hylomar blue for petcock diaphragm??

[snowbeard]

so I suspect my petcock gasket of leaking, as there is gas coming thru the vacuum hose :roll:

I have some hylomar blue, and I've only used it once to seal the plug caps when I reseated them, so my question is:

does hylomar blue ever "set up" and dry?

it says it's impervious to engine liquids, but if it's not going to dry it will eventually just get sucked thru into my cylinders...

anyone know definitively? :?

thanks again!!!

[Jethro]

If I'm not mistaken, hylomar is silicone based, and while it may resist oil and anti-freeze, gas may be a solvent to it. Are RTV and hylomar one and the same? I believe they are. Becasuse RTV is silicone based. Not good with gas. It does set up firm- RTV= room temperature vulcanizing.

I expect I have been little to no help. You're welcome very little.

[DaveDanger]

Hylomar Universal Blue has the following properties:

Non hardening and non setting
Unlimited assembly time
Vibration resistant
Allows metal to metal contact
Resistant to combustion products, water, engine coolant, petroleum, lubricating oils, kerosene and fluorocarbon refrigerants
Seals surface imperfections
Withstands rapid variations in temperature
Flame, dust and moisture proofing properties

Hylomar Silicone has the following properties:

GASKETING
HYLOMAR RTV silicone sealants can be used to produce FIP (Form In Place) gaskets either by robotic equipment, cartridge gun or direct from a syringe. Use Hylomar RTV silicone products to produce high quality gasketing solutions, improve sealing performance over conventional gaskets and reduce costs.

SEALING
HYLOMAR silicone sealant remains flexible when fully cured and has large gap filling capabilities. The excellent dielectric properties, which are retained over a wide temperature range, make silicone sealants ideal for sealing industrial and domestic equipment.

Typical applications include: electronic components, industrial safety switches, electrical appliances, pipe connections and air conditioning units.

BONDING
The high strength nature of silicone sealants makes them ideal for bonding. It is particularly suitable for applications where large gap filling and high temperature is required.

See individual technical data sheets to choose the most appropriate product for you or contact us for technical support and advice.

[Guy]

Hylomar blue is fine to use on all surfaces, with or without gaskets, and it's not dissolved by petrol. If you have fuel leaking down the vacuum line, it's more likely the diaphram's split, and the only cure is to replace it.

[snowbeard]

yep, took it apart and somehow the frame that surrounds the stopper and holds out the diaphram was in four pieces, busted at all of the four narrow spots! don't know how that happened, but it's poked a hole in the gasket now. have to figure out the rest of the issues before I get any further...

here's my current dilema...

http://www.thegsresources.com/_forum/viewtopic.php?t=42890