Are there any professional mechanics that actually let RTV cure for 24 hours?
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Permatex now has at least 6 types of Right Stuff. They are black, grey and red in both 1 minute and 90 minute cure times.
I generally try to stack my work load so that if something is going back together with RTV its my last job of the day that way it can sit overnight before it sees oil.
The Right Stuff comes in 1 minute and 90 minute products. Directions for the 1 minute are: Apply continuous bead to one surface. Assemble parts within 5 minutes. Tighten to torque specifications. Return to service. Recommended applications: Oil pans, timing covers, transmission pans, differential covers.
Obviously, some timing covers and oil pans are large and/or complex shapes for which the 1 minute product is not suitable. If I ever need to reseal the timing cover (a large complex shape) on my 5th gen 4Runner, I'll use the recommended Toyota sealant.
Shops that perform frequent sealant repairs probably have their favorite brand and type to use in a given situation. They don't want a comeback, or they may not want a vehicle to sit for a day/overnight waiting for the sealant to cure.
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Here are the instructions for Ultra Grey. It has two different versions depending if you are using the “ Power Bead” applicator. The “Power Bead” version asks for the pause prior to torquing the the bolts, much like Ultra Black. Using the regular application without the “ Power Bead “ you torque the bolts fully right away. I gather that the “ Power Bead” typically gives you a larger bead or else there is something different about the formulation.
Years ago the Ultra Grey Instructions asked for the pause prior to torquing, even without the ”Power Bead”. I phoned the tech line once to mention the product did not have the initial cure in the two hours recommended prior to torquing and they said to wait longer. The product wanted to ooze as I started to apply torque. They said the cure time depended on moisture in the air. I was in a low humidity environment so it was taking longer. I waited another hour and it set properly. I then torqued the bolts without problems. When they say “ wait at least two hours “, they really mean wait long enough that when you start torquing it no longer oozes. Always read the back of the tube to get the latest instructions and realize more time to cure is required in the dry western States.
Years ago the Ultra Grey Instructions asked for the pause prior to torquing, even without the ”Power Bead”. I phoned the tech line once to mention the product did not have the initial cure in the two hours recommended prior to torquing and they said to wait longer. The product wanted to ooze as I started to apply torque. They said the cure time depended on moisture in the air. I was in a low humidity environment so it was taking longer. I waited another hour and it set properly. I then torqued the bolts without problems. When they say “ wait at least two hours “, they really mean wait long enough that when you start torquing it no longer oozes. Always read the back of the tube to get the latest instructions and realize more time to cure is required in the dry western States.
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Permatex now has a website selection guide where you answer simple questions and it guides you to their recommendation. Here is a screen shot on the question on curing time. If you need less than 24 hours cure time it guides you to the “ Right Suff” and shows both the One Minute and 90 Minute versions.
That's why I would use a gasket if available.
Just for fun, I went through the iterations, checking off “Yes, I want a fast cure under 24 hours”. For the oil pan, and timing cover The Right Stuff Black was recommended. For the thermostat housing, valve cover, and intake manifold The Right Stuff Grey was recommended. Black seems to have an enhanced resistance to motor oil. Also, these RTVs will become redundant as most newer vehicles are now going to pre-molded high tech gaskets.
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I’m OK with all that but Permatex has Ultra Black, Optimum Black and now Right Stuff Black, all specially designed for motor oil resistance.
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If it was the end of the day I have a few times, but a lot of times I have done like you said, "let it set an hour with the bolts finger tight before torquing" But a little more than finger tight, I'd tighten with a wrench or ratchet till the RTV started to spread out a bit, then let it set for an hour or so, or sometimes even overnight, and torque it the next day, I've had good results with that method.
For a rear end, it doesn't matter. You'll never get all of the oil out of it, so even if you want it to sit overnight, oil will most likely still be be at the very bottom of the cover.
Yes. The Right Stuff and it goes back together immediately. I’ve tried some of the other sap that needs hours before assembly and it seems to crush, squeeze out, and generally make a questionable seal when the parts are reassembled. I like the quick seal stuff. It conforms to all the voids etc and then cures.
Yea, Toyota states don’t start the engine or fill fluids for 2 hours with their FIPG RTVs. The funny part is the Toyota black 103 FIPG has a somewhat thinner body than Permatex gray, tools easier but cures quicker and harder. Permatex states for Ultra/Optimum to wait 24 hours before placing back in service.
Permatex consumer RTVs except for Right Stuff 1 minute want the person applying it to snug bolts by hand, then torque to spec after 1 hour. Right Stuff 90 minute grey is the only one I’ll mess with. Optimum/Ultra Grey takes forever to cure, more than 24 hours.
Curing time depends on humidity.
You can slurp it out with a mity-vac.
I mopped it out with rags and cleaned with brake cleaner.
I once had a diff cover leak when I filled shortly after assembly-- I don't remember exactly how much time passed. So now I'm paranoid and let them sit overnight.
Best is to plan ahead and order a LubeLocker for the job.
And yeah, "pros" use The Right Stuff. I'm usually too cheap to pay for it for my own uses, but in the face of a job for a customer it's negligible.
I also never do a final torque. I let the cheap black skim over in the air, assemble, torque and wait overnight. I've not had a problem personally with THAT. Not recommending, just relaying my experience.
The budget Right Stuff is 90 minute and not that much more expensive than Ultra Black. I prefer that if available (a lot of WM's carry it)
Best is to plan ahead and order a LubeLocker for the job.
And yeah, "pros" use The Right Stuff. I'm usually too cheap to pay for it for my own uses, but in the face of a job for a customer it's negligible.
I also never do a final torque. I let the cheap black skim over in the air, assemble, torque and wait overnight. I've not had a problem personally with THAT. Not recommending, just relaying my experience.
The budget Right Stuff is 90 minute and not that much more expensive than Ultra Black. I prefer that if available (a lot of WM's carry it)
My guess would be that the average auto tech who treats his job as a job rather than a passion like a DIYer would...is not going to pay that much attention into little details like this, nor take the time to fully read instructions. Experienced and master technicians, you would assume know better...but those guys can also be stubborn in that if they've done things a certain way in their career...they'll stick with doing it that way.
Another example would be the use of RTV and gaskets at the same time. All gasket manufacturers will tell you that the gasket should be installed dry only, no RTV unless in areas specified. But watching the various Youtube mechanics, you'll see they commonly slather RTV ontop of a gasket. How much difference does this all make over time who knows. But the reality is even when they take shortcuts like this, chances are the seal will hold up during the warranty period which is all that these guys really care about. Not 10-20 years down the road.
When you start doing your own DIY work, you'll slowly realize that this applies to many other areas of auto work as well and understand there's different ways to do things. The 100% OCD by the book way for maximum reliability, and the short cut methods that might get you 80% of the reliability but at 20% the time. Guess which methods the auto techs who get paid by the job rather than an hourly basis, are going to choose?
For me, I personally stick with gaskets where possible. Especially in areas where you may want to service it in the future (eg. transmission pans, differential covers, valve covers). RTV I leave for areas that are intended to be more permanent.
Another example would be the use of RTV and gaskets at the same time. All gasket manufacturers will tell you that the gasket should be installed dry only, no RTV unless in areas specified. But watching the various Youtube mechanics, you'll see they commonly slather RTV ontop of a gasket. How much difference does this all make over time who knows. But the reality is even when they take shortcuts like this, chances are the seal will hold up during the warranty period which is all that these guys really care about. Not 10-20 years down the road.
When you start doing your own DIY work, you'll slowly realize that this applies to many other areas of auto work as well and understand there's different ways to do things. The 100% OCD by the book way for maximum reliability, and the short cut methods that might get you 80% of the reliability but at 20% the time. Guess which methods the auto techs who get paid by the job rather than an hourly basis, are going to choose?
For me, I personally stick with gaskets where possible. Especially in areas where you may want to service it in the future (eg. transmission pans, differential covers, valve covers). RTV I leave for areas that are intended to be more permanent.
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