When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi.
when installing plain gaskets, seen some using Permatex "form-a-gasket" ; some using nothing, some using silicone on one side, or in both sides, some using grease on the gasket. Seems everyone has their method.
What is the proper/correct way for installing a plain inlet manifold, a front cover engine, a water pump gaskets ? The term "form-a-gasket" suggests that the compound is meant to replace the gasket as if you 'do not have a gasket to install' nor to use as a gasket adherent. What is reallly correct, how is it done at an engine assembly plant ?
Here's what I think. On flat smooth surfaces, like at an assembly plant, plain gaskets are used without anything added. The exception is at sharp corners or where two metal parts meet, silicon is placed on the line to prevent oil seepage. Some joints might prove to be difficult to seal or stay sealed, so the engineer specifies a coating. On pitted surfaces, mechanics place a skim coat to help seal better. Sometimes grease is used to hold a gasket in place and promote swelling of a paper gasket to help seal a joint. The "right" way is the one that forms a good enough seal. If the joint is routinely dis-assembled (think racing, or a plan to go back in later), then a simple gasket prevents the need for difficult cleaning of the surfaces, compared to using chemical skim coats, so a small leak might be acceptable there. The Land Rover Workshop Manuals are pretty good about spelling out the details of gasket installation and the types of chemicals to use.
a light coat of halomar blue is what I used on my water pumps and front cover. 1-2mm bead is all. As you wrote, everyone has their preferences and reasons (some good, some not)
Engineer here with 35 years experience designing all manner of equipment with gaskets. What we do in an ideal factory setting is quite different from what you do in a workshop. In a factory setting we are using freshly machined surfaces with trained technicians and ideal work piece orientation. In a workshop you using less than ideal orientation, work pieces that have been through multiple thermal cycles and already had gaskets applied and removed several times, with questionable mating services. Also having been responsible for maintenance over several decades and practiced it myself with all manner of racing Vehicles as well as the Land Rovers I have found the most ideal approach is to apply a thin coat of RTV to thoroughly cleaned surfaces. Install the two meeting components while the RTV is still wet and tacky but do not torque the bolts only apply enough mating pressure to allow the RTV to touch the two surfaces so that it bonds. Allow to cure 24 hours before torquing bolts. This lets the RTV fully cure and creates a sealing bead that is bonded to both surfaces and will seal all leaks.
...the most ideal approach is to apply a thin coat of RTV to thoroughly cleaned surfaces. Install the two meeting components while the RTV is still wet and tacky but do not torque the bolts only apply enough mating pressure to allow the RTV to touch the two surfaces so that it bonds. Allow to cure 24 hours before torquing bolts. This lets the RTV fully cure and creates a sealing bead that is bonded to both surfaces and will seal all leaks.
Thank you. Then, if a gasket factory coats thin RTV allowed to cure; it would be the ideal process allowing instant assembly at the workshop with no wait to torque, right ?
Maybe a couple of days late here. The only place that I've seen "(Aviation) Form a Gasket" is when assembling the crankcase halves on light aircraft piston engines. When doing this, you also install a long piece of thread (I don't remember what kind of thread) around the whole sealing surface. I don't see a place for it on our vehicles. It's a very old product and I think that the name is misleading in this day and age.
Maybe a couple of days late here. The only place that I've seen "(Aviation) Form a Gasket" is when assembling the crankcase halves on light aircraft piston engines. When doing this, you also install a long piece of thread (I don't remember what kind of thread) around the whole sealing surface. I don't see a place for it on our vehicles. It's a very old product and I think that the name is misleading in this day and age.
it's like a single strand silk thread, I've seen that on the socials with old 911 motors.
Thank you. Then, if a gasket factory coats thin RTV allowed to cure; it would be the ideal process allowing instant assembly at the workshop with no wait to torque, right ?
Part of workshop issue is less than perfect sealing surfaces. That factory thin rtv does not fill surface imperfections.
I use this Permatex Aviation gasket sealant on most sealing surfaces on the Disco and L322. By this age, they've had so many gaskets removed, scraped off, etc, so this will help fill those tiny imperfections to help the gasket perform. Best part of it, it cleans up with rubbing alcohol extremely easily, so next time you replace a water pump gasket, you won't be bent over for hours carefully scraping off the old material.
The sequence for something like the water pump gasket is: clean gasket surfaces with rubbing alcohol, use a small paint brush to paint this stuff on both sealing surfaces, then place the gasket. So it's kind of a gasket sandwich. Let settle for 24 hours and you're good to go.
Gaskets placement...
