Dupont Delrin design guide:
The adhesive joining of Delrin acetal resin is generally
limited to prototype models with low shear forces. This is because the
shear strength achieved with most adhesives is only 2 to 10% of the
available shear strength of Delrin acetal resin.
The best adhesion requires a special roughening step such as
sanding with 280 grit emery cloth.
A number of adhesives have been evaluated for bonding surfaces treated
with sanded surfaces of Delrin acetal resin to other materials. See
Table 17 for adhesives, suppliers, procedures, and bond strengths.
Delrin to Delrin? I think it's very difficult as Tom says.
I have a regular job which is a vintage car part (Radiator Cap) see
Which involves bonding a brass threaded insert into a Delrin Cap. I
use Polyurethane WOOD GLUE, the stuff that foams up. The two parts are
screwcut left hand interrupted thread cut deliberately loose to
increase surface area and improve security of the bond.
We tried over adhesives, but found this works a treat.
Not one has ever come apart.
Polyoxymethylene (POM), in the USA also commonly known under DuPont's
brand name Delrin, is an engineering plastic, a polymer with the
chemical formula -(-O-CH2-)n-. It is often marketed and used as a metal
substitute. Delrin is a lightweight, low-friction, and wear-resistant
thermoplastic with good physical and processing properties and capable
of operating in temperatures in excess of 90 degrees celsius
(approximately 200 degrees fahrenheit). According to the material
safety data sheet from DuPont, the material has a slight odor of
It is also known as polyacetal, acetal resin, polytrioxane,
polyformaldehyde, and paraformaldehyde (the latter term is usually
restricted to the short-chained polymer).
Acetal polymers are typically very difficult to bond. Special processes
and treatments have been developed to improve bonding of acetal.
Typically these processes involve surface etching, flame treatment or
mechanical abrasion. Typical etching processes involve chromic acid at
elevated temperatures. DuPont has a patented process for treating
acetal homopolymer called satinizing which creates anchor points on the
surface, giving an adhesive something to grab. There are also processes
involving oxygen plasma and corona discharge.
Once the surface is prepared, a number of adhesives can be used for
bonding. These include epoxies, polyurethanes, and cyanoacrylates.
Epoxies have shown 150-500 psi shear strength on mechanically abraded
surfaces and 500-1000 psi on chemically treated surfaces.
Cyanoacrylates are useful for bonding to metal, leather, rubber and
One of the properties of Delrin® that makes it difficult to bond to is
its low friction properties which are the result of the manufacturing
process. Delrin® can be bonded to but it requires careful preparation
and BONDiTTM brand adhesives manufactured by RELTEK LLC. BONDiTTM
products are among the few available that can be used to bond Delrin®
to itself, and to other substrates for harsh environments and long term
deployment without debonding.
Great for gluing Delrin track or hand-laid rail to ties.
I haven't used these items myself, so can't attest to the amount of
advertising hype they may contain.
Loctite make a cyanoacrylate (super glue) that works if you also use
their primer. 406, 410 IIRC are the two glues I have used. I think the
410 works better as it is thick.
It is not the adhesive that makes teh major difference, but the surface
prep. Although the Loctites are the purest off the shelf that I have found.