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JB weld

Posted: Thu Oct 04, 2007 3:48 pm
by mikeac
I have noticed a few people have used JB weld and pvc in the construction of a condenser (not in the vapor path). I tried the same thing but used different glue with crappy results....

Does the JB weld bond well with pvc and copper???

Will using ABS pipe be any different then pvc (I have some lying around)??

Posted: Thu Oct 04, 2007 4:51 pm
by TRANSPLANTED HILLBILLY
JB weld bonds well with just about everything. Its good stuff to have layin around if ya like to work on a little bit of everything. It can be drilled, machined, and even taped with threads if they don't have to be very strong. It's just good stuff. It does take awhile to cure though, the quick stuff isnt as good as the long cure.

Posted: Fri Oct 05, 2007 3:15 am
by Rudi
I got the snots with my pvc outer liebig condensor.

JB weld works best IMHO bonding two things that expand and contract at the same rates when heated and cooled copper and pvc dont.

First run was good but when it cooled it must have cracked the second run leaked.

I coated the whole join with epoxy glue it lasted 5 runs then leaked.Its now in the "well that didn't work" pile.

Posted: Fri Oct 05, 2007 8:36 am
by mikeac
Damn, that was the answer I was worried I'd get...

hmm

Posted: Fri Oct 05, 2007 9:00 am
by Uncle Jesse
You're trying to connect copper pipe to PVC? I'd find the right sized rubber grommet at any decent hardware store, slip it over the copper tube and then drill the appropriate sized hole in the PVC to mount it.

Posted: Fri Oct 05, 2007 2:59 pm
by mikeac
It'll stay water tight??

more

Posted: Fri Oct 05, 2007 3:59 pm
by Uncle Jesse
It should yeh. I'm sure you can find a rubber grommet with an inner diameter to match the size of your copper tubing.

Posted: Fri Oct 05, 2007 7:31 pm
by DestructoMutt
might this be one application where silicone sealant would be acceptable?

Posted: Fri Oct 05, 2007 8:59 pm
by Husker
Silicone would be fine here (if it can be made to be water tight under pressure. Silicone would flex under the different expansion rates of the copper and PVC.

But I think the rubber grommet solution floated by UJ sounds like the best solution.

H.

Posted: Sat Oct 06, 2007 12:40 am
by Rudi
Maybe use UJ's idea and if it leaks use some silicone as well?

Posted: Sat Oct 06, 2007 2:04 am
by bourbonbob
Do it properly. I used PVC casings on condensers with rubber grommets when I first started but it didn't feel right. Use proven materials, they look better and last forever, if they are soldered/brazed correctly?

Posted: Sat Oct 06, 2007 2:09 am
by Rudi
Yep couldnt agree more nothings better than a nice all copper liebig well maybe a big coil in a bucket or a........... well you get my drift!

Posted: Sat Oct 06, 2007 7:35 am
by mikeac
I'd love to make a copper one, and that'll be my next project, but PVC is so much cheaper! I also don't have room for a worm/bucket condenser..I've tried the silicone but wasn't too impressed by it. I'll try the grommets for sure

Thanks for all the help

Silicone

Posted: Wed Oct 10, 2007 4:56 pm
by helmingstay
i have a hard time getting all my measurements at home and then going to the store and getting everything right the first time. I like silicone's "fill-in-the-blanks" ability, and i don't mind the ugly-factor - i think it adds charm :)

I've used silicone from copper to copper (outside vapor path, of course). It can take much longer than advertised to cure if it's applied thick in unventilated spaces - up to a week in my experience, whereas the package said 24-48 hours.

expensive sealant seems worthwhile, especially since you don't need much. aquarium sealant from walmart, for example, doesn't contain all the "extra" spaceage antimold stuff...

Posted: Fri Oct 12, 2007 1:51 pm
by mikeac
So I've wandered through three hardware stores (Home Depot, Home-Do-it-Center and Lowes) and couldn't find grommets in any of them... What else are they used for? Any viable story to tell the hardware people when asking what they''re for??

Posted: Sat Oct 13, 2007 5:04 pm
by TRANSPLANTED HILLBILLY
Your insulating a wiring harness thru the firewall of a car your workin on. Or anysuch story that sounds resonable should do fine. Or just send the wife, all she has to do is say "I dont know" :shock: :lol:

Posted: Sat Oct 13, 2007 6:58 pm
by HookLine
mikeac wrote:So I've wandered through three hardware stores (Home Depot, Home-Do-it-Center and Lowes) and couldn't find grommets in any of them... What else are they used for? Any viable story to tell the hardware people when asking what they''re for??
There are different types, and they are used in all sorts of situations, usually for protecting electrical cables, but other stuff as well like sealing a join (what you want it for). Electrical suppliers usually have a range. Car firewall is a good a story as any. I have bought dozens over the years, and never been asked what they are for. Most businesses don't give a rat's behind what you do with it, as long as you pay 'em. I wouldn't worry about it, just go buy it.

Posted: Sun Oct 14, 2007 7:50 pm
by mikeac
TRANSPLANTED HILLBILLY wrote:Your insulating a wiring harness thru the firewall of a car your workin on. Or anysuch story that sounds resonable should do fine. Or just send the wife, all she has to do is say "I dont know" :shock: :lol:
Sent a friend... "I don't know" was the story and we found em' just got to grow a pair and stop being so paranoid I geuss... Thanks for the help!!

wow

Posted: Sun Oct 14, 2007 7:54 pm
by Uncle Jesse
I find that kinda hard to believe.

First hit on google search for "rubber grommet"

http://minorrubber.thomasnet.com/catego ... r-grommets

idea

Posted: Sun Oct 14, 2007 7:55 pm
by Uncle Jesse
Try auto parts stores perhaps. They often have a set of drawers dedicated to rubber bushings, grommets, small plastic clips and so on which often break in automobiles.

Posted: Mon Oct 15, 2007 3:59 am
by Johnny Reb
TRANSPLANTED HILLBILLY wrote:Your insulating a wiring harness thru the firewall of a car your workin on. Or anysuch story that sounds resonable should do fine. Or just send the wife, all she has to do is say "I dont know" :shock: :lol:
Or you could say the wife sent me and I dont know :lol:

Johnny Reb

Posted: Mon Oct 15, 2007 3:21 pm
by TRANSPLANTED HILLBILLY
Ah, an M.D. of Spin. :lol: :lol: :lol: :lol:

yeh

Posted: Mon Oct 15, 2007 3:56 pm
by Uncle Jesse
"She fixes all the appliances...she's got the blender in a hundred pieces and sent me for this."

Re: yeh

Posted: Mon Oct 15, 2007 11:10 pm
by mikeac
Uncle Jesse wrote:"She fixes all the appliances...she's got the blender in a hundred pieces and sent me for this."
That should be a sticky!!! LoL! It seams people are always feeling paranoid about buying stuff and that seems to be the most general excuse that could work for anything:

"20kg of sugar? I donno wife's doing some canning or cooking or somth'n...I just get what I'm told...."


I Love IT!

Posted: Tue Oct 16, 2007 2:41 pm
by Cruiser
Yeah, my missus used to be paranoid about buying 20kg of sugar in one hit so bought it in small lots over a couple of days. Then she noticed other shoppers buying large quantities of sugar (shopping carts full) so now she doesn't worry.

Obviously a lot of other folks out there with a sweet tooth :D