Lowest curing temperature for Permatex Ultra Grey

[Jean-Sebastien Stoezel]

Hi:

We're having an exceptionally cold and long winter up here in Winnipeg, Canada. I have an insulated garage, but I just heat it when I'm working in it (don't trust the electric heater). I don't want to leave the heat overnight and can't guarantee the temperatures will stay higher than 0C overnight.

I've been putting off to reassemble a transmission due to the low temperatures (and low ambient humidity) which seem to delay the curing of Permatex Ultra Grey.
Looking at the forecast it seems I won't be getting positive temperatures for another week... So I need to get going.

Looking at the technical datasheet, there's no specification on lowest curing temperature. It just specifies that "Longer cure times will apply to applications in low humidity conditions or colder temperatures."
The environmental resistance is specified to as low as -54C but there's no specific minimum curing temperature.

Has anybody experienced bad curing due to low temperatures? If so, how low was it?

Thanks,
Jean

[Albatross]

Why not call Permatex in Conn. Toll free 877-376 2839; or their local: 860-543-7500

[DaveW]

"TYPICAL CURING PERFORMANCE
Permatex Ultra Gray Gasket Maker cures on exposure to moisture in the air. The product dries tack free in one hour and fully cures in 24 hours. Cure times will vary with temperature, humidity and gap. Longer cure times will apply to applications in low humidity conditions or colder temperatures."

I'd guess, since it cures using water from the air, that trying to cure it below freezing would not work very well.

[Hardingfv32]

You do not need sealer if you are using gaskets. I do not even replace them during rebuilds if they are not damaged.

Brian

[Rick Kirchner]

what about putting a hot plate with a pan of water under the gearbox? Let it boil, the steam will heat the box and generate the required local humidity.

[autodoctor911]

I would expect that it will need at least an hour at temperatures above freezing, and it will be good enough to fill with fluid from my experience. I wouldn't put any more pressure than that on it for a while though. I have had ultra grey that was not fully cured displace under cooling system pressure, or manifold vacuum, but not just from the force of gravity on a contained fluid.

That said, though, I prefer to use anaerobic instead of ultra grey any time the surfaces are stiff and flat(machined castings or thick plate). It is strong enough for anything almost immediately, regardless of temperature, and lasts longer, as well as being easier to use. It is a little more expensive, but well worth it in my opinion. The only time I use the Ultra Grey is for plastic, or sheet metal pieces, or irregular surfaces(pitting, scratches, etc.). You can also take your time putting it together when it's hot and humid, where as the silicone is already skinning up as soon as you squeeze it out.

[Jerry B.]

Slow or no curing of the Grey might be because of out of date product. I find that fresh dates (nine months) or nearer performs, where as over a year or more it might not cure especially if it is put on thick between parts.

Look at the bottom of the tube where the crimp serrations are.......
first numeral is year ....1 would be 2011 2 would be 2012 and so on
next digit is a letter and it denotes A = January....B = Feb and so on.

I have seen in some parts stores up to two years old product.....same deal with
brake fluid. Unlike most foods that have to be clearly date marked, stuff we use
has no or convoluted secret date codes.

[Modo]

I use a light near stuff to keep warm or to warm up area, far enough away so oil doesn't catch, trouble light under gearbox should work

[BillH]

Why even bother with Permatex RTV?

Switch to Permatex The Right Stuff and you'll never go back to RTV.

I threw out all my RTV 10 years ago after using TRS the first time,

If you have to change gears or pull the rear cover at the track, you don't have the time to wait for RTV to cure, If you use TRS, you can drive the car immediately (with no leaks).

[Jerry Kehoe]

I have used Hylomar for over40 years, always works great,easy to clean off. Beware of the phony private label stuff though. You can get Hylomar at Grainger for about 12-15 dollars a tube. Just lightly brush on both surfaces and assemble. Gearlube doesn't affect it nor cold or hot weather.

[ReynardF1000]

Maybe not possible, but, take the widget in the house for this step?!

[R. Pare]

Your problem "cure' is simple - put the gearbox under a blanket, or in a large box, and direct a small electric heater into the enclosure. Voila - you've made a curing "oven".

[Steve Demeter]

Our Forum sponsor Keith Averill sells Hylomar.

I have used Hylomar for over40 years, always works great,easy to clean off. Beware of the phony private label stuff though. You can get Hylomar at Grainger for about 12-15 dollars a tube. Just lightly brush on both surfaces and assemble. Gearlube doesn't affect it nor cold or hot weather.