Do you use jointing compound on a head gasket?

[marcp]

For years I have always slopped a thin smear of jointing compound (hylomar blue usually..) on both sides of head gaskets for years, never thought anything of it. When I say thin, I really mean thin.

The other day, chatting to a workmate, he pretty much told me to leave the room when he found out I did this! As far as I know all of the cars I did are going fine, 2 of them are still in the family and one has been going strong for years, did my series Landy 6 months or so ago, and its running better than ever. Infact didnt even skim the head on that, just a case of having no time to skim. Been mooching around on google tonight and sure enough, pretty much everyone says its a big no no!

So, who else uses it then, and if not, why not? Does it affect the way the gasket self seals or something?

[ChrisT]

Only once - used red hylomar - thought it might be a good idea to help it seal, until I had to do the job again the next day, without sealant.

[Copey]

Never used anything myself

[marcp]

Ooerrrr, I have been using it on all types of gaskets, copper ones, the fibre ones and the multi-layer ones, never caused me any issues. Well, got my Passat to do very very soon, so I shall try without!

[jules1200]

You shouldn't put anything on a head gasket, if the surfaces are flat it will seal, if not they need skimming. Once done it will seal, soon sealer, not ever.

[hitman]

years ago i replaced headgasket on a sapphire cosworth with a standard 2.0 ford pinto headgasket(after discussion with owner)due to genuine cosworth gaskets being mega expensive at the time,though it would benefit from a smear ov hylomar,bloke ran it for good few years after and had no problems what so ever,must admit though i hadnt used before and havnt used sealant since

[colnerov]

Hi, back in the 70s we would occasionally do decokes on a customers Vauxhall HB, the manual used to specify using Wellseal with the head gasket. We hated doing it because it was messy stuff and as my Dad used to say "it sticks like sh@t to an army blanket", could never wash it off our hands. We never had any problems with it blowing, I still use it from time to time on things that might be doubtful. Both were originally developed for Rolls Royce.

Colin

[Dez]

wellseal is a totally different kettle of fish though. fairly sure it was designed to be used as a jointing compound for engines that don't use gaskets. on a normal compression headgasket, you shouldnt need a sealant of any sort.

[welshpug]

Stag Wellseal is for metal to metal joints like cam ladders, made for rolls royce originally iirc.

[steveo3002]

don't use it myself ...also think about any stray blobs of sealer getting into the oil pick up tube

[swampy76]

Nope never used it on a headgAsket

Things line water pumps on certain cars I use a smear

[bortaf]

Sometimes, on blocks or heads where there is corosion around a water way, in fact quite a lot of head gaskets have a small bead of sealant around water ways inprgnated into the gasket, often as well around timing chain wells wheer there are not many bolts to clamp head and block together.
But never used in every curcumstances, that's a waist IMHO.

[Deleted]

If you use a good quality head gaskets and the head isn't warped there is no need to use a sealant as the gasket is designed to be the seal.
Not only is it a waste of time and money it is an even bigger waste of time if you get sealant in the water or oilways.

[Deleted]

nope never used sealent on h/gasket. done head on my mrs astra recently, the new gasket felt rather sticky.

[fordperv]

i considered wellseal once on a pita pinto engine where the block was out of true causing water to get past the gasket into an oilway, i opted against it and took the engine out and had the block skimmed

[retrowrongun]

Hairspray for the win but definately not hylomar

[surprisingskoda]

I use either hylomar red, green or blue depending on application on all the Skoda gaskets. And I'd be a fool if i refused to use them on the Austin engines. But modern stuff tends not to need it.

Fixed a corroded head with chemical metal once too. Proper traveller, me.

[trouble]

Nope, never used anything

[MrSpeedy]

Generally use nothing, but there are some applications taht call for different engines.

Some are a steel gasket and should have Wellseal applied (factory instruction) and on some engines we do which use copper gaskets, a thin smear of grease only.

Occasionally we have an engine with corroded waterways, so a carefull smear of Loctite instant gasket is applied to the water galleries only. Skimming is not an option on these 80 year old engines!

Never used Hylomar and never use anything anywhere near the oil galleries or drains (pushrod tubes etc)