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high pressure burst disk glue?

Posted: Sat Feb 16, 2008 5:53 pm
by Sticky_Tape
Hello I am currently back from my trip to the hardware store and I am making a burst disk pnematic and I would like to know is it ok to glue on somthing that exsperiences high pressures? If so what glue should I use jb weld or epoxy? I have both.

Posted: Sat Feb 16, 2008 6:39 pm
by Thursto
well it depends what you are gluing and how much pressure/stess (what is high pressures ?) is it going to take. but im sure JSR would suggest epoxy (because he is the epoxy king around hear :roll: ) But it is a very good strong bonding glue. Just needa know some more details. But more then liekly super strong epoxy will do it.

hope this helps.

Posted: Sat Feb 16, 2008 6:41 pm
by elitesniper
what do you mean glue? you mean the fittings? If its the fittings you use primer and cement. You need more detail of what your saying.

Posted: Sat Feb 16, 2008 6:48 pm
by Sticky_Tape
Sorry I forgot to add that I am glueing copper and brass and the max pressur I would take it to would be 160 psi.

Posted: Sat Feb 16, 2008 6:50 pm
by Thursto
ahk well i think it'd be better to solder it, not glue it, but i think i have hear of people epoxying it, i think they use super strength epoxy putty glue and sand it down after ot dries to make it a nice smooth surface.

Posted: Sat Feb 16, 2008 6:52 pm
by Sticky_Tape
That's what I thought thanks :)

Posted: Sat Feb 16, 2008 6:54 pm
by Thursto
no problems, im not the expert on copper so i wouldnt take my word for it, but i'd wait for some of the other members to reply.

Posted: Sat Feb 16, 2008 8:31 pm
by DYI
If you're using copper and brass, and only 160 psi, epoxy might not be a bad idea.

But I don't quite understand the application, because most brass at hardware stores is threaded, and all copper tube is unthreaded, which means attaching threaded adapters to the copper... which in turn means attaching copper to copper, not copper to brass. If you're using a fitting that's brass and intended to be soldered to copper, I don't know how well Just For Copper epoxy would work, although it is the obvious choice for joining copper when you're too lazy to do soldering.

Posted: Sat Feb 16, 2008 9:22 pm
by Sticky_Tape
The brass fittings I am useing are unthreaded were you would glue the copper to. The fittings I bought were a half inch male adapter and a half inch union. The male adapter screws into a 1 1/4-1/2 inch steel reducer which connects to a 1 1/4 inch nipple that is five inches long that connects to a coupler into another nipple and then a endcap with a tire valve in it.
you are probably wondering why I used steel it was because I didn't have acess to 1 1/4 copper to exspencive no pvc there was unrated abs which is bad and steel was the next cheap thing that won't explode :D

Posted: Sat Feb 16, 2008 9:35 pm
by D_Hall
DYI wrote:which in turn means attaching copper to copper, not copper to brass.
I've seen brass conduit attachments... Which can be pipe thread since they want it to be water proof. Voila, copper to brass.

Posted: Sat Feb 16, 2008 9:52 pm
by Sticky_Tape
I lust J. B. Welded it and it will be ready in 15 hours I'll post a picture when it's done.

Posted: Sat Feb 16, 2008 9:57 pm
by Sticky_Tape
Oh yes and I also calculated the chamber to barrel ratio to be 2:1 the barrel is 3 feet long and each foot holds 50 ml of water half of the chamber volume is 162 ml 50 into 162 equals roughly 3.

Posted: Sat Feb 16, 2008 10:58 pm
by rp181
I epoxied a copper 90 to a brass Tee, as soon as there was a small leak,the whole chamber shot off, this was at <50 PSI.

Posted: Sat Feb 16, 2008 11:17 pm
by DYI
I epoxied a copper 90 to a brass Tee, as soon as there was a small leak,the whole chamber shot off, this was at <50 PSI.
And that is because you didn't do it properly.

@D_Hall: I don't quite know what you mean, are you talking about threaded copper pipe (which I've never heard of)? Because I meant that the socket fitting would be copper tube ---> copper threaded adapter ----> brass threaded pipe/fitting.

Posted: Sun Feb 17, 2008 10:18 am
by Sticky_Tape
It is now 2 hours until the J. B Weld fully dries and this is what it looks like more pics to come.