PTS Flowbench Forum

BUILDING A PTS BENCH FROM THE PLANS. AFTER STUDING THE PLANS I DECIDED TO BUILD THE LEFT SIDE OF THE BENCH WITH THE UPPER AND LOWER CHAMBERS FIRST TEMPERORLARY LEAVING OUT THE BLOWER MOTOR BOARD AND THE SLIDER SELECTOR UNTIL AFTER TESTING FOR LEAKS. NO HOLE WAS CUT IN THE TOP YET, NORE IN THE CENTER PANEL. VACUME WAS APPLYED TO ONE OF THE TEST PORTS OTHER TWO WERE PLUGED USING A VACUME PUMP AND A REGULATOR I SLOWLY APPLYED VACUME I COULD ONLY GET A MAXIUM OF 5 IN OF VAC ON THE BOX WHEN APPLYING AS MUCH AS 25 IN OF VAC. SO I HAVE A LEAK, THEN I USED AN AUTOMOTIVE SMOKE MACHINE LEAK DECTOR TO PRESSUREISE THE BOX WITH SMOKE, COULD NOT SEE ANY LEAKS, CONFUSED, SO I HOOKED UP A AIR LINE AND REGULATOR AND PRESSERISED THE BOX TO 10 PSI SOAPED DOWN THE ENTIRE BOX TOP TO BOTTOM EVEN HAD IT UP ON BLOCKS TO DO THE BOTTOM CANT FIND ANY LEAK. ANY IDEAS

10PSI ????? ! are you still their???

24"*24"= 576 sq" * 10psi and you have 5760 Lbs of force on each panel if the office hole is Cut you have over 11,000lbs of force on the side panels

Think about what you are doing???

If you are using MDF and haven't painted the MDF board....that is were you are leaking! Still have that picture in my mind, from the old form, and the soapy water bubbling through the MDF Boards.
Any one know how to find that picture?
Really drive it home how necessary it is to paint the inside of your bench.

This one?

Thanks Bruce!
Yup

melamine was used I was told it was not porous, and as I said I soaped it all down

First of welcome to the Forum i know you have been lurking but of course this is your first thread, I would use a different vacuum source such as a shop vac it should pull at least 90" if the box is sealed tight, if the joints are not glued and sealed then it will be less.

As to your other post now that you have clarified that you are using melamine you do have to be very careful as the what pressure you use as melamine has less dense structure than MDF and in my opinion is a weaker material.

I think your box is sealed if you can hold 10PSI as you say, it is most likely your vacuum source.

Rick

Wow 10 psi. That's near 300". Don't do that again man.

Jim