As some of the previous Alaska Gold Forum users may recall, back in 2012 I designed and commissioned the manufacture of an Extruded EPDM 4-TPI (Teeth Per Inch) mat. I had contracted an EPDM extrusion manufacturer in Ohio to produce 750 pounds of the mat you see in the photo below.
I believe that after the losses associated with the beginning run wasted EPDM raw material I netted close to 1,000 linear feet at the 6 inch extrusion width and an with an overall thickness of 3/16 inch. Presently, my inventory is down to about 20 linear feet of this 6 inch extrusion, i.e. I've sold off approximately 98% of my initial inventory and expect to run out of this extruded EPDM Mat in a matter of a week or two at most.
Above you'll see this 4-TPI Sawtooth mat holding some fine Oregon Coast beach gold. The mat performs extremely well and with the majority of my sales going to beach miners located around the world that are retrofitting the stock Vortex Mat with their Gold Cubes or designing and building their own custom beach mining sluices (and as well as a few milled gold ore hard rock mines that employ my 4-TPI mat commercially).
Initially, sales were very slow owing to the fact that I did very little (basically nothing) to promote this EPDM extruded mat other than give away a few samples to various miners requesting they test the mat in their systems and give me detailed feedback. This effort was by in large a complete failure given that the vast majority of recreational placer gold miners couldn't design, set up, configure and run a beach gold sluice if their life depended on it. From my experience there really are only a handful of beach gold miners that have the experience and knowledge to design, build and operate such an critically unique thing as a beach gold sluice and very interestingly, most if not all of the world's successful beach gold miners have at one time or another hung out and shared their ideas and experiences here on Alaska Gold Forum.
Everything changed about a couple years ago as the popularity of the Gold Cube continued to increase and word got out about my Sawtooth mat design being so much more efficient and effective at capturing the extremely fine beach gold (thanks mostly to Washington Beach Mining, i.e. Rob Roy). It turned out that the design of the Gold Cube removed the vast majority of the issues and problems that beach gold miners encounter when setting up their sluices and the 4-TPI EPDM mat I had manufactured seemed to be optimally adapted for the Gold Cube when capturing extremely fine gold. I believe that in large part the successful Gold Cube design was due to the adaptation of the boil box designs that in large part had been used and promoted by an Alaska Gold Forum member, Trevor (New Zealand).
As you can see from the engineering drawing of the 4-TPI Sawtooth Mat above, the design is quite simple as contrasted with the designs of the market dominating EPDM extruded mats sold by one of my competitors.
But times do have a habit of changing. When I contacted my Ohio EPDM Extrusion manufacturer last month to order another production run I was disappointed to learn that the cost of EPDM as a raw material had more than doubled in the last 6 years which got me to thinking about alternative materials.
As most of you are already aware, EPDM isn't actually a very good material for gold sluicing in terms of it's abrasion resistance.
From the above polymer Abrasion Resistance chart the obviously superior material for sluice mat designs would be UHMW-PE which is about 20 times more slurry abrasion resistant than the very popular EPDM employed for my and many other more popular mats. So after contacting a few UHMW-PE extrusion manufacturers I was basically told that the extruded UHMW-PE mat that I wanted either couldn't be done or if it could be done it'd be prohibitively expensive to manufacture.
But not to be dissuaded from a challenge I have embarked on an engineering effort to design, assemble and operate the UHMW-PE extrusion equipment I'd need to produce my 4-TPI Sawtooth mat here at my home 24'x36' shop. Seeing that none of the experts I spoke with thought my price point was achievable, my efforts will more than likely fail miserably. Nonetheless I have begun building the UHMW-PE extrusion tooling to produce my 4-TPI Sawtooth Mat and whether I succeed or fail miserably I'll keep you posted.
In fact, I have a local machine shop machining up the last few parts of the massive 303 stainless steel extrusion tooling assembly I'll need to prove whether or not my designs are going to work.
For my next generation 4-TPI UHMW-PE extrusion tooling design I have chosen to eliminate as much unnecessary bulk and weight as possible so as to, hopefully, produce the most economical UHMW-PE extrusion practical. Compared to my 4-TPI EPDM extrusion which weighed about 16 ounces per square foot, my UHMW-PE mat will be much lighter at just 6.56 ounces per square foot (a 59% reduction in weight) which will translate to a raw material cost on par with a bulkier EPDM extrusion but with 20 times better abrasion resistance. One of the key considerations regarding market potential for the 20 times improved abrasion resistance of a UHMW-PE mat involves the commercial applications with continuous 24/7 mining operations where operating costs, maintenance and the downtime and frequency of installing replacement parts are critical factors.
I'll keep you posted (assuming you're interested).
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