When to, or not to, use rtv silicone?

Holly · Post by **Holly** » Fri Jul 22, 05 2:31 pm

OK, I know this stuff is waterproof, but would it be ok to use on a leaky thermostat housing? (with a gasket as well) Or would the water pressure Bananarama! out?

Anonymous · Post by **Anonymous** » Fri Jul 22, 05 2:41 pm

James i have got instant gasket on mine and its ok

Holly · Post by **Holly** » Fri Jul 22, 05 2:46 pm

I put instant gasket on it last time, but I've lost the tube ... got lots of silicone though, lol

TrevD · Post by **TrevD** » Fri Jul 22, 05 2:52 pm

james , most silicon sealer will work but some bathroom sealers cant handle the heat for long ( ok to get you out of trouble)if it sais RTV silicon it will be ok

Alex · Post by **Alex** » Fri Jul 22, 05 3:08 pm

I agree

Anonymous · Post by **Anonymous** » Fri Jul 22, 05 4:03 pm

The two best ever silicon sealers are, and in no order

Cummins do one for specifically sealing the top land on their cylinder liners, excellent stuff as the liners do fret a little but the sealer works and keeps the water in for a very long time/high mileage, soul destroying job though when they do leak as it's all the liners out for 1/6th bead of silicon, not found anything else that will do that job and last, available from all Cummins diesel dealers.

Cat silicon, 2 or 3 different ones depending on the app but all excellent, will also seal top liner lands. Available from all Caterpillar dealers.

No silicon will work if the man on the wrench gorilas the bolts/nuts while it's still wet, will just squidge the stuff and the gasket right out.

If there's a Cummins or a Cat dealer close by don't mess about with the rubbish from halfords go get the real stuff

Holly · Post by **Holly** » Fri Jul 22, 05 4:14 pm

ok, thanks guys

I have a big tube of RTV that I got for the rocker cover gasket (they were done with it from the factory), so that saved me a trip to the shops for another thing I'll only use once in a blue moon

Neil - I got this stuff from a heavy engineering supplies place, so I think it'll be ok!

Anonymous · Post by **Anonymous** » Fri Jul 22, 05 4:52 pm

hey James i'm sure it will, I was just passing on the two best in my opinion, end of the day a thermostat housing isn't that taxing for silicon but liner lands are

both are american companies and industry leaders and another thing i've noticed neither of them have that acetic acid / chip shop vinegar stink like normal silicon, which makes me want chips everytime I use the stuff

Holly · Post by **Holly** » Fri Jul 22, 05 10:42 pm

This stuff I've got doesn't really smell of anything

Anonymous · Post by **Anonymous** » Sat Jul 23, 05 10:29 am

Most of the good stuff doesn't, a light smear is all you should need if everything is flat and just tighten the bolts a little until it's gone off then tighten to correct torque afterwards.

With silicon while it's still wet the gorilla approach isn't the best way as that will just split the gasket

Holly · Post by **Holly** » Sat Jul 23, 05 1:10 pm

The thermostat housing appears to be twisted (!) so it ends up with a 1mm gap on both sides (in different places) - I do have a gasket, so I've put a bead on both sides and tightenned it all up ... guess I'll find out if it works later today!

Alex · Post by **Alex** » Sat Jul 23, 05 1:58 pm

James the housing twisting is common, I sually file them flat(er) then fit them up!