I was reverse turning the bottoms on some bowls on the vacum chuck and had a small thin one on at apparently too high of a vacum so BANG ( and yes it was loud) the center of the bowl shattered. I knew better just not thinking about the pressure and how thin this bowl was. No harm done just hate losing any bowl especially in the last stage.

That does suck. Glad the only thing lost or hurt was the bowl

19 minutes ago, Chips N Dust said:

That does suck

Was that a pun??? 

 

1 minute ago, lew said:

Was that a pun??? 

 

No it wasn't. Didn't even think of that when I replied

32 minutes ago, Chips N Dust said:

That does suck. Glad the only thing lost or hurt was the bowl

Yup, bowls can be replaced! After all, that stuff DOES grow on trees.

John

47 minutes ago, Gerald said:

just hate losing any bowl especially in the last stage.

or any other project...

I did something similar but a whole lot stupider! Been a while ago but I finishing a bottom and noticed I was losing vacuum, and saw I had a little crack in the bottom. No big deal I thought, I'll just put some thin CA in it, when it sets up I'll finish. Put some in the crack and waited, waited, put some more in, waited, waited, put some more in, etc. etc. etc. When it finally dawned on my what was happening  I pulled the bowl off and sure enough, I had CA glue everywhere inside that chuck. Fortunately, I didn't ruin anything except the seal on my chuck had some crusty spots on it. I'm just glad it didn't get sucked up into the venturi and ruin it.

 

Steve

I don't have a vacuum chuck but didn't think there was that much pressure.  Glad you weren't harmed.

With vacum chucks there are several things to remember.

      1. All wood is porous and will leak vacum. The thinner it is the more will leak on woods like red oak.

      2. Thin bowl also flex and will crack or implode with too much pressure.

      3. Pump must have a prefilter and it must be maintained.

      4. Yes dust gets into the vacum line and the chuck.

      5. Take only very light cuts and keep the tailstock up as long as possiblle.

      6. Do not use extremely high speeds.

There is probably more, just cannot think of it now.