# Gluing Delrin



## kcmillin (Oct 26, 2010)

What, if any, type of glue can I use to join two pieces of delrin (acetal)?

Will a press fit hold nicely?

I am trying to come up with a design for a distributer cap.

Kel


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## Brian Rupnow (Oct 26, 2010)

I don't think you can glue Delrin.


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## Metal Butcher (Oct 26, 2010)

kcmillin  said:
			
		

> What, if any, type of glue can I use to join two pieces of delrin (acetal)?
> 
> Will a press fit hold nicely?
> 
> ...



Hi Kel, you could try some Bondit b45th. I think McMaster Carr might carry it.

http://www.reltekllc.com/bondit-b45th.html

Don't know what all of this below means, but it was fun reading. ???

http://en.wikipedia.org/wiki/Acetal

-MB


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## Metal Butcher (Oct 26, 2010)

Here is something that may work. Etching the surface's seems to be a necessity.

http://www.loctiteproducts.com/products/detail.asp?catid=17&subid=40&plid=661

[ame]http://www.youtube.com/watch?v=JTsVF9nF-3E[/ame]

-MB


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## Peter. (Oct 30, 2010)

I followed Evan Williams' guide to making leadscrew nuts from Acetal by heating the leadscrew with a heat gun and it welded the two halves of the nut together very well. Might be possible to do a variation of this?


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## Blogwitch (Oct 30, 2010)

Delrin is usually welded. 

When I was in work. we used to have cleaning tanks welded up out of delrin sheet.


Bogs


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## Ed T (Nov 17, 2010)

Nothing to add on the glueing question, but you might want to check into the moisture absorbtion of DELRIN. Might make it a poor choice for a distributor cap.


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## Lamachina58 (Nov 17, 2010)

I've done a bit of prototype work and a lot if injection molding of Acetal (Delrin is tm). I never have bonded parts but if I can explain this, have created a mechanical "lock" made of epoxy.
If you have a shaft in a bushing. Groove the i.d. of the bushing and at the same location, groove the shaft. Assemble with those grooves full of epoxy and at the right location. You essentially have a solid o-ring and neither part can move. I've done that with a lot of dis similar materials, no threading and it doesn't take much of a groove.
Delrin doesn't absorb much moisture but for heat resistance and electrical situations I have used Ultem. Very machinable, good temperature resistance, expensive but I use onlinmetals and they cut short pieces. Ten buck for a foot of 1" dia.
I am new to forums, can I mention a supplier??


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## jpeter (Nov 17, 2010)

I've made distributor caps from Delrin. They work great. Don't work well wet though. Need to dry out after cleaning.


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## jmassen418 (Apr 9, 2013)

Hi,

I just tried Plastic Weld from Plastruct. No good.


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## canadianhorsepower (Apr 9, 2013)

kcmillin said:


> What, if any, type of glue can I use to join two pieces of delrin (acetal)?
> 
> Will a press fit hold nicely?
> 
> ...


 
can't glue Delrin, my supplier told me so but you can weld it with heat
I by some 1/6 or 1/16 Delrin rod and use the hot air welder in the picture
it works perfectly. That heater can produce enought heat:fan: I use it to silver solder also even copper pluming no flames great.


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## rcfreak177 (Apr 9, 2013)

Hi Kel,

Have you tried Loctite 406 ?, that stuff glues almost anything together. Including my fingers to tools, parts, my other fingers and so on.
I love the stuff and always keep a small bottle in the fridge, much to my wife's disgust.

http://www.loctite.com.au/cps/rde/x...tredDotUID=productfinder&redDotUID=000001G2ZP

Baz.


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## rcfreak177 (Apr 9, 2013)

Just found this

http://www.reltekllc.com/adhesives-for-delrin.htm

Edit, Maybe I should have read all the posts, Metal Butcher has already suggested Bondit.

Cheers,
Baz.


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## jgedde (Apr 9, 2013)

Years back, we went through this exercise with a totalizing water flowmeter design. The two halves of the impeller housing assembly were Delrin.

We tried everything under the sun, including having the Loctite adhesive guys come in and advise. They had some kind of etchant/adhesive solution. Even that didn't work out consistently.

We ended up having the two halves ultrasonically welded...

John


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## jgedde (Apr 9, 2013)

rcfreak177 said:


> Just found this
> 
> http://www.reltekllc.com/adhesives-for-delrin.htm
> 
> ...


 
That stuff sounds too good to be true...  First they make a point of saying the manufacturers of Delrin say it can't be glued.  Then they say it can be if you're using their product.  They go onto say you can bond silicone with it.  That raised my level of skepticism a great deal.

From the fact they say the surfaces should be scuffed, I'm venturing to say this stuff isn't really an adhesive but more of a cement.  In other words, a mechanical bond rather than a molecular bond.  That said, I wouldn't expect good tensile strength.

But, if the stuff is inexpensive, it might be worth a try.  I'd be curious myself how well it works...

John


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## jack620 (Apr 9, 2013)

The following notes may help. They were extracted from these DuPont Application Notes:

http://plastics.dupont.com/plastics/pdflit/americas/delrin/230323c.pdf


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## Walsheng (Apr 9, 2013)

If you do use heat to weld it together be careful not to overheat it.  I worked in a 60,000 square foot molding plant that we had to evacuate for a day after the barrel on a press lost a thermo-couple and filled the factory with super smelly smoke.  The plant smelled like formaldehyde for weeks after that.  Very nauseating.

John


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## Forestgnome (Apr 10, 2013)

Lamachina58 said:


> I've done a bit of prototype work and a lot if injection molding of Acetal (Delrin is tm). I never have bonded parts but if I can explain this, have created a mechanical "lock" made of epoxy.
> If you have a shaft in a bushing. Groove the i.d. of the bushing and at the same location, groove the shaft. Assemble with those grooves full of epoxy and at the right location. You essentially have a solid o-ring and neither part can move. I've done that with a lot of dis similar materials, no threading and it doesn't take much of a groove.
> Delrin doesn't absorb much moisture but for heat resistance and electrical situations I have used Ultem. Very machinable, good temperature resistance, expensive but I use onlinmetals and they cut short pieces. Ten buck for a foot of 1" dia.
> I am new to forums, can I mention a supplier??



That's what I do. I make some special stands that use a Delrin post. I cut opposing grooves in the Delrin and in the hole in the aluminum, spread JB Weld in both grooves, then assemble with a little twist at the end. I have another item that I use an interference fit, works nicely. I was just looking at the numbers the other day. There's about a 3.5 to 1 difference in the expansion ratio between aluminum and Delrin, Delrin being the greater expansion.


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## Mosey (Apr 12, 2013)

I have glued a tiny magnet to a block of Delrin for my Hall Effect ignition system, and it seems to hold quite well. It does not take any load other than centrifugal force, and the Delrin was rough from milling, with a fine-grained surface. Wish me luck? Will it stay on there at 5000 rpm's?
What do you think?
Mosey


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## canadianhorsepower (Apr 12, 2013)

> Wish me luck? Will it stay on there at 5000 rpm's?


 
put safety goggle on  and take this position:hDe:


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## va4ngo (Apr 12, 2013)

Mosey, i fully agree with Canadian horsepower.
Lamachina, i kike your groove idea with epoxy


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