[KevinWilkins]

I'm going to try some POM plastic for grip scales on my kitchen knives (this is widely used for knives in the food service industry) and was wondering what type of adhesive would be recomended to place between the grip scale and the knife tang.

The grips will be mechanically held in place with machine screws and threaded inserts passing through the tang, however I want a thin layer of adhesive (or similiar) to form a gasket between the grip and the tang to keep moisture from getting between the two parts.

For the other knives with wood or other grips I use slow setting epoxy which works great. I don't think the epoxy will stick to the POM however.

Thanks in advance for any ideas! Here's a pic of one grip made from Chinese Bamboo:

http://www.wilkins-knives.com/ryback...m_ecloseup.jpg

[JanHenning]

I have used Stabilit Express on plastics, where other types of glue won't stick. It's made by Pattex in Germany.

In German:
http://www.pattex.de/Pattex_Stabilit...ss.1513.0.html

In English:
http://www.hobby-lobby.com/adhesive.htm

Beautyful knife handles you make!

[KevinWilkins]

Thanks! I did read the stuff about Stailit and it says it's NOT for Polyimide ... isnt that the same as POM or Hostaform? I think I'll give Pattex a call next week.

[beone]

Check some of the R/C airplane sites. At least one manufactrer (i think Pacer) makes an instant glue specifically for plastic. Worth a try. Surprisingly you want a glue that dosn't actually get hard(think rubber) else the different rates of espansion of the tank and haft will cause it to separate.
Dave

[Herbertkabi]

I have the same question right now - how to bond POM,
Found out that normally no way - surface need to be etched or mechanically treated - will use the last mentioned way and then epoxy.
Cheers,
Herbert

Bonding POM
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 other plastics.

Solvent welding is typically unsuccessful on acetal polymers, due to the excellent solvent resistance of acetal. Thermal welding through various methods has been used successfully on both homopolymer and copolymer.

Polyoxymethylene (commonly referred to as POM and also known as polyacetal or polyformaldehyde) is an engineering thermoplastic used in precision parts that require high stiffness, low friction and excellent dimensional stability. It is commonly known under DuPont's trade name Delrin