My observation on Permatex gasket cement

[kaysystems]

When I replaced the rocker cover gasket at the beginning of the riding season I used Hi-Tack spray gasket sealer. After assembly I wasn't too happy with the red that was showing around the gasket, so removed it where I could reach. Over time the red colour disappeared.
When I took the cover off this week, I found that all the sealant has disappeared and the cover separated nicely from the gasket & then the gasket simply lifted away from the head.
Don't think I'll use that stuff again.

David

[754]

Did it leak?? If not what is the problem???

[kaysystems]

It was beginning to weep a little. The gasket was damp with oil on tha sealing faces.

[mattcb350f]

I've heard of this before, It seems to evaporate over time or break down.

better than what I found this weekend.... PO strikes again

sorry to hijack, but it seemed on topic..
 Matt.

[754]

I think it should be a crime to work on bikes without knowing what SPARINGLY means....!!!

[MRieck]

 Come on...that's ART.

[mkramer1121]

And that's a smaller 4 with an o-ring seal...no way you need gasket gunk on that!

[BobbyR]

Some feel that more is more.

[HondaMan]

When I replaced the rocker cover gasket at the beginning of the riding season I used Hi-Tack spray gasket sealer. After assembly I wasn't too happy with the red that was showing around the gasket, so removed it where I could reach. Over time the red colour disappeared.
When I took the cover off this week, I found that all the sealant has disappeared and the cover separated nicely from the gasket & then the gasket simply lifted away from the head.
Don't think I'll use that stuff again.

David

My experience with Permatex silicons is like that, too. And, like the ugly picture above.

All my experience:

1. If you can find FelCoBond, use it wherever there is a gasket on these bikes.
2. Second choice: Hondabond/Yamabond on gaskets (you must use this stuff on the crankcases or the bearings will be too loose).
.
.
.
Last choice: Permatex.

Now, for old 1960s Fords:
1. Permatex.
2. Nothin else works... 

[mark]

That picture looks like a case of 'substance abuse'. Expect to find the rest of it in the oil screen.
There's enough silly goo there for about ten old Ford engines.
Leave the tube in the toolbox when working on a bike.

Plain old Contact Cement is the stuff if you can't find FelCoBond(or hardware store is closer than auto store). Either product will hold a gasket on without hardening.

I've had good results on split case joints with the brown liquid 'Aviation' Permatex. The rear main cap on the Ford gets a smear too.

Spray Tack works ok on flat gaskets but really isn't worth it. About 2% of the can goes on gaskets, the rest goes everywhere else then dries up and gets tossed.

3M Weatherstrip Adhesive can hold a gasket but sets hard. Torque the bolts before the stuff dries or else. Yes, I learned that the wrong way.


Happy trails.

[Trevor from Warragul]

The cam looks knackered...

[ChopperCharles]

I bought a V65 Magna parts bike a few years back that was a non runner. Cranked over on the starter it sounded like a bomb was going off... just for #$%*s and giggles I diassembled the engine... the PO had used silicone gasket everywhere. EVERYwhere. Valve covers, clutch cover, alternator cover, everywhere there was a gasket that needed to be replaced, there was gobs of silicone sealant. It blocked two of the four oil passages to the front cams and all of the passages to the rear cams, then clogged the oil pump intake screen and spun all the main bearings AND all the rod bearings. There wasn't a single usable bearing in the entire engine.

Silicone sealant is terrible stuff... it should never, ever be used inside an engine.

Charles.

[MRieck]

Come on...that's ART.

 Heres some more ART. I came across it on a Kawasaki board that I frequent.

http://oldkawman.com

   Click on the "Oil Cooler Fabrication" link on the left side and check out the Permatex on that engine. Its everywhere!!! I can only imagine that there is equal amount of sealer on the inside of the gasket surfaces also.

DG

To cheap to buy gaskets I'd guess God that is awful.

[S-Dog]

I migrated over to the "other" pics.... not too bad. 

[dusterdude]

use indian head,good stuff

[754]

I never had a problem with silicone, but I use it sparingly..smeared on the gasket very thinly..

And I know what sparingly means!!

I dont think I ever had any squwooge off into a motor..

.(well not since I was 17!!)

[Walt]

I'm getting ready to replace a head gasket on a 400F (my first time doing a head gasket) Should I use something like Honda bond/Yamaha bond with a brand new gasket? Sparingly of course.

Thanks,
Walt

[TwoTired]

I fail to see the need for any gasket sealer on the head gasket.  Well, perhaps as insurance around the cam chain tunnel area.  But, there are highly conformant rubber bits to seal oil passageways, that generally work best when the applied to a clean surface so as not to interfere with their conforming properties.
The cylinder seal is subject to high heat and pressure that a sealer is not going to help.  There are no water jackets to seal on the SOHC4.

Perhaps some of the master engine builders can explain.  Is there some trade off between cleaning the surfaces and gasket sealer that binds regardless of surface prep?

Certainly, if you are reusing old gaskets, they are likely to need help in re-establishing a seal.  Gasket goop IS cheaper, I suppose.  But, that stuff is for shyster POs IMO, in order to create grief for current owners.

Okay, sometimes you need something to tack the gasket in place during assembly.  But, as seal insurance?

Discussion?

Cheers,

[ChopperCharles]

Head gaskets should be assembled dry and clean! Clean off the old gasket material, and wipe both surfaces with alcohol to clean off any oil residue before assembly.

Charles.

[754]

I question sticking them up as well.. like after all there are dowels , and we dont assemble upside down.. not me anyway!!

 A long time ago my mechanic buddy said watch this, took a punch and very lightly dimpled 3 or 4 little marks around the oilcarrying studs.. said they bit better and never leaked..

[MoTo-BunnY]

I've had good results on split case joints with the brown liquid 'Aviation' Permatex. The rear main cap on the Ford gets a smear too.

3M Weatherstrip Adhesive can hold a gasket but sets hard. Torque the bolts before the stuff dries or else. Yes, I learned that the wrong way.

The only Permatex I use is the 'Aviation' stuff (Permatex 3H) - its a habit that carried over from my air-cooled VW days. Its pretty amazing stuff - super high heat resistance and seals really well. Its kinda weird in that it doesn't seem to ever fully dry. A really light film on about anything seals it good. Use alcohol solvent to thin or for cleanup (when still wet - once dry, nothing works) as nothing else seems to touch it. 

The 3M weatherstrip stuff is also really handy. Its like rubber cement on steroids! Its nearly identical to what I used when I worked at a shoe/leather repair place years ago. For leather, fabric, etc - a thin coat on both surfaces, let them dry, then stick it together and it won't be coming apart anytime soon. A lot of VW peeps use it on one side of the valve cover gaskets to help seal it but allow the cover to still be opened easily for valve adjustments.

[MRieck]

I fail to see the need for any gasket sealer on the head gasket.  Well, perhaps as insurance around the cam chain tunnel area.  But, there are highly conformant rubber bits to seal oil passageways, that generally work best when the applied to a clean surface so as not to interfere with their conforming properties.
The cylinder seal is subject to high heat and pressure that a sealer is not going to help.  There are no water jackets to seal on the SOHC4.

Perhaps some of the master engine builders can explain.  Is there some trade off between cleaning the surfaces and gasket sealer that binds regardless of surface prep?

Certainly, if you are reusing old gaskets, they are likely to need help in re-establishing a seal.  Gasket goop IS cheaper, I suppose.  But, that stuff is for shyster POs IMO, in order to create grief for current owners.

Okay, sometimes you need something to tack the gasket in place during assembly.  But, as seal insurance?

Discussion?

Cheers,

Earlier 750's don't have the the oil return dowels/rubber washers but the OEM head gaskets had copper sealing rings built into the gasket. You can't get those gaskets anymore and they are no good for an 836 kit etc. As a side note, the Cometic CFM-20 head gasket doesn't have oil return holes large enough to accomodate the sealing rings. I've always used a small amount of Hylomar around the tunnel, return passages and feed areas. Decked cylinders/milled heads, clean surfaces, heavy duty studs and replacing the 4 hex/phillip bolts with studs is a good way to prevent leaks too. I've also seen OEM replacement paper gaskets come from the factory with 1104 sealer applied to sections.
  I use a very thin coat of spray Hylomar on most paper gaskets on the 750 as the surfaces are not "factory fresh" after 30 or 35 years. There are many small scratches, gouges etc that invite seeping, weeping or straight out leaks. I hate oil leaks.
  As for silicone sealents....all the major Japanese factories use silicone( applied by robot) to seal the engine cases. Permatex makes several good types. It's like booze...used within reason it's great.

[MRieck]

I have a bunch of magazine articles for the Kaw 900's from the '70's and they suggest (drum roll please) Rustoleum silver paint for sealing the head gasket.
 Anyone else ever heard of this?
 DG

Yes but it was for cars

[HondaMan]

I have a bunch of magazine articles for the Kaw 900's from the '70's and they suggest (drum roll please) Rustoleum silver paint for sealing the head gasket.
 Anyone else ever heard of this?
 DG

Harleys used it during the 1970s, too.
We also used it to seal pinhole casting leaks in cases: spray some in a small cup and wipe it over the pinhole when the engine is warm. Lasts for several years.

[kaysystems]

Earlier 750's don't have the the oil return dowels/rubber washers but the OEM head gaskets had copper sealing rings built into the gasket. You can't get those gaskets anymore and they are no good for an 836 kit etc. As a side note, the Cometic CFM-20 head gasket doesn't have oil return holes large enough to accomodate the sealing rings. I've always used a small amount of Hylomar around the tunnel, return passages and feed areas. Decked cylinders/milled heads, clean surfaces, heavy duty studs and replacing the 4 hex/phillip bolts with studs is a good way to prevent leaks too. I've also seen OEM replacement paper gaskets come from the factory with 1104 sealer applied to sections.
  I use a very thin coat of spray Hylomar on most paper gaskets on the 750 as the surfaces are not "factory fresh" after 30 or 35 years. There are many small scratches, gouges etc that invite seeping, weeping or straight out leaks. I hate oil leaks.
  As for silicone sealents....all the major Japanese factories use silicone( applied by robot) to seal the engine cases. Permatex makes several good types. It's like booze...used within reason it's great.

One of the Service bulletins for the early 750s suggests the use of 'o' rings around all the studs. That really works great. Make sure they are the correct size.

David