HMW vs. UHMW for fence material

[boblon]

I am going to buy some material to make fence faces for a router fence.

There's a seller on e-bay that has some HMW for a decent price.

Is this OK for this application or do I really need to use UHMW stuff.

Thanks,
BobL.

[Knottscott]

I can figure out what the HMW stands for, but I know nothing about it's structure compared to UHMW plastic. The UHMW is slick and works well but is prone to non-linearities. I'd choose a formica type laminate over a ply or mdf substrait as opposed to the UHMW faces.

[boblon]

It appears this may be fairly consitent in that regard. Here's the info from the listings.

Fist the HMW stuff:
Our premium HD-HMW is very high quality, compression molded, high density (.954), high molecular weight (approximately 500,000) polyethylene. It has a cost advantage over our premium UHMW and works well in applications where high abrasion is not a problem.

Features:

• Thickness listed will have a minimum of .030 (machining stock)
• Low Coefficient of Friction
• High Impact Strength
• High Resistance to Acids and Lyes
• High Resistance to Cold
• Temperature Range of -148ºF to +176ºF

Applications Include:

• Conveyer Rails and Finished Parts used for Machinery
• Chain Guides and Belt Wear Plates
• Finished Parts for Filling Machinery
• Woodworking Jigs and Guides

Now the UHMW stuff:
Our premium UHMW is very high quality, compression molded, ultra-high molecular weight polyethylene with a molecular weight of 5 million. FDA approved for food contact.

Features:

· Thickness listed will have a minimum of .030 (machining stock)
· Very Low Coefficient of Friction and Excellent Resistance to Abrasion
· Very High Impact Strength
· High Resistance to Acids and Lyes
· Temperature Range of -459ºF to +180ºF

Applications Include:

· Wear plates and wear strips
· Chain and belt guides
· Scrapers
· Star wheels and feed screws
· Hopper and chute linings
· Woodworking jigs and guides

BobL.

[linear]

I'd use the cheaper stuff without even blinking.

[Knottscott]

The specs are what the material is manufactured to. The issues with movement and warpage usually occur after they're manufactured. I've got several strips of UHMW plastic that are 3/8" x 3" x 36" and every one of them has some wave to it. Mine were obtained from work and were taken (with permission ) from dozens of samples that exhibited the same thing. My examples aside, I read about this characteristic fairly often. I don't see it as a show stopping problem, but wanted to alert you to the fact that it's more of an issue with UHMW than with some other materials.

[boblon]

Thanks for the input guys.

I'm not too concerned with the slight wave as they will be secured to a flat fence.

I was just wondering if the HMW would be too soft for this app.

BobL.

[scorrpio]

It definitely won't be too soft.