[68NovaSS]

Originally Posted by AutoGear

If its a pain to install your new headers, I would call Sanderson and ask.

Nah, it's not a pain, just noting what they say in their tech sheets.

[Mr. P-Body]

There is no weather stripping in an engine. The use of it as a gasket sealer is NOT recommended. I used to see people use it a LOT to hold valve cover gaskets to the covers in "solid lifter" engines for adjusting. I've also seen innumerable valve covers destroyed trying to get that stuff off them. After you've had to clean up after this, you won't be so apt to recommend it.

FWIW

Jim

[hcompton]

No do not use RTV on older engines. It is only used on engines that call for it. My Q45 comes to mind it had a front timing chain cover with no gasket and required high temp orange/copper rtv to seal it up.

For valve cover gaskets rtv will make them leak do not use. Use either nothing for rubber gaskets or Indian Head gasket sealer for cork and paper gaskets. That is made for cork gaskets rtv is not.

Basicly toss the stuff in the trash and use what the manufacturer recommends. Never use rtv for anything that does not call for rtv in the shop manual. If you have a older chevy you dont need it at all.

I am stunned with all the back and forth and not one of them said to check the manual for the proper sealent. If you use rtv on paper or cork it will leak for sure. Maybe not today but by next year you will need new gaskets when they should have lasted the life of the car.

This is the magic juice. It works like crazy and forms a glue that will hold your gaskets in place while you install the part. just a lthin coat on each side of the gasket and it will tack up in a few minutes holding your gaskets in place as you turn the part over to install it. Helps a lot with heavy intakes and other parts that require fiddling that can move the gasket out of place.

Permatex 20539 Indian Head Gasket Shellac Compound, 2 oz. : Amazon.com : Automotive

Permatex 20539 Indian Head Gasket Shellac Compound, 2 oz. : Amazon.com : Automotive

RTM!!!!

[68NovaSS]

Originally Posted by Mr. P-Body

There is no weather stripping in an engine. The use of it as a gasket sealer is NOT recommended. I used to see people use it a LOT to hold valve cover gaskets to the covers in "solid lifter" engines for adjusting. I've also seen innumerable valve covers destroyed trying to get that stuff off them. After you've had to clean up after this, you won't be so apt to recommend it.

FWIW

Jim

Read my posts, I'm not recommending anything to anybody, the manufacturer is, I'm just showing what their recommendation is.

FWIW

[1971BB427]

I use Ultra Black RTV always on SBC and BBC intake gaskets to replace the front/rear gaskets that I toss. Also use it on pan gaskets, timing cover gaskets, rearend cover, or thrid member. I never use it on transmission pan gaskets unless the gasket is not the self sealing type. Tried it with the black self sealing gaskets and it leaked like a sieve. Those type trans pan gaskets are made to react to trans fluid, and they wont work if you have RTV on them.

[gearheadslife]

g.m used rtv allot,,
find me a 2.5ltr iron duke pan gasket/timing cover/etc.. there was none, not even when new, felpro made some and sometimes you can find them.. but g.m. shop manual calls for rtv.. no gaskets..
the glue, makes it a p.i.t.a. to remove, but leaks are non issue 99% of the time..
form-a-gasket is heaven, as long as your not doing the next r&r

[oldbogie]

Originally Posted by Mr. P-Body

A couple "rules of thumb":

RTV is only used in the corners where pans/blocks/heads/manifolds "come together". Some engine families need the pan lips "beaded". NEVER on the pan "rails".

Two machined surfaces and a paper gasket, DRY, is the MOST effective way to seal.

If a little is enough, A LITTLE IS ENOUGH! A "lot" is NOT better.

Permatex "Ultra Black" is the only type (RTV) we use on internal engine parts. Not a "high temperature" sealant, I would avoid it on the headers. The red "High Temp" RTV is more desirable there.

Permatex "Aviation" is a brush-on sealant used around water outlets in heads, oil pump flanges, and other areas where minimum "thickness" of the glue is desired. It is also the sealant "of choice" for head bolts that go into water (Chevy, big Dodge, some Fords). Similar products you may be familiar with are "Indian Head", "Kopper Kote" (brush on) and Permatex "Super 300". "Aviation" is FAA-approved for use in internal combustion engines.

"The Right Stuff" (also a Permatex product) is quite popular these days. I don't like it, as it's too hard to "work" with.

Far-and-away the most problems we see with DIY builds, is too much sealant used. Sheet metal parts get damaged trying to get them off. Oil pumps die a horrible death when globs of RTV get sucked in. I've even seen a Rambler V8 with the oil passage from the pump to the block almost completely blocked, where no sealant AT ALL was needed.

We "glue" model cars together. Real ones use bolts... (:-

Jim

Pretty much X2 with Mr. P-Body. I'll add one place I never use RTV is a sealer for bolts that penetrate in to wet or oily places. My preference for the likes of Chevy head bolts and same/similar situations in other auto/machine brands is Teflon Plumbers Sealant.

P-Body where did you get " We "glue" model cars together. Real ones use bolts..." priceless!

Bogie

[gearheadslife]

Originally Posted by Mr. P-Body

We "glue" model cars together. Real ones use bolts... (:-

Jim

big boy glue is called spot welds..

[BigEsGarage]

Originally Posted by hcompton

No do not use RTV on older engines. It is only used on engines that call for it. My Q45 comes to mind it had a front timing chain cover with no gasket and required high temp orange/copper rtv to seal it up.

For valve cover gaskets rtv will make them leak do not use. Use either nothing for rubber gaskets or Indian Head gasket sealer for cork and paper gaskets. That is made for cork gaskets rtv is not.

Basicly toss the stuff in the trash and use what the manufacturer recommends. Never use rtv for anything that does not call for rtv in the shop manual. If you have a older chevy you dont need it at all.

I am stunned with all the back and forth and not one of them said to check the manual for the proper sealent. If you use rtv on paper or cork it will leak for sure. Maybe not today but by next year you will need new gaskets when they should have lasted the life of the car.

This is the magic juice. It works like crazy and forms a glue that will hold your gaskets in place while you install the part. just a lthin coat on each side of the gasket and it will tack up in a few minutes holding your gaskets in place as you turn the part over to install it. Helps a lot with heavy intakes and other parts that require fiddling that can move the gasket out of place.

Permatex 20539 Indian Head Gasket Shellac Compound, 2 oz. : Amazon.com : Automotive


RTM!!!!

I don't know man.... I've been using RTV for years on paper and never have had a problem, or I wouldn't use it.
I really think most over do it and that's why they have problems.

[cobalt327]

Another problem besides using too much is not allowing it to skin over per the instructions before installation. RTV in an uncured state is a lubricant; some gaskets can be squeezed right out from between the joint.

No harm in using it on paper. The taller and thinner the gasket w/long runs between fasteners, the less likely for a good result because of the chance of displacing the gasket from the joint that's being sealed- like a cork valve cover gasket. On a flat, wide surface- like a water neck gasket or a fuel pump gasket (paper, both) they will seal fine w/RTV should you choose to use it.

New/freshly machined gasketed flat surfaces are less likely to need any sealer- RTV or otherwise- unless the application or common sense dictates otherwise. Old, corroded, scratched and/or uneven surfaces can often benefit from using a sealant, RTV is among those that can work well.

I would never use RTV on a threaded fastener like head bolts. Permatex Aviation or #2 works well for me, other people prefer teflon sealers which also work fine.

BTW, most of us who've been doing this for a while understand what is meant when the word "Permatex" is used. Before there were OTC RTV sealers, Permatex (#1, #2, #3 and in cans) was one of the standards, along w/Indian Head and K&W Copper Coat.

[T-bucket23]

Originally Posted by Mr. P-Body

There is no weather stripping in an engine. The use of it as a gasket sealer is NOT recommended. I used to see people use it a LOT to hold valve cover gaskets to the covers in "solid lifter" engines for adjusting. I've also seen innumerable valve covers destroyed trying to get that stuff off them. After you've had to clean up after this, you won't be so apt to recommend it.

FWIW

Jim

Never had an issue as it never really hardens and peals right off . Only been using it for 35 years without issue

[cobalt327]

Originally Posted by T-bucket23

Never had an issue as it never really hardens and peals right off . Only been using it for 35 years without issue

I believe the 'High Tack'-type gasket spray and brush-on, including Copper Coat, etc. are basically weather strip adhesive or rubber cement.

I use 3M weather strip adhesive to hold valve cover gaskets in place (valve cover side only), same thing for non silicone oil pan gaskets, trans pan gaskets, diff cover gaskets, etc. Just a few dots or a light spray if using aerosol, not using it as a sealer per se. Just as an assembly aid, like a third hand so to speak.

[T-bucket23]

Originally Posted by cobalt327

I believe the 'High Tack'-type gasket spray and brush-on, including Copper Coat, etc. are basically weather strip adhesive or rubber cement.

I use 3M weather strip adhesive to hold valve cover gaskets in place (valve cover side only), same thing for non silicone oil pan gaskets, trans pan gaskets, diff cover gaskets, etc. Just a few dots or a light spray if using aerosol, not using it as a sealer per se. Just as an assembly aid, like a third hand so to speak.

Exactly my point

[sbchevfreak]

Originally Posted by cobalt327

I believe the 'High Tack'-type gasket spray and brush-on, including Copper Coat, etc. are basically weather strip adhesive or rubber cement.

I use 3M weather strip adhesive to hold valve cover gaskets in place (valve cover side only), same thing for non silicone oil pan gaskets, trans pan gaskets, diff cover gaskets, etc. Just a few dots or a light spray if using aerosol, not using it as a sealer per se. Just as an assembly aid, like a third hand so to speak.

I've done it like this for years. Can save a major PITA if the part goes into a difficult to access area. (read, newer vehicles)

Still have a few cans of Permatex 1 & 2 in my tool box..... Right beside my valve lapping compound