Red or white RTV on baffling?

[ao.frog]

Hi.

We've just sealed all the openings etc on the baffling and by mistake we used white (clear) RTV.

I'm wondering if we schould replace the clear RTV with red (high temp) RTV?

Maybe the clear RTV in the baffle seals could remain, but what about the RTV which are along the engine case?
It says on the RTV tube that it's ok up to 170* Ceclius (don't remember the F-grade), but 170 seems very little when it comes to along the engine case for example?

[AlexPeterson]

I'm coming up on 1000 hours with clear RTV on the baffles, no sign of any problems with it. If you look up the specs, the orange or red high temp stuff is typically only a bit higher rated than normal RTV. Dig around on the web, you'll find typical specs for both.

[Greg Arehart]

400F = 205C
170C = 340F

greg

[az_gila]

Originally Posted by Mel

The RTV on the baffles should be rated at 400*F.

The black stuff is rated to 400F (and the other non-hi temp stuff)...

http://www.gasketinc.com/afterMarket...x?prodLine=222

Hi-temp RTV is either 500F or 600F and is usually red... but not always.... this Permatex one is black

http://www.gasketinc.com/afterMarket...x?prodLine=225

...any good quality RTV should work on the baffles... and don't forget to seal the gaps at the top and bottom of the oil cooler where it is attached to the rear baffle...

Buy a good quality RTV at your local auto parts store.... those should meet the 200C number...

Do they sell Permatex products where you are?

gil A

[ao.frog]

Hi.

Thanks for the inputs.

The clear RTV I've used is bought from Spruce, part # 09-27800.
It's marked: "Resistant to weathering, -85 to 350F, (-65 to 177C)"

The red one is Loctite 5399 and it says on the label that it's for temps -60 to 275C, max 350C.

So I guess I can start out with the clear RTV and see if it holds up?

Re Permatex: I don't know if I can get that here in Norway, but I'll check it out for sure.
And yes; we've remembered to seal off by the oil cooler. There where quite a few openings there! :-)

[gmcjetpilot]

Originally Posted by ao.frog

Hi. We've just sealed all the openings etc on the baffling and by mistake we used white (clear) RTV.

I'm wondering if we should replace the clear RTV with red (high temp) RTV?

It will take care of its self, it will be gone in 5 hours of flying. The red high temp Permitex®, is like to engine baffle sealing, as rivet's are to aluminum or duct-tape to home repair, they go together. Wear cloves and watch your clothes, it sticks to everything and stays like pro-seal. Just make sure the surfaces are clean with some solvent. If you scuff it, it really will grab on.

[Captain Avgas]

Originally Posted by gmcjetpilot

The red high temp Permitex?, is like to engine baffle sealing, as rivet's are to aluminum or duct-tape to home repair, they go together.

It is my understanding that in the Permatex range the newer Ultra Copper RTV is in fact significantly superior to the Red RTV. It's more expensive (always the way) but it's completely compatible with aluminium and it can operate at higher temperatures than the Red product (up to 700 degrees F). It's also very oil resistant. For baffles and particularly for general FWF requirements this may be the way to go. Check here for further info:

[az_gila]

Originally Posted by Captain Avgas

It is my understanding that in the Permatex range the newer Ultra Copper RTV is in fact significantly superior to the Red RTV. It's more expensive (always the way) but it's completely compatible with aluminium and it can operate at higher temperatures than the Red product (up to 700 degrees F). It's also very oil resistant. For baffles and particularly for general FWF requirements this may be the way to go. Check here for further info:

Yeah.... but Lycoming has a max. temp on your cylinders at 500F, and most folks use a 450F personal maximum. The rest of your Lycoming is oil cooled and should be at a significantly lower temperature.

You shouldn't be able to get any part of your baffles too hot for the red RTV stuff to not work...

gil A

[gmcjetpilot]

Get the good stuff, comes in shinny tube.

http://www.permatex.com/products/Aut...sket_Maker.htm

The latter is all I have used.

[Captain Avgas]

Originally Posted by az_gila

Yeah.... but Lycoming has a max. temp on your cylinders at 500F, and most folks use a 450F personal maximum. The rest of your Lycoming is oil cooled and should be at a significantly lower temperature.

You shouldn't be able to get any part of your baffles too hot for the red RTV stuff to not work...

gil A

Gil I understand what you are saying. But the truth of the matter is that many builders tend to use the RTV not just on the baffles....they tend to use the same product everywhere...including sealing the firewall transitions. In reality they would probably be better off using a proper 2000 degree F firewall sealant on the firewall but the RTV proves to be convenient to use in small applications. On that basis I recommended the Copper over the Red because on the firewall any increase in temperature resistance is an advantage...and the price difference is stuff-all.

And George.....Red is Red, and Copper is Copper (unless of course one is colour blind resulting from activities that we were warned could be detrimental to the eyesight).