Can Teflon ( PTFE) be glued.

[David Powell]

I am helping a friend modify an ancient grampohone. As part of our experiments we need to have the needle holder slide across the record while being held on a virtually frictionless slide.
Bronze bushes in an aluminiun tube worked, but not quite absolutely perfectly.
Muggins here suggested we try teflon bushes.
Well, machining teflon makes me think of machining cheese!
Hitting the sizes I want gets exciting.
I just wonder can teflon be glued?
Regards David Powell

[Dan Dubeau]

Yes it can. A few years ago I had to make a Teflon outer cover for a stainless lifting hook (long story). It looked like a big candy cane, and I made it in 2 halves and glued them together with a loctite product that came with a primer. I'm sure I still have that bottle around here somewhere, and you're welcome to use it to save buying some. Pretty sure it was around $50usd from McMaster if I remember right. I'll do some digging......

Prior to doing that job, I thought nothing stuck to teflon, but I was proven wrong. The glue worked great, and withheld some bend tests I did prior to completion. How it lasted in use is another story.....



I'm not 100% sure the 401 is the product I used, as it was stored separate from the primer, but I'm about 75% sure. Also not sure if either has a shelf life.

I should ad, that these adhesives were spec'd by the engineer that designed the parts. I have no idea if they lasted in service, and he's the type that wouldn't tell us if they did or not anyway. We made a lot of these hooks for him with various different coatings (rubber, paint, etc), and the machined ptfe shell was the last one. It either worked great, or he had enough of trying and moved on to another problem to solve lol.

[boslab]

We used permabond in work it’s like superglue in a glass bottle, it works ok, good rough surface if poss, bit of a rub with 60g paper.
mark

[Dan Dubeau]

Just dug up the print from Oct 2020, and the 401+770 primer is what was spec'd.

[psomero]

Certainly. PTFE is a low surface energy material, so you need an adhesive which is specifically indicated for LSE materials.

Cyanoacrylate, VHB tape, and epoxies from the usual suspects can all be had in an LSE flavor.

How will your bush attach to the rest of the assembly? Assuming it's possible to press fit or screw it down, those are also great fixing methods.

[psomero]

Yes it can. A few years ago I had to make a Teflon outer cover for a stainless lifting hook (long story). It looked like a big candy cane, and I made it in 2 halves and glued them together with a loctite product that came with a primer. I'm sure I still have that bottle around here somewhere, and you're welcome to use it to save buying some. Pretty sure it was around $50usd from McMaster if I remember right. I'll do some digging......

Prior to doing that job, I thought nothing stuck to teflon, but I was proven wrong. The glue worked great, and withheld some bend tests I did prior to completion. How it lasted in use is another story.....



I'm not 100% sure the 401 is the product I used, as it was stored separate from the primer, but I'm about 75% sure. Also not sure if either has a shelf life.

I should ad, that these adhesives were spec'd by the engineer that designed the parts. I have no idea if they lasted in service, and he's the type that wouldn't tell us if they did or not anyway. We made a lot of these hooks for him with various different coatings (rubber, paint, etc), and the machined ptfe shell was the last one. It either worked great, or he had enough of trying and moved on to another problem to solve lol.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.ellsworth.com/globalassets/literature-library/manufacturer/henkel-loctite/henkel-loctite-design-guide-plastic-bonding.pdf&ved=2ahUKEwjrhPaqxLv9AhUnJTQIHR7fAKkQF noECCAQAQ&usg=AOvVaw0gbLdhSzwvUQ48HtBlq58l

Indeed, 401 with primer is the recco'd henkel CA for teflon, see page 28, 29 of linked doc.

Those little bottles will usually dry out in about 12-18mo in my experience. I wish they sold a six pack of 0.15oz tubes, honestly.

[Fasttrack]

Asked and answered, I guess, but yeah - we use 770 primer for Teflon all the time. Loctite 401 is just cyanoacrylate ("super glue") from what I can tell. We use the Loctite brand, but generic would probably work too, assuming you used the right primer.

We also use double sided acrylic PSA tape to stick Teflon in various places. In fact, McMaster used to carry a self-adhesive Teflon sheet. For example: https://www.mcmaster.com/2208T62/

Maybe you can use this to line your sliding mechanism? Comes in different thicknesses...

[no704]

They have it in more of a tape also.

[QSIMDO]

Use the epoxy they glue down Turcite with.

[rkepler]

Use the epoxy they glue down Turcite with.

That would be 3M 2216, at least back when I did it. You did want to epoxy the ion etched side and not the slick side.

[jcfx]

Why not try a delrin bushing instead ? The friction coefficient of delrin vs teflon is very close.
You're still going to have issues with gluing, I've been messing around with plasma surface treatment
for paint adhesion ( blue tip of a torch flame passed around a part ) with decent results with wet out
jury is out on paint adhesion, you may want to try it on your part with the mentioned adhesives.

[ikdor]

I've seen ptfe been plasma treated before molding with rubber to make shaft seals. The plasma breaks the bonds at the surface so adhesives can get a grip on it. Might be hard at home though.

[jcfx]

I've seen ptfe been plasma treated before molding with rubber to make shaft seals. The plasma breaks the bonds at the surface so adhesives can get a grip on it. Might be hard at home though.

I did something a few years back where I had to glue delrin to a aluminum plunger, the glue manuf had a video on how to plasma treat parts
the blue tip of the flame was passed over the part a few times to 'excite' the surface for glueing, easily done with a small butane torch.
Still do it when I need to Sharpie label HDPE/LDPE/Polypropylene containers, I seem to recall the manuf was Masterbond, but the
video doesn't seem to be there ( site looks different ).

[David Powell]

Many thanks to all who responded with such helpful comments. I tried using some Loctite 638 which I have on hand, and rather to my surprise it worked. My application is a very light duty one, there is little load on the parts, just the need for them to slide virtually friction free,
Regards David Powell