heater core gaskets - dress them?

[timspider]

I've gone through pretty much every thread on the heater core and found it to be invaluable. I'm just about ready to re-install everything and wanted to know what folks use to dress the little rubber gaskets, if anything. I have blue RTV silicone gasket maker/dressing and this seems like it would be a good thing to put on these.
Good idea or no?
thanks folks!

[81SPIDERMATT]

rtv or not to rtv is a question that will bring about 2 answers ... yes and no .... on the farm as a boy we used vasoline on the rubber gaskets ... rtv can be used in place of a gasket ... rubber is a good type of gasket material as it gives and will squish somewhat helping to seal .... probably the most important thing is the sealing surfaces are clean and smooth and flat .... with all that being said ... here is what I do and use .... a product called hylomar if you can get it or permatex perma-sheild..there are other types ... what you are looking for is a gasket dressing ..as apposed to a gasket maker . it is more forgiving if you have to take it apart any time in the future ( you wont need a crowbar to get things apart and makes a great seal).. gets applied 4 times ... little dabs on your finger and with good finger pressure I apply a thin even coat to surface 1 ....then to side of gasket mating up to surface 1 ... wait 15 20 minutes and push gasket to surface 1 .... apply again with good finger pressure to other side of gasket and to surface 2 wait 15 20 minutes and screw together to finger tight ... I then let all that sit till next day when everything gets torqued to spec.... I have used this method for quite some time with good results.... good finger pressure and very thin even coats are the key.... in cases where I worry that gasket dressing may get squeezed out and possibly clog something I use anerobic sealer with prep spray .... it only dries where there is no air and the rest of it dissolves in oil or water .... as stated this question will begin a debate more times than not ... only speaking on how I do it .... Matt

edit ... if you go with the anerobic do not wait to tighten everything .. tighten it down as soon as you put it together

[wizard124]

I've gone through pretty much every thread on the heater core and found it to be invaluable. I'm just about ready to re-install everything and wanted to know what folks use to dress the little rubber gaskets, if anything. I have blue RTV silicone gasket maker/dressing and this seems like it would be a good thing to put on these.
Good idea or no?
thanks folks!

I used sealer. No problems.

[majicwrench]

Most everyone uses way toooo much sealer. On a rubber seal, I would not use anything. Silicone (everyones favorite ) is slippery, and weaker than the rubber, or any other gasket. So any gaps it is taking up, preventing the rubber from forming into, are weak spots. It was designed to seal w/o sealer, and it will.
Keith

[timspider]

ok, thanks guys. hmmmm. now not sure how to proceed. I initially felt like the gaskets might do better on their own, which is why I asked the question. Now I'm wondering if the dress would actually keep some rubber from getting into a tiny nook or cranny or if it assists by filling those spots that the rubber would not get into to.
I sure would hate to dress these with something that actually made the seal worse.
Luckily, I have the console out getting any rusty parts buffed up, with wiring to figure out and new carpet on the way, so I can let this percolate for a bit.
thanks for invaluable insights.
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