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Thread: Polypropylene adhesive?
01-06-03, 08:45 AM #1
I'm building a waterblock, and I have a special res which requires me to glue a polycarbonate tube, to a (trimmed) polypropylene barb.
Glue here: http://forum.oc-forums.com/vb/showth...ene#post884998
It's Devcon's "Plastic Welder".
It works very well with polycarbonate, but unfortunately, it's quite useless with polypropylene.
Does anyone know of an adhesive that'll work well with both materials (polycarbonate and polypropylene)?
More details on the block/res here:
01-06-03, 08:44 PM #2
A bit more info:
Polypropylene is considered a low-energy plastic, which gives it similar properties to Teflon or Polyethylene. It's notorious for being hard to bond.
A cyanoacrylate (superglue) might work, but then it may not stick to the polycarbonate, which could also work with a meta acrylate adhesive...
01-06-03, 09:54 PM #3
I'm using quite a bit of polypropylene rope and usually melt the ends to prevent unraveling. The "liquid" poly seems to stick VERY good. So maybe try some heat gun or such.
01-06-03, 10:00 PM #4
01-06-03, 10:03 PM #5
Hum... I was hoping to avoid having to heat it up.
I found that Devcon also makes a methacrylate (correctly spelled this time!) which should work very well.
Composite Welder FS (PDF)
Now all I have to do, is find it!
01-06-03, 10:12 PM #6Originally posted by JFettig
why dont you just GOOP it in? lol, it sticks really good
01-06-03, 10:13 PM #7
Now all I have to do, is find it!
- Join Date
- Jan 2002
- sj, ca, usa
01-06-03, 10:18 PM #8
01-06-03, 11:39 PM #9
We used an industrial 2 part epoxy called "Lord's Adhesive" at work to weld poly. It smells (vent booth), and it's baby sh*t brown resembling liquid nails, but man would it hold. It came in the same kind of double-barreled syringe as devcon does.
The laser housings we used it on were milspec hermetically sealed and vacuumed, plus it was a construction site laser, so it was tough enough.
Pull out your google, bud...I have no idea where to find it at.
01-07-03, 01:46 AM #10
yeah methacrylates are absolutely useless on polypropylene/ethylene.
they actually work by dissolving the plastic a bit, that's why they stick so well to other plastics.
I wouldn't bet on epoxy either... but you could try REALLY roughening it up, and maybe breaking up the surface a bit so that the epoxy can get a better hold.
01-07-03, 08:10 AM #11
SuperGlue might work, but it would be brittle. Also the fumes from it make the polycarb foggy around it.We have a local store called PVC Supply, not sure if its a chain, but they rent "plastic welders" for like $25/day. Its basically a focused heatgun with plastic rods you kinda braze the joint with. Have you got pics of what you're trying to join? If its barbs or similar, maybe you should drill/tap the polycarb?
01-07-03, 08:16 AM #12
01-07-03, 11:28 AM #13
Thanks to all!
I contacted 3M, and they suggested DP-8005, or DP-8010 "Structural Plastic" adhesive, except that it won't withstand methanol (part of my cooling solution).
I'm waiting on replies from Loctite, Lepage and Devcon.
JB Weld has no usefull info whatsoever on their website, but hech, I've got some, so I'll try it out on a scrap piece.
01-07-03, 02:51 PM #14
Devcon says: "We don't have a solution, but consider abs or nylon, instead of polypropylene, in which case you can use the Plastic Welder".
It's actually a good idea...
01-07-03, 04:57 PM #15
Next case I build, I'm ordering sheet PVC. It looks purty white (or grey), and I know it's waterproof, and the adhesive is available anywhere. You can also machine it like wood, using woodworking tools, and you can tap it too!
Sounds like everything I'd need in one product (except for being clear in spots, that's what plexi is for).
01-07-03, 05:49 PM #16
I've used clear PVC primer (schedule 40) and PVC cement, and it's really nice stuff to work with: rock solid in minutes. I used Goop where I didn't have a good seal.
I found that Lord company you mentionned earlier:
but there's not a lot of info. I might e-mail them, dunno. They do mention using a primer for hard-to-bond plastics; maybe I should try that PVC primer...
What I'm trying to bond is a clear polycarbonate tube, 1 1/2 ID, to a polypropylene barb, 1 1/2. The barb is needed to screw into the res. I did rough up the polypropylene, but only because it was a tad bigger than 1 1/2.
Now if I can find a nylon barb, I'll be all set.
01-07-03, 08:22 PM #17
The PVC Primer is MEK, I doubt it'll do anything to the polyprop fitting other than clean it. Do I understand right, you are putting the polycarb tube inside the threaded part of the pp threaded barb? If so how long is the tube and whats on the other end of it?
How about some pics.
01-08-03, 08:31 AM #18
"PP is the more difficult of your two substrates to bond. Our best
solution is to apply Primer 770 to the PP, then try one of our cyanoacrylates, such as 401. This should give you a good bond, but you would need to test for the fluid exposure, as cyanoacrylates do not typically have the best long-term resistance
to water. Another possibility with better fluid resistance, but lower adhesion to PP, would be a UV acrylic, such as 3105. The datasheets can be downloaded from our website."
I'll try to post a diagram of the assembly.
01-08-03, 08:57 AM #19
01-15-03, 07:22 PM #20
OMG, you're hooking that to your CPU???
you better have a darn good mounting or you're gonna break your mobo in half!!!