silicone grey gasket maker question
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
silicone grey gasket maker question
using for the thermostat housing and wonder if I have to let cure for 24 hours to be effective of just wait couple hours and snug up bolts and go, you thoughts or experience 
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Wouldnt let it cure before torquing down, maybe just long enough to start "skinning over" if anything thats it. Just let it cure before running the car, if thermostat gasket seems to last better waiting for cure before adding coolant.
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
thanks, not using the right stuff as I didn't know about it but will buy some for the toolbox tomorrow and use if the grey stuff doesn't work, worked last time but it sat for 2 days before I drove it, can't do that this time
Drifting
Joined: Dec 2009
Posts: 1,349
Likes: 34
From: Porterville Ca
The grey stuff usually works best on machined surfaces like newer cars with machined aluminum oil pans/valve covers to blocks, use the "right stuff", works great filling gaps like intake manifold corners etc,
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
any regular rtv even the right stuff is not compatible with cooling systems with antifreeze, although the right stuff will last longer than the regular, it will still leak over time with antifreeze....
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Silicone sealant (except 'real' RTV) won't seal properly. Use 100 grit sandpaper to scuff and flatten the sealing surfaces [especially if you are using any chromed components], clean well with a volatile cleaner, use fiber or composition gasket with light wipe of Permatex gasket sealer on both gasket surfaces and assemble using proper bolt torque. Also, put some of the Permatex gasket sealant on the lower threads of those bolts so that any coolant will not 'weep' up the threads.
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Permatex, makes primarily two different catagories, gasket makers and gasket sealers (for use with gaskets).
If using with a gasket you can fill right away, if using a gasket maker, wait overnite if possible. Never had problems either way.
All the Permatex RTV gasket makers are silicone and several can be used for the housing.
Although a few bucks more and well worth it, the Right Stuff is rubber and by far the best for problem surfaces and can be used within a few minutes. Still cheaper than rework though.
Here are two that are grey that are recommended for tstat housings.
These work well too.
Water Pump Sealer (Stewart Water pumps are shipped with this)
Their top line grey silicone
Here is their main page
http://www.permatex.com/products/Aut..._gasketing.htm
Here is the UltraGrey RTV Silicone
http://www.permatex.com/products/Aut...sket_Maker.htm
Here are their detailed intsructions for it's use. Just click on the "TDS" link on their product page for instructions
http://www.permatex.com/documents/td...tive/22071.pdf
http://www.permatex.com/documents/td...tive/82194.pdf
Look under the Chemical / Solvent Resistance on each TDS for compatability if in doubt.
If using with a gasket you can fill right away, if using a gasket maker, wait overnite if possible. Never had problems either way.
All the Permatex RTV gasket makers are silicone and several can be used for the housing.
Although a few bucks more and well worth it, the Right Stuff is rubber and by far the best for problem surfaces and can be used within a few minutes. Still cheaper than rework though.
Here are two that are grey that are recommended for tstat housings.
These work well too.
Water Pump Sealer (Stewart Water pumps are shipped with this)
Their top line grey silicone
Here is their main page
http://www.permatex.com/products/Aut..._gasketing.htm
Here is the UltraGrey RTV Silicone
http://www.permatex.com/products/Aut...sket_Maker.htm
Here are their detailed intsructions for it's use. Just click on the "TDS" link on their product page for instructions
http://www.permatex.com/documents/td...tive/22071.pdf
http://www.permatex.com/documents/td...tive/82194.pdf
Look under the Chemical / Solvent Resistance on each TDS for compatability if in doubt.
