Silicone gasket trick

Here is another way to make high temp silicone gaskets. I used a piece of 1/4" ID tubing (3/8" OD) and a brand new tube of high temp silicone to make a nice rope gasket .

Just trim the end of the applicator, insert the end into the tubing and secure the connection with tape so that the pressure will not cause a blowout. (I used really sticky aluminum tape, but duct tape would probably work too). Now squirt the tubing as full as you can. It takes a lot of squeezing to push the bead of silicone all the way through the tube - I literally had to stand on the tube to get the length that I needed. Finally, open both ends of the tube so that the silicone can dry. I left it outside in the sun for a couple of weeks.

After drying, I took a utility knife and adjusted the blade and carefully made a split all the length of the tubing, being careful not to cut much into the gasket. Than pull out the silicone rope and there you have it. A perfectly formed 1/4" round high temperature silicone gasket.

Gary,That’s a good method and good results. I had thought to find a small channel, grease it and fill it with silicone. Then cut the gasket to length and glue the ends together with silicone.

Now why didnt I think of that!!!

Pretty cool Ill be giving that a try :slight_smile:

Nifty! I wonder if some anaerobic sealant would cure faster and still be high temp?

I liked your idea so much I decided to make one today. I found that if you use a pipe (rolling pin, etc.) I could squeeze some into the tube, then use the pipe to “run” the silicone to the end. Sqeeze more from the tube, roll the next batch until it joined with the first, and so on. It took the full tube of sealant, and is now curing in the hot (100 degrees) sun. Thanks for the great idea.

Thank you for the idea of working the sealant through the tubing mold with the rolling pin action.
I am not sure if the sun or the heat does anything for the curing - it may just need air and time.

yeah I looked it up and it does not use a UV curring process its an evaporative process.

Mmm, just thinking, they sell two part silicone for mold making. Cures by catalytic action. Some of it they say you can actually cast low melting metals like pewter in it. I guess that would make a good gasket, and wouldn’t have to wait for days to cure.

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