Creating Seal between copper and Polypropylene
 

What is the best way to make this seal? I don't have any clue about even the basics of sealing, so any help would be appreciated. Polypropylene is just a non-porous cheapo plastic used in tanks and ducts, and i'm using it as the cap ontop of my copper block. I was thinking either some kind of rubber type material around the edge of it or a adhesive/caulk type material??? Can you point me towards any material names or brands that will help me out? Thanks!

Marine Goop.... "Sticks like shiate" :D

cool, thanks. i assume 3.7 ounces is more than enough, right?

O ring and bolts also does fine.

boo

O ring groove in copper and bolts will seal up to 1000psi if you follow the following guideline:

H=2/3*D
W= 1.18*D to 1.2*D

Where D is the cross sectional diameter of the O ring
H is the depth of the groove
W is the width of the groove

The groove can be cut with a standard endmill, no need for a special cutter.

It actually works:

where did you get that 1000psi number? why dont you try putting 1000psi thru your block, I gaurentee its gonna splode.

as for sealing, marinegoop or rtv silicone and screws works insanely good, another thing that works great is JBweld


Jon

I just made and used a liquid cell that had to hold water at STP inside a chamber that was UHV (10^-7 torr or so). Just a groove, an o ring, and 4 hex bolts holding it down. Never leaked in 5 days of experiments...

o-ring and the groove, it works great............

I know this........


HEHEHHEHEHE

The block would explode because the top is made out of acrylic. If the top were made out of copper It would probably hold. I got that number from cathar.

O rings are used to seal much higher gas pressures than 1000. However you shouldnt need to be even close to that number.

Ive used standard rubber, urethane, and teflon o-rings to seal above 1400 psi nitrogen pressures.

so 1000 is a low "baseline"...

Ok, now with that being said, anyone remember the PSI number that the MAZE 2 held before it exploded? And it was a soldered top block.



Come on............ I know some of you guys have to remember.......

If you can't old chap, what hope is there for us?! :p ...

Oh I remember, it was a big deal on there site, They made a point to advertise that the block could take 1000 psi. I beleive that the bursting point was between 1200 and 1400 psi.....

go to dangerden.com click on the 'tested at 1000+psi' text in the logos and whatnots, It should still be there, They have a video, I think it held at 1400psi for a little bit...

Do they use soldering or brasing for sealing the maze2 ?

Yep, somewhere around 1300-1350. I watched that video several times. Though it was a Maze1, the ol´ original.
regards
Mikael S.

I think you all see where I was going with it though...............


that is why I used O-rings from the very beginning.

Hmmm, I've never said 1000PSI for O-rings, I've always said 300+PSI, which is information that I attribute to BillA. I do recall saying about the Loctite 567 thread sealant for barbs which is rated for well over 1000PSI, which is perhaps what's being referred to here.