Vacuum to remove air from HS2

[aka anglinarcher]

OK, just another update.

In the past, during the summer with new HS2, I have had good results at removing mixed air from HS2 by using my food saver with the vacuum canister. In fact, it was really good.

But, no so much during the winter and with older HS2.

I turn my heat down to 55 in the winter in my man cave. This thickens up the HS2 a bit. During the summer my man cave runs about 85 degrees, and that tends to thin the HS2 down a bit, and speed up the final cure.

I know that some will have read my past post about using the food saver, so I wanted the final update clear. The food saver helped, but it did not remove even half of the air.

[Mike - Alumilite]

Thanks for the post. The food saver trick was new to me as I don't own one and have never tried it. Typically we tell people you want to be able to get down to 29" of Hg of vacuum to effectively degas. Tell me this, when you use the food saver does the silicone rise and then collapse in your mixing container or does it just bring bubbles up and pop them?

You are absolutely correct about the correlation between temperature and viscosity of High Strength 2. I was not aware of the effect it would have on degassing using a food saver.

Thanks for the post and follow up.
Mike

[aka anglinarcher]

The food saver would make the HS2 rise like yeast bread, the bubbles would rise and pop over a 10 minute period.

I have watched your video and it is much better then my food saver. LOL

[Marliner]

What is a good model of vacuum pump that can get down to -30 inches of Hg?
I tried a vane pump but in only got down to -10, which was not enough.
I was thinking of a california tools VP50

[Mike - Alumilite]

We recommend a minimum of a 5 or 6 cfm vacuum pump. Even if the pump says it will pull 29 or 30 Hg, it may take it two days depending on the size of your vacuum chamber which is very misleading. You really need it to get to 28-29" of Hg after 1 minute. Then you will see the silicone rubber really start to boil quickly and remove the air.

Mike

[Fomen38]

I tried using my food saver to degas silicon and casting resin. I put it into the food saver canister just like you did. I couldn't get mine to pull the bubbles to the top. I know my food saver is good because it use it frequently to vacuum save meats and it does a fabulous job. I have noticed that the neoprene gaskets that encompas the vacuum chamber need to be replaced periodically. Lots of guys throw out their food saver bacause they think the pump goes when in fact the only problem is their neoprene gasket has deteriorated and it isn't making an ideal seal anymore. It's also important to note that the gaskets need the be good when utilizing the canister function as well. Although the 1 way ball valve for using the canister is on the top of the food saver, it is funneled through from the vacuum chamber where you place the open end of the bags. I've thought about making a silicon gasket just to see how that would stack up to the neoprene one. I would make it from HS3 because of it's high tear strength and flexibility. Perhaps I will do that and report back. That would be more of a permanent solution to the neoprene issue. I also think by doing this you could potentially get much more vacuuming power from that machine. Although small, it has a decent vacuum pump in it. Not sure how many cfm it is, but it is sufficient to do what it was designed to do. After I replace the neoprene with a silicone gasket, I should try degassing something again. I'm probably losing pressure now because of the degraded gasket.