HDPE - new to me; FYI

[Bruce Seidner]

I am building one of those aircraft carrier sized mobile TS/router stations that will need to scoot under a tall garage wall mounted assembly table to allow room for this behemoth to berth when not in use. The Vega Pro 50" TS fence dictates the length and the BenchDog Prolift router plate demands substance. (It is beast.)

I had been looking for phenolic plywood and you would think I was asking for cheese in China. I tried all the advise I previously received on this forum but no one in the concrete forms business or any of the specialty plywood people in East TN had any supplier. We have a Woodcrafters but the phenolic ply they sell is only 24 inches wide and it is about $50 a sheet. It is not especially robust and while I don't doubt the quality of the plywood, the phenolic is more like a veneer. I did not like the Formica I was finding, also around $50 a sheet, so I went to a Piedmont Plastic (national chain) store they have here and found a 4'x8'x 1/8" sheet of HDPE for $60 that I am experimenting with. I had a chance to actually see and touch all manner of material including PVC, LDPE, UHMW, phenolic, Starboard, ABS etc. In terms of cost the HDPE in 1/8" was quite reasonable. And it seems more workable in terms of welding, cutting, and did I mention cost.

I found a few expensive specialty glues that are said to bond to HDPE, but I will be using a thin flat head carriage bolt called an "elevator bolt", countersunk to keep the top in place. If you haven't seen one do check them out. It is just shy of an inch round 31/32" and thin as a dime with a 1/4"-20 thread. The only force on the laminate surface will be the sheer of wood passing over it so I don't think it will need many bolts to keep it in place. Kinda spanky rivet industrial aesthetic rather than a Shaker or Queen Anne. An engineer friend expressed concern that I not cinch the bolts tightly because that might deform the HDPE over time and introduce wrinkles. New material to me but it is really tough and really slick. Should be interesting.

[Jim O'Dell]

My fear on HDPE that thin would be buckling, either the material moving, or your substrate moving with temp/humidity. Maybe make the holes in your substrate for your elevator bolts larger than the threads and use fender washers under the nuts so that you have a way to loosen and flatten the HDPE IF it develops a problem.
Curious why you didn't like the high pressure laminates. I love mine. The factory finishes that have a very slight texture to them seem to let materials of all sorts glide over them, but still let you pop dried glue off if you use the surface for assembly like I do.
Be sure to post some pictures and let us know how it works for you!!! Jim.

[Bruce Seidner]

The main issue with the phenolic ply I could find was the form factor. The only material I could find without driving to Atlanta was 24"x48". I would have gone with it, in spite of the expense, if it were full size. My saw table is 27" wide and I toyed with the idea of having the phenolic ply sit inside a frame that would make up the 3" but at my next stop I found the HDPE and thought I would give it a try.

But your points are well taken and clearly this material is on the Gumby side of things. At least I am in no danger of cracking it.

[Jim O'Dell]

I recently made a new extension table for my less than year old G0691 TS. Also 27" deep. I used 1/2" MDF to build a torsion box about 26 13/16" deep for the table and about 50" wide. I then used black sheet laminate from Home Depot at 42.00 per 4 X 8 sheet and covered the sides and then the top. Nice and flat and should last me my lifetime. I got a little fancier on this top because the front edge of the cast iron table has a bevel on it. I put an oak edge on the front, laminated over it, and tried to mimic the bevel. I cut a little too deep, but it looks fine, and doesn't have a sharp edge like the laminate can be if not eased with a bevel or round over bit. Certainly thicker material than what is found on melamine covered boards or even the phenolic ply/MDF. Jim.

[Bruce Seidner]

In the spirit of "anything worth doing is worth overdoing" I wanted to try and use a new material. But I agree that having a bomb proof adhesive to a quality laminate will last you a lifetime. The cost of the HDPE and the laminate where the same. The "only" downside of the HDPE is that I don't know if it will be stable and I have no reliable way to adhere it to the extension table. Details, details.

I have some heat guns and picked up a plastic welding unit from Harbor Freight. I have been reading about welding HDPE and it is kinda cool. I am going to see about either bending a couple 90's on the width of the top and see if this helps with the mechanical stability of the material on the table top. If it is not too much of a mess I might weld and make a "box" that will wrap the top, or that is the plan. Just curious. Well, and a bit nerdy. But guilty as charged.

[Bob Wingard]

If you're in E. Tennessee .. call Jeffries Woodworks in Knoxville. They had some larger sheets a week ago when I was there. Don't remember if they were 4X8 or 4X4.

[Bruce Seidner]

Jeffries Woodworks in Knoxville is a blessing and we are lucky to have such a dedicated, honest, and knowledgeable wife/husband team running what is a wood jewelry store. They special order, slice, dice, and wrangle about anything you ask down to a reasonable size.

But they have tried on several occasions to find a source of phenolic plywood for me and unless I want to invest in a truck load, They cannot buy a few sheets. They don't have the demand and I can't buy a truck load.

But, good suggestion. They are the best.

[Bob Wingard]

For the life of me, I can't comprehend why people post questions here, and don't actually read the responses !!! !!! !!!

[Mitchell Garnett]

I recently made a new extension table for my less than year old G0691 TS. Also 27" deep. I used 1/2" MDF to build a torsion box about 26 13/16" deep for the table and about 50" wide.

I've been thinking about doing something similar (and I have enough left over black laminate from another project). If it isn't too inconvenient would be able to post a photo or two?

(I hope this doesn't consistute highjacking the thread...)

Mitch