# Table saw fence face (UHMW or HDPE) question



## KGRRSteve (Dec 12, 2012)

Doing the final setup on my new Steel City cabinet table saw and I'm getting some funny readings when trying to set the fence parallel to the miter slot. This is on the SC Industrial Fence with the white plastic faces mounted to a steel tube main frame.

I'm thinking I may need to open it up and check the mounting bolts and verify that none of the washers ended up between the plastic and the fence body, but before I do I thought I'd ask what kind of tolerance the rest of you are seeing on this kind of fence face. How true is the face from one end to the other? How many thou' would you expect to see as far as consistency along the face? For example, if you set the face to be exactly parallel to the miter slot at both ends, how much variation would you put up with in between those two point?

Do you all like this material for the fence face, or do you change it out for a different material?


----------



## knotscott (Feb 27, 2009)

UHMW and HDPE are known to have some variability…sometimes its from the holding screws being too tight, other times it's just variability. It's pretty easy to shim the low spots. I've also heard of people who've put the stuff on a jointer to flatten it, but I haven't tried that.


----------



## KGRRSteve (Dec 12, 2012)

Thanks Scott.

I wonder how much variation is "too" much?
0.002?
0.005?
0.010?
0.020?


----------



## KGRRSteve (Dec 12, 2012)

Anybody?

I'm seeing, in a couple of locations, bulges of between 0.005 and 0.013". Is that typical or is it too much?


----------



## Dusty56 (Apr 20, 2008)

When I bought my JET cabinet saw , the "plastic" fence faces were all distorted , making a straight cut nearly impossible. I contacted the manufacturer and they sent me new faces , no charge : )


----------



## JesseTutt (Aug 15, 2012)

My Delta contractor's saw came with the 32" UniFence which is extruded aluminum. There was a twist in the fence of about 35/1000s. I have since replaced with the Taylor Products Incra LS-TS fence. This fence is within 2/1000s horizontal or vertical. The only problem is that is not friendly to sliding fixtures.

How accurate is accurate? It depends on you. Remember that, by Murphy's Law, all the inaccuracies will add together. So worst case if you are joining 5 pieces together and each is off by 1/64 (0.015)" the total will be off by 5 times 1/64 or over 1/16". Can you live with this? Or, are you luck and will one piece be 1/64" over and the next be 1/64" under?

I started, out of high school, working for a company that built (machine) tools for factories. I worked with machinists who routinely worked to 1/1000". So I tend to be more obsessive about accuracy.

Someone else will probably jump in and mention wood movement which will distort any measurement depending on time, temperature, humidly, etc.


----------



## paulnwa (May 22, 2011)

The Delta Unifence on my saw is an aluminum extrusion, so I don't have the problem you are experiencing. However, if I had to choose between UHMW or HDPE, I would choose UHMW, because it is a very wear resistant material-so much so that UHMW is frequently used for guides in steel conveyor systems.


----------



## KGRRSteve (Dec 12, 2012)

Thanks all.

Regarding getting replacement side plates from Steel City, it turns out that there was a manufacturing defect last year in that some of the side panels were built upside down, resulting in an incorrect fence-to-table clearance. The service rep said that they thought they had replaced them all, but they missed mine since it was in Amazon's stock and not in the normal factory supply chain. They will replace the side plates for me, but they are currently out of stock and I probably won't get the replacements until the second quarter. I want to make clear that I have been more than happy with Steel City customer service through all of this - very responsive and up-front and are working hard to keep me satisfied.

In the meantime, it is possible to flip the side plates over, with the only downside being the radiused top corners are now on the bottom. I have made this change and have been trying to true the fence to the miter slot, and have (as mentioned above) been having mixed results. It appears to me that the inconsistencies I'm seeing are located in between the mounting bolt locations and the plastic is bulging very slightly. I can push on the face and watch the dial indicator move a few thou back towards the fence. Since the irregularities in the fence can be pushed out, I'm guessing that they are not quite as serious as if they were a permanent deflection in the material, and that they would have a corresponding lesser influence on the straightness of the cut. Even so, I'm not satisfied with the current situation.

(Regarding Paul's comment regarding the two types of plastics, I'm really not trying to decide which to use, I'm just not sure which material the existing sides are made of - it appears to be UHMW to me (I'm familiar from a past custom machinery building job), but I suppose it could be something else so I just put both types in the title. I'm not really concerned either way, just didn't want to get sidetracked by being corrected if I used the wrong word.  )

Anyway, I'm holding out hope that the replacement fence sides will be "truer" than the current set.

In the meantime I think I'll build up some of my own to try. I'm thinking of using 1/2" baltic birch plywood and face it with melamine (or maybe hardboard). Suggestions on which to use? Or an alternate method/material?

Thanks for the help!


----------



## Dusty56 (Apr 20, 2008)

They must be very thin if you can press on them and see the deflection. Mine are roughly 3/4" thick.
Glad to hear that SC will be helping you out eventually : )


----------



## KGRRSteve (Dec 12, 2012)

"They must be very thin if you can press on them and see the deflection. Mine are roughly 3/4" thick.
Glad to hear that SC will be helping you out eventually : )"

Mine are about 1/2" thick. I can't visually see them move, but the movement shows on the dial indicator that I have pressed against the face in that area.


----------



## Dusty56 (Apr 20, 2008)

Got it : ) So it could just be a surface irregularity versus actual movement.


----------



## KGRRSteve (Dec 12, 2012)

I'm going to try 1/2" baltic birch plywood with hardboard facing:










(guard shown for demonstration purposed only  )


----------



## KGRRSteve (Dec 12, 2012)

FYI, 6 years later and I'm still using these fence faces. True and smooth…happy with my decision.


----------



## therealSteveN (Oct 29, 2016)

I've seen all of the plastics, bend, bow, and just about do a dance in the heat, and I'm in Ohio, not as hot as humid here.

Baltic Birch plywood, and MDF are both much more dimensionally stable. Just make sure to support them well, and keep the MDF dry.


----------

